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The Auk 114(2):296-298, 199

How to deal with floating references on talk pages


Floating references[edit]

The correct way of dealing with floating references is to use the template {{Reflist-talk}}. This puts the refs in a neat box and keeps them with the original posting. For example, This posting contains 3 bogus refs to illustrate the use.[1][2][3]



  1. ^ This is a bogus ref to illustrate the template that prevents floating refs.
  2. ^ This is another bogus ref.
  3. ^ This is the third bogus reference


When witnessing chicks in distress, chickens show emotional and physiological responses consistent with empathy. Researchers Edgar, Paul and Nicol[1] found that in conditions where the chick was susceptible to danger, the mother hen's heart rate, body temperature and vocal alarm calls increased, and personal preening decreased. These responses occurred whether or not the chick believed they were in danger. Mother hens experienced stress-induced hyperthermia only when the chick's behavior correlated with the perceived threat. Animal maternal behavior may be perceived as empathy, however, it could be guided by the evolutionary principles of survival and not emotionality.

Both chicks and hens show an understanding of object permanence, for both partly and fully occluded objects.[2]

There are at least two forms of numeracy. The simplest is categorisation in which animals categorise two groups of objects as containing "more than..." or "less than...". Despite the apparent simplicity of this task to humans, relatively few non-human species demonstrate this ability. A more sophisticated numeracy is ordinality, which the ability to place quantities in a series. Again, this has been demonstrated in only a handful of species. Chicks have demonstrated both categorisation and ordinality.[2]


An energy-conserving strategy used by some small (< 100 g) birds (and mammals). The bird becomes inactive and unreactive to external stimuli, and reduces its metabolism causing decreases in body temperature by 4 - 35ºC below normal, respiration rate, and heart rate. Two types of torpor (sometimes termed "hypometabolism") are recognised. For some birds, such as humming birds, torpor may be entered into on a daily basis and lasts only a few hours; other behaviours such as foraging continue to occur during non-torpor. For other species, torpor may only be used in cold conditions or when food becomes limited, and may persist for weeks or even months. The extent of unresponsiveness during torpor can be great. A humming bird in deep torpor, for example with a body temperature of 18ºC, does not respond to an external stimulus such as attempts to push it from a perch; only the locking reflex of the feet stops the bird from falling. Torpor has been reported in eight orders of birds.

[3] [4]

Canopy feeding[edit]

Some herons, perhaps most notably the black heron, adopt an unusual position while hunting for prey. With their head held down in a hunting position, they sweep their wings forward to meet in front of their head, thereby forming an umbrella shaped canopy. The primaries and secondaries touch the water, the nape feathers are erected and the tail is drooped, thereby ensuring the canopy is totally enclosed. The bird may take several strides in this position. One theory about the function of this behaviour is that it reduces glare from the water surface, allowing the bird to more easily locate and catch prey. Alternatively, the shade provided by the canopy may attract fish making their capture easier. Some herons adopt a similar behaviour called double-wing feeding in which the wings are swept forward to create an area of shade, however, a canopy is not formed.[5]

Bish birds[edit]

There are several birds I can think of, but they all seem to have negative aspects you might not like to be associated with. You could try the Marabou stork which spreads its wings over its kill so that other editor-birds cannot see what they are doing - but the have the distasteful habit of excreting down their legs to keep cool. You could try the Jakana which learns to tread extremely carefully over floating editor-lilly pads - but they are often eaten alive by editor-crocodiles. My third suggestion is the Hornbill. Hornbills are known for their intelligence, long memory and fidelity - but they have the lovely habit of sealing their editor-mate into a nest hole in a tree and feeding them through a small gap.

Bish's alter egos
Bish-Marabou stork spreading wings over a kill
Bish-Jakana treading carefully
Bish-hornbill feeding a victim

Moving forward[edit]

I think most of us here will have read both favourable and unfavourable media reports about the RfC on the Daily Mail and how the decision was reached. Like it or not, we are in the spot-light - public perception about WP and how we go about making decisions in this area seem mixed at best - for instance, the RfC was the subject of a scathing joke on The Last Leg (a UK TV programme) last night. What is clear is that within WP there is a great motivation to ban/blacklist/greylist other sources. I feel it would be beneficial for both editors and public perception of our decision-making to try to make it more transparent how we go about this, before we start considering actions against other media sources. Two years ago, I got caught up in a fairly unhealthy debate about using the DM. I will not post the diff here (but it makes very interesting reading to see how the comments of some editors have changed since then) One of the approaches I suggested was to try and standardise the criteria on how we were assessing the suitability of media sources. I presented the table below - which is intended to proke thought and not as an end-point. attacks on what I have included in the table - these are only to show examples and do not represent my views.

Newspaper Country Age (years) Does the source have a good or bad reputation for - Do other sources Another column
Checking facts
Editorial oversight
Reporting on this subject
Correcting its mistakes
Preferentially reporting scandal or rumours
Preferentially reporting rare events
Conflict of interest
Report contradictory facts
Report mistakes by the source
Category 1
Category 2
Daily Mail UK 65
Daily Express UK .
Daily Telegraph UK .
The Guardian UK .
Notes here

aThere is editorial oversight, but the editor is clearly biased against feminist issues

I also suggested a "traffic light" system on how we assess the suitability of media sources. If we are to place an automatic pop-up message when editors try to use the Daily Mail, this could perhaps apply to other journals where we might reach consensus that caution is required, but in a graded approach.

Newspaper name Country Rating Comments
The Daily Perfect UK RS compliant Use without hesitation
The International Truth US RS compliant Totally trustworthy
The Daily Make It Up UK RS compliant in some contexts Use with great caution - totally unacceptable for biographies
The Daily Sensation UK RS compliant in some contexts Use with great caution. Very poor reputation for fact checking
The Weekly Made-up Chronicle US non-RS compliant Do not use without opening Talk thread to discuss
The Daily Sleaze UK Non-RS compliant This source should not be used anywhere on Wikipedia except in exceptional circumstances

DrChrissy (talk) 17:35, 14 July 2015 (UTC)

Moving forward[edit]

I think most of us here will have read both favourable and unfavourable media reports about the RfC and how the decision was reached. Public perception about WP and its decision making in this seem mixed at best - for instance, the RfC was the subject of a scathing joke on The Last Leg last night. What is clear is that within WP there is a great motivation to ban/blacklist other sources. I feel it would be beneficial for both editors and public perception of our decision making

Octopus opening a container with a screw cap
Legislation on the protection of invertebrates in research adapted from[6]
Country or
Invertebrates protected Legislation
(some states)
Cephalopods Government National Health and Medical
Research Council's Code of Practice (2004)
Canada Cephalopods and “some other higher invertebrates” Canadian Council on Animal Care (1991)
EU Cephalopods EU Directive 2010/63/EU
New Zealand Octopus, squid, crab, lobster, crayfish Animal Welfare Act (1999)
Norway Squid, octopi, decapod crustaceans, honeybees Norwegian Animal Welfare Act (2009)
Switzerland Cephalopods, decapod crustaceans Swiss Animal Welfare Act (2008)

My comment is that your contributions here are garbage. jps (talk) 14:45, 29 January 2016 (UTC) [1] “My god but you are tiresome. If you don't like a conversation, don't comment in it! For someone who complains about harassment, you sure do seem to like to wikihound.” [2]

In non-human animals, cortisol is often used as an indicator of stress and can be measured in blood,[7] saliva,[8] urine,[9] hair,[10] and faeces.[11][10]

On another user's Talk page, @JzG:/@Guy:, an admin, wrote Sage, it would be extremely unwise to take up this offer. Robert is promoting a fake disease, and if you go down that route you will be aligning yourself with the pseudoscientists and woo-mongers, and that will get you a full site ban much more quickly than what you're doing now. Guy (Help!) 09:05, 3 November 2016 (UTC)[3]. It concerns me that an admin might take into account who one aligns oneself with in dealing out a full site ban (or indeed sanctions of any kind). I would have thought sanctions were about disruption to the project, not who your friends are. Is it a widespread view among admins that aligning oneself with certain people can lead to a site ban? DrChrissy (talk) 20:36, 4 November 2016 (UTC)

Examples of the major classes of fish
(Pacific hagfish)
(Horn shark)
(Brown trout)


I have been trying to discuss with administrator @JzG: edits that they have made about me. I have raised this on their talk page twice, but they are refusing to engage in meaningful discussion - see here [4] and here [5]. Which is the appropriate noticeboard to take this to, or because Jzg is an admin, should this go straight to ArbCom? DrChrissy (talk) 21:10, 18 August 2016 (UTC)

If you edit on [[ ]] you should expect to be followed to pages you subsequently edit where you will be harassed and hounded. This will be done with impunity for the perpetrators. You should not expect support from admins or other editors, despite their knowledge of this established practice of incivility.

{{Copied|from=Goat|from_oldid=|to=Goat farming|diff=}}

  • I will make 2 points here. The first is that I was not claiming Jimbo's Talk page is a TB free-zone. I am a rare(ish) visitor to this page so I am a little surprised to see the post of @Count Iblis: above. I had it explained to me once that TB's apply to every page in which the url contains "en.wikipedia". Jimbo may wish to clarify if his talk page is an exemption to this. My second point is the the recent blocks of @SageRad: and @David Tornheim:. I have watched the edits of both these editors for many months. They edit in many and varied areas (not necessarily the same). Whilst I might not always agree with their edits in article space, I can not remember a single edit in article space from either of them that I would call disruptive. In Talk pages, they both remain civil and make their points within the bounds of good wikipedian behaviour. I urge readers to seek out the comments that got them blocked and read these with an open mind. Were they violating their topic bans? Certainly they can be interpreted that way if you want to engage in mind-reading and predicting the motivations of other editors, but we are not supposed to do that. Reading their comments with an open mind shows they were making general comments about problems with Wikipedia that are current and prevalent. I would be interested to see statements made be either of them w

Pyrophilous organisms (meaning "fire loving")

Pyrophilous ("fire loving") species are known among plants, fungi[12] and animals.[13]

In insects[edit]

Pyrophilous insects are known from at least 25 families in the orders Hemiptera, Lepidoptera, Diptera and Coleoptera. Some have specialised sensors for smoke detection on their antennae and sensors for IR radiation detection on the thorax or abdomen. The smoke sensors allow the insects to detect fires from a great distance (e.g. 50 kilometres) and the IR detectors locate freshly burnt areas at a much shorter distance.[14] One example is the beetle Melanophila acuminata which locates forest fires to lay their eggs in freshly killed conifers.[15]


  1. ^ Edgar, J; Paul (Aug 2013). "Protective Mother Hens: Cognitive influences on the avian maternal response". British Journal of Animal Behavior. 86 (2): 223–229. doi:10.1016/j.anbehav.2013.05.004. Retrieved March 6, 2014.
  2. ^ a b Lori, M. (2017). "Thinking chickens: a review of cognition, emotion, and behavior in the domestic chicken". Animal Cognition: 1–21.
  3. ^ Schleucher, E. (2004). "Torpor in birds: taxonomy, energetics, and ecology". Physiological and Biochemical Zoology. 77 (6): 942–949.
  4. ^ Brigham, R.M. (1992). "Daily torpor in a free-ranging goatsucker, the common poorwill (Phalaenoptilus nuttallii)". Physiological Zoology. 65 (2): 457–472.
  5. ^ Hancock, J. and Kushlan, J.A. (2010). The Herons Handbook. A&C Black.
  6. ^ Tonkins, B.B.M. (2016). Why are cephalopods protected in scientific research in Europe?
  7. ^ van Staaveren, N., Teixeira, D.L., Hanlon, A. and Boyle, L.A. (2015). "The effect of mixing entire male pigs prior to transport to slaughter on behaviour, welfare and carcass lesions". PloS One. 10 (4): e0122841.
  8. ^ Ruis, M.A., Te Brake, J.H., Engel, B., Ekkel, E.D., Buist, W.G., Blokhuis, H.J. and Koolhaas, J.M. (1997). "The circadian rhythm of salivary cortisol in growing pigs: effects of age, gender, and stress". Physiology & Behavior. 62 (3): 623–630.
  9. ^ Schalke, E., Stichnoth, J., Ott, S. and Jones-Baade, R. (2007). "Clinical signs caused by the use of electric training collars on dogs in everyday life situations". Applied Animal Behaviour Science. 105 (4): 369–380. doi:10.1016/j.applanim.2006.11.002.
  10. ^ a b Accorsi P.A.; Carloni E.; Valsecchi P.; Viggiani R.; Garnberoni M.; Tarnanini C.; Seren E. (2008). "Cortisol determination in hair and faeces from domestic cats and dogs". General and Comparative Endocrinology. 155 (2): 392–402. doi:10.1016/j.ygcen.2007.07.002.
  11. ^ Messmann, S., Bagu, E., Robia, C. and Palme, R. (1999). "Measurement of glucocorticoid metabolite concentrations in faeces of domestic livestock". Journal of Veterinary Medicine Series A. 46 (10): 621–631.
  12. ^ Seaver, F.J. (1909). "Studies in Pyrophilous fungi: I. The occurrence and cultivation of Pyronema". Mycologia. 1 (4): 131–139.
  13. ^ [
  14. ^ Schütz, S., Weissbecker, B., Hummel, H.E., Apel, K.H., Schmitz, H. and Bleckmann, H. (1999). "Insect antenna as a smoke detector". Nature. 398 (6725): 298–299.
  15. ^ Campbell, A.L., Naik, R.R., Sowards, L. and Stone, M.O. (2002). "Biological infrared imaging and sensing". Micron. 33 (2): 211–225.

Live feather plucking[edit]

Live feather plucking is the practice of pulling feathers from fully conscious birds, usually from the breast, belly, back and necks of geese and ducks, and less frequently, chickens. The birds are usually restrained on their backs between the knees of workers for the process.

Feathers are used to fill a range of items such as bedding, clothing, gloves and furniture. The most desired feathers are the high-quality down from the soft layer of smaller feathers that cover the skin. Live feather plucking has been practiced for hundreds of years.

Feathers are collected either as a byproduct from ducks and geese slaughtered for meat, or by live plucking.


Geese usually develop their first full covering of feathers at about 8 weeks of age; they are live-plucked at 10 weeks old and up to six times a year before slaughter.[1]

Live plucking of feathers from geese is forbidden by EU legislation on animal welfare in which Article 23 (3) states that "...feathers, including down, shall not be plucked from live birds". However, when questioned about this, EU representatives stated "...the practice of harvesting feathers from live geese during the moulting period is allowed in the EU."[2]<>

live plucking is illegal in Europe and the U.S. The world’s top three down-producing countries are Hungary, Poland and China.[1]

Goat farming[edit]

The Boer goat is a widely-farmed meat breed.

Goat farming is the raising and breeding of domestic goats (Capra aegagrus hircus). It is a branch of animal husbandry. Goats are raised principally for their meat, milk, fibre and skin.

Worldwide goat population statistics[edit]

According to the Food and Agriculture Organization (FAO), the top producers of goat milk in 2008 were India (4 million metric tons), Bangladesh (2.16 million metric tons) and the Sudan (1.47 million metric tons).[3]

World goat production: Selected regions and countries, 2008
Country/Region Total animals (millions) Goat milk (MT) Goat meat (million MT)
World ----- 15.2 4.8
Africa 294.5 3.2 1.1
Nigeria 53.8 N/A 0.26
Sudan 43.1 1.47 0.19
Asia 511.3 8.89 3.4
Afghanistan 6.38 0.11 0.04
Pakistan 60.00 N/A N/A
India 125.7 4.0 0.48
Bangladesh 56.4 2.16 0.21
China 149.37 0.26 1.83
Saudi Arabia 2.2 0.076 0.024
Americas 37.3 0.54 0.15
Mexico 8.8 0.16 0.04
USA 3.1 N/A 0.022
Europe 17.86 2.59 0.012
UK 0.09 N/A N/A
France 1.2 0.58 0.007
Oceania 3.42 0.0004 0.018


The taste of goat kid meat has been reported as similar to that of spring lamb meat.[4] In some localities (e.g. the Caribbean, Bangladesh, Pakistan and India) the word “mutton” is used to describe both goat and lamb meat. However, some compare the taste of goat meat to veal or venison, depending on the age and condition of the goat. The flavour is primarily linked to the presence of 4-methyloctanoic and 4-methylnonanoic acid.[5][6]

Goat meat can be prepared in a variety of ways, including stewing, baking, grilling, barbecuing, canning, and frying; it can be minced, curried, or made into sausage. Due to its low fat content, the meat can toughen at high temperatures if cooked without additional moisture. One of the most popular goats farmed for meat is the South African Boer, introduced into the United States in the early 1990s. The New Zealand Kiko is also considered a meat breed, as is the myotonic or "fainting goat".

Milk, butter and cheese[edit]

A goat being machine milked on an organic farm

Goats produce about 2% of the world's total annual milk supply.[7] Some goats are bred specifically for milk. Unprocessed goat milk has small, well-emulsified fat globules, which means the cream remains suspended in the milk instead of rising to the top, as in unprocessed cow milk; therefore, it does not need to be homogenized. Indeed, if the milk is to be used to make cheese, homogenization is not recommended, as this changes the structure of the milk, affecting the culture's ability to coagulate the milk and the final quality and yield of cheese.[8] Dairy goats in their peak milk production (generally around the third or fourth lactation cycle) average—2.7 to 3.6 kg (6 to 8 lb)—of milk production daily—roughly 2.8 to 3.8 l (3 to 4 U.S. qt)—during a ten-month lactation, producing more just after freshening and gradually dropping in production toward the end of their lactation. The milk generally averages 3.5% butterfat.[9]

Goat milk is commonly processed into cheese, butter, ice cream, yogurt, cajeta and other products. Goat cheese is known as fromage de chèvre ("goat cheese") in France. Some varieties include Rocamadour and Montrachet.[10] Goat butter is white because goats produce milk with the yellow beta-carotene converted to a colourless form of vitamin A.


Most goats have soft insulating hairs near the skin and longer guard hairs on the surface. The desirable fibre for the textile industry is the former; it has several names including "down", "cashmere" and "pashmina". The guard hairs are of little value as they are too coarse, difficult to spin and difficult to dye. Goats are typically shorn twice a year, with an average yield of about 4.5 kg (10 lb).

In South Asia, cashmere is called "pashmina" (from Persian pashmina, "fine wool"). In the 18th and early 19th centuries, Kashmir (then called Cashmere by the British), had a thriving industry producing shawls from goat-hair imported from Tibet and Tartary through Ladakh. The shawls were introduced into Western Europe when the General in Chief of the French campaign in Egypt (1799–1802) sent one to Paris. Since these shawls were produced in the upper Kashmir and Ladakh region, the wool came to be known as "cashmere".

The cashmere goat produces a commercial quantity of cashmere wool, which is one of the most expensive natural fibres commercially produced; cashmere is very fine and soft. The cashmere goat fibre is harvested once a year, yielding around 260 g (9 oz) of down.

Angora goats produce long, curling, lustrous locks of mohair. Their entire body is covered with mohair and there are no guard hairs. The locks constantly grow to 9 cm or more in length. Angora crossbreeds, such as the pygora and the nigora, have been selected to produce mohair and/or cashgora on a smaller, easier-to-manage animal.

See also[edit]

List of goat breeds List of goat dishes


External links[edit]

Category:Goat Category:Animal breeding


  1. ^ a b c Villalobos, A. (April 1, 2010). "Down with live-plucked down". Veterinary Practice News.
  2. ^ "Live plucking of geese". December 11, 2012. Retrieved July 25, 2016. Text "European Enforcement Network of Animal Welfare Lawyers and Commissioners" ignored (help)
  3. ^ FAOSTAT 2008
  4. ^ Milk Goats. Life. Jun 18, 1945. Retrieved 2010-07-06.
  5. ^ Cramer, D.A. (1983). "Chemical compounds implicated in lamb flavor". Food Technology. 37: 249–257.
  6. ^ Wong, E., Nixon, L.N. and Johnson, B.C. (1975). "The contribution of 4-methyloctanoic (hircinoic) acid to mutton and goat meat flavor". New Zealand Journal of Agricultural Research. 18: 261–266.
  7. ^ {{cite book|author=Food and Agriculture Organisation|year=1997|title=1996 Production Yearbook|publisher=Food and Agriculture Organisation; Rome, Italy
  8. ^ Amrein-Boyes, D. (2009). 200 Easy Homemade Cheese Recipes. Robert Rose Inc; Toronto.
  9. ^ American Dairy Goat Association,
  10. ^ Chèvre cheese,


Country Flag Year title
United Kingdom Flag of the United Kingdom.svg 1986 ASPA
Philippines Flag of the Philippines.svg 1998 An act to promote animal welfare in the Phillipines, otherwise known as "The Animal Welfare Act of 1998".[7]
United Kingdom Flag of the United Kingdom.svg 1911 Protection of Animals Act 1911


In some countries, flocks of commercial poultry are force moulted to reinvigorate egg-laying. This usually involves complete withdrawal of their food and sometimes water for 7–14 days or up to 28 days.[1]. This causes a body-weight loss of 25 to 35%,[2] which stimulates the birds to lose their feathers, but also reinvigorates egg-production. Some flocks may be force moulted several times. In the US in 2003, more than 75% of all flocks were force moulted.[3]

Other methods of forced moulting include low-density diets (e.g. grape pomace, cotton seed meal, alfalfa meal)[4] or dietary manipulation to create an imbalance of a particular nutrient(s). The most important among these include manipulation of minerals including sodium (Na), calcium (Ca), iodine (I) and zinc (Zn), with full or partially reduced dietary intakes.[5]


  1. ^ Cite error: The named reference Molino et al., (2009) was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Webster, (2003) was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Yousaf and Chaudhry, (2008) was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Patwardhan and King, (2011) was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Khan et al., (2011) was invoked but never defined (see the help page).

These criticisms are based on ABF. My comment on "Whaaambulance" was to clarify the term. I had never encountered it before (perhaps it is a term widely used in the US, but it is not used here in the UK) and I was trying to save other editors the time of having to research the term. My opining that a thread was closed too quickly is based on a WP:CBAN policy which states Sanction discussions are normally kept open for at least 24 hours to allow time for comments from a broad selection of community members. "keeps going" Hardly disruptive "Comments" I was trying to offer impartial advice to an editor. More seriously, and very seriously, you have accused me of threatening a boomerang. I typed specifically that I would not be issuing a boomerang. You are seriously misrepresenting my comment to the community and I invite you to strike it.

CommentTo all those trying to deflect from JPS' incivility, let me remind you that if you are voting Oppose here, you are, in effect, supporting comments and behaviour such as

  • JPS started a sub-thread with the heading “Proposed Making Fun of DrChrissy”.[8]
  • “It's okay, James J. Lambden. We've been monitoring your off-wiki actions as well. We'll get to you in due time.” [9]
  • Lying about editors to malign them|[10]
  • “I think you have a reading comprehension problem.”[11]
  • “My darling, the issue is clearly stated and the question was answered.”[12]
I also note that 4 of these 5 examples are directed at editors other than me - this issue is not about me and JPS, it is about JPS. DrChrissy (talk) 14:36, 13 June 2016 (UTC)

Incivility Quote Comment Month Evidence (diff) Top 10
Name calling You are a **** Policy says January DIFF 1
Sexism Hello **** Guideline indicates February Diff 2
Insults Your mother was a hamster No MontyPython March DIIIIIFFFF 3


Differences between species[edit]

File:Cuttlefish komodo.jpg File:Cuttlefishhead.jpg File:Kalamar.jpg File:Flickr - JennyHuang - Huge Cuttlefish.jpg Sepia changes color vq8aq5.ogv

A cuttlefish changing its skin texture
After: Note the rougher texture of the skin

Visual signals of the common cuttlefish[1]
Chromic - light Chromic - dark Texture Posture Locomotor
White posterior triangle Anterior transverse mantle line Smooth skin Raised arms Sitting
White square Posterior transverse mantle line Coarse skin Waving arms Bottom suction
White mantle bar Anterior mantle bar Papillate skin Splayed arms Buried
White lateral stripe Posterior mantle bar Wrinkled first arms Drooping arms Hovering
White fin spots Paired mantle spots White square papillae Extended 4th arm Jetting
White fin line Median mantle stripe Major lateral papillae Flattened body Inking
White neck spots Mantle margin stripe Raised head
Iridescent ventral mantle Mantle margin scalloping Flanged fin
White zebra bands Dark fin line
White landmark spots Black zebra bands
White splotches Mottle
White major lateral papillae Latero-ventral patches
White head bar Anterior head bar
White arm triangle Posterior head bar
Pink iridophore arm stripes Pupil
White arms spots (males only) Eye ring
Dark arm stripes
Dark arms
Examples of cephalopds
The common octopus
(Octopus vulgaris)
The common cuttlefish
(Sepia officinalis)
The common squid
(Loligo vulgaris)
The palau nautilus
(Nautilus belauensis)

Pain in cephalopods is a contentious issue. Pain is a complex mental state, with a distinct perceptual quality but also associated with suffering, which is an emotional state. Because of this complexity, the presence of pain in non-human animals, or another human for that matter, cannot be determined unambiguously using observational methods, but the conclusion that animals experience pain is often inferred on the basis of likely presence of phenomenal consciousness which is deduced from comparative brain physiology as well as physical and behavioural reactions.[2]

Cephalopods are complex invertebrates, often considered to be more "advanced" than other invertebrates. They fulfill several criteria proposed as indicating that non-human animals may be capable of perceiving pain. These fulfilled criteria include having a suitable nervous system and sensory receptors, opioid receptors, reduced responses to noxious stimuli when given analgesics and local anaesthetics used for vertebrates, physiological changes to noxious stimuli, displaying protective motor reactions, exhibiting avoidance learning and making trade-offs between noxious stimulus avoidance and other motivational requirements. Furthermore, it has been argued that pain may be only one component of suffering in cephalopods,[3] others potentially include fear, anxiety, stress and distress.

Most animal welfare legislation protects only vertebrates. However, cephalopods have a special position among invertebrates in terms of their perceived ability to experience pain, which is reflected by some national and international legislation protecting them during research.

If cephalopods feel pain, there are ethical and animal welfare implications including the consequences of exposure to pollutants, practices involving commercial, aquaculture and for cephalopods used in scientific research or which are eaten. Because of the possibility that cephalopods are capable of perceiving pain, it has been suggested that "precautionary principles" should be followed with respect to human interactions and consideration of these invertebrates.


Extant cephalopods are divided into two subclasses, the Coleoidea (cuttlefish, squid, and octopus) and Nautiloidea (nautiluses). They are molluscs, meaning they are related to slugs, snails and bivalves. Cephalopods are widely regarded as the most intelligent of the invertebrates. They have well developed senses and large brains,[4] and are considered by some to be "advanced invertebrates" or an "exceptional invertebrate class".[5] About 700 living species of cephalopods have been identified.

The nervous system of cephalopods is the most complex of all the invertebrates[6] and their brain-to-body-mass ratio falls between that of endothermic and ectothermic vertebrates.[7] The brain is protected in a cartilaginous cranium.

The possibility that non-human animals may be capable of perceiving pain has a long history. Initially, this was based around theoretical and philosophical argument, but more recently has turned to scientific investigation.


René Descartes

The idea that non-human animals might not feel pain goes back to the 17th-century French philosopher, René Descartes, who argued that animals do not experience pain and suffering because they lack consciousness.[8][9][10] In 1789, the British philosopher and social reformist, Jeremy Bentham, addressed in his book An Introduction to the Principles of Morals and Legislation the issue of our treatment of animals with the following often quoted words: "The question is not, Can they reason? nor, can they talk? but, Can they suffer?"[11]

Peter Singer, a bioethicist and author of Animal Liberation published in 1975, suggested that consciousness is not necessarily the key issue: just because animals have smaller brains, or are ‘less conscious’ than humans, does not mean that they are not capable of feeling pain. He goes on further to argue that we do not assume newborn infants, people suffering from neurodegenerative brain diseases or people with learning disabilities experience less pain than we would.[12]

Bernard Rollin, the principal author of two U.S. federal laws regulating pain relief for animals, writes that researchers remained unsure into the 1980s as to whether animals experience pain, and veterinarians trained in the U.S. before 1989 were taught to simply ignore animal pain.[13] In his interactions with scientists and other veterinarians, Rollin was regularly asked to "prove" that animals are conscious, and to provide "scientifically acceptable" grounds for claiming that they feel pain.[13]

Continuing into the 1990s, discussions were further developed on the roles that philosophy and science had in understanding animal cognition and mentality.[14] In subsequent years, it was argued there was strong support for the suggestion that some animals (most likely amniotes) have at least simple conscious thoughts and feelings[15] and that the view animals feel pain differently to humans is now a minority view.[8]

Scientific investigation[edit]

Cambridge Declaration on Consciousness (2012)
The absence of a neocortex does not appear to preclude an organism from experiencing affective states. Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors. Consequently, the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses [which are cephalopods], also possess these neurological substrates.[16]

In the 20th and 21st centuries, there were many scientific investigations of pain in non-human animals.


At the turn of the century, studies were published showing that arthritic rats self-select analgesic opiates.[17] In 2014, the veterinary Journal of Small Animal Practice published an article on the recognition of pain which started – "The ability to experience pain is universally shared by all mammals..."[18] and in 2015, it was reported in the science journal Pain, that several mammalian species (rat, mouse, rabbit, cat and horse) adopt a facial expression in response to a noxious stimulus that is consistent with the expression of humans in pain.[19]


At the same time as the investigations using arthritic rats, studies were published showing that birds with gait abnormalities self-select for a diet that contains carprofen, a human analgesic.[20] In 2005, it was written "Avian pain is likely analogous to pain experienced by most mammals"[21] and in 2014, " is accepted that birds perceive and respond to noxious stimuli and that birds feel pain".[22]


Whether fish are able to perceive pain is contentious. However, teleost fishes have a suitable nervous system and sensory receptors, opioid receptors and reduced responses to noxious stimuli when given analgesics and local anaesthetics, physiological changes to noxious stimuli, displaying protective motor reactions, exhibiting avoidance learning and making trade-offs between noxious stimulus avoidance and other motivational requirements.[23][24]

Reptiles and amphibians[edit]

Veterinary articles have been published stating both reptiles[25][26][27] and amphibians[28][29][30] experience pain in a way analogous to humans, and that analgesics are effective in these two classes of vertebrates.

Argument by analogy[edit]

In 2012, the American philosopher Gary Varner reviewed the research literature on pain in animals. His findings are summarised in the following table.[23]

Argument by analogy[23]
Fish Amphibians Reptiles Birds Mammals
Has nociceptors Green tickY Green tickY Green tickY Green tickY Green tickY
Has brain Green tickY Green tickY Green tickY Green tickY Green tickY
Nociceptors and brain linked Green tickY ?[a] / Green tickY ?[b] / Green tickY ? / Green tickY Green tickY
Has endogenous opioids Green tickY Green tickY Green tickY Green tickY Green tickY
Analgesics affect responses Green tickY ?[c] ?[d] Green tickY Green tickY
Response to damaging stimuli similar to humans Green tickY Green tickY Green tickY Green tickY Green tickY


  1. ^ But see[31]
  2. ^ But see[32]
  3. ^ But see[33]
  4. ^ But see[34]

Arguing by analogy, Varner claims that any animal which exhibits the properties listed in the table could be said to experience pain. On that basis, he concludes that all vertebrates probably experience pain, but invertebrates, apart from cephalopods probably do not experience pain.[23][35]

The experience of pain[edit]

Although there are numerous definitions of pain, almost all involve two key components.

First, nociception is required.[36] This is the ability to detect noxious stimuli which evoke a reflex response that rapidly moves the entire animal, or the affected part of its body, away from the source of the stimulus. The concept of nociception does not imply any adverse, subjective "feeling" – it is a reflex action. An example in humans would be the rapid withdrawal of a finger that has touched something hot – the withdrawal occurs before any sensation of pain is actually experienced.

The second component is the experience of "pain" itself, or suffering – the internal, emotional interpretation of the nociceptive experience. Again in humans, this is when the withdrawn finger begins to hurt, moments after the withdrawal. Pain is therefore a private, emotional experience. Pain cannot be directly measured in other animals, including other humans; responses to putatively painful stimuli can be measured, but not the experience itself. To address this problem when assessing the capacity of other species to experience pain, argument-by-analogy is used. This is based on the principle that if an animal responds to a stimulus in a similar way to ourselves, it is likely to have had an analogous experience.

A definition of "pain" widely accepted by scientific investigators is "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage".[24]


Nociception: The reflex arc of a dog with a pin in her paw. Note there is no communication to the brain, but the paw is withdrawn by nervous impulses generated by the spinal cord. There is no conscious interpretation of the stimulus by the dog.

Nociception has been defined as "the detection of stimuli that are injurious or would be if sustained or repeated".[37] It initiates immediate withdrawal of limbs or appendages, or the entire body, and therefore has clear adaptive advantages. Nociception usually involves the transmission of a signal along a chain of nerve fibers from the site of a noxious stimulus at the periphery to the spinal cord and brain. In vertebrates, this process evokes a reflex arc response generated at the spinal cord and not involving the brain, such as flinching or withdrawal of a limb. Nociception is found, in one form or another, across all major animal taxa.[36] Nociception can be observed using modern imaging techniques; and a physiological and behavioral response to nociception can be detected.

Emotional pain[edit]

Sometimes a distinction is made between "physical pain" and "emotional" or "psychological pain". Emotional pain is the pain experienced in the absence of physical trauma, e.g. the pain experienced by humans after the loss of a loved one, or the break-up of a relationship. It has been argued that only primates and humans can feel "emotional pain", because they are the only animals that have a neocortex – a part of the brain's cortex considered to be the "thinking area". However, research has provided evidence that monkeys, dogs, cats and birds can show signs of emotional pain and display behaviours associated with depression during painful experience, i.e. lack of motivation, lethargy, anorexia, unresponsiveness to other animals.[12]

Physical pain[edit]

A definition of pain widely accepted and used by scientists is "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage".[37] The nerve impulses of the nociception response may be conducted to the brain thereby registering the location, intensity, quality and unpleasantness of the stimulus. This subjective component of pain involves conscious awareness of both the sensation and the unpleasantness (the aversive, negative affect). The brain processes underlying conscious awareness of the unpleasantness (suffering), are not well understood.

There have been several published lists of criteria for establishing whether non-human animals are capable of perceiving pain, e.g.[24][38] Some criteria that may indicate the potential of another species, including cephalopods, to feel pain include:[38]

  1. Has a suitable nervous system and sensory receptors
  2. Has opioid receptors and shows reduced responses to noxious stimuli when given analgesics and local anaesthetics
  3. Physiological changes to noxious stimuli
  4. Displays protective motor reactions that might include reduced use of an affected area such as limping, rubbing, holding or autotomy
  5. Shows avoidance learning
  6. Shows trade-offs between noxious stimulus avoidance and other motivational requirements
  7. High cognitive ability and sentience

Research findings[edit]

Peripheral nervous system[edit]

A moving octopus. Note the co-ordination of the arms.

A science-based report from the University of British Columbia to the Canadian Federal Government has been quoted as stating "The cephalopods, including octopus and squid, have a remarkably well developed nervous system and may well be capable of experiencing pain and suffering."[39]


The discovery of nociceptors in cephalopods has occurred relatively recently. In 2011, it was written that nociceptors had yet to be described in any cephalopod.[37] However, in 2013, nociceptors responsive to mechanical and electrical stimuli, but not thermal stimuli, were described in the longfin inshore squid (Doryteuthis pealeii)[40] (note - it is highly unlikely that squid encounter temperatures greater than 30°C making it very improbable that the nervous system will have evolved nociceptors to detect such high temperatures.[41]) This study also provided evidence that these receptors, as in vertebrates, undergo both short-term and long-term sensitization (30 min and 24 h, respectively).[5][42] Similarly, low-threshold mechanoreceptors and cells considered to be nociceptors in the algae octopus (Abdopus aculeatus) are sensitised for at least 24 hrs after a crushing injury.[43]

Nerve fibres[edit]

Both the arms and the mantle contain nervous tissue that conduct nociceptive information to the higher processing areas of the CNS.[43]

Numerous studies have described the existence of neural tissue paths that connects the peripheral areas of cephalopods to their CNS. However it is unclear if specific pain pathways are among these.[42]

In octopuses, the large optic lobes and the arms' nervous system are located outside the brain complex. The optic lobes contain 120 to 180 million neurons and the nervous system of the arms contains two-thirds of the total 500 million neurons in the nervous system.[37] [44]


The octopus central brain contains 40 to 45 million cells. The brain-to-body mass ratio of the octopus is the highest of all the invertebrates and larger than that of most fish and reptiles (i.e. vertebrates). However, scientists have noted that brain size is not necessarily related to the complexity of its function.[45][46]

Octopuses have centralized brains located inside a cartilaginous capsule surrounding the oesophagus. It is divided into approximately 40 specialized areas and lobes that are arranged hierarchically; these include the sub- and supra-oesophageal masses, and the magnocellular, buccal, inferior frontal, vertical, basal, optic, peduncle, and olfactory lobes. The lobe's functions include learning, memory, processing information from the various sensory modalities, control of motor responses and the blood system. The vertical and frontal lobe complexes, unique among invertebrates, have vertebrate-like properties and are dedicated to learning and memory.[47][37][44][48][49][42] It has been suggested the vertical lobe system processes information related to pain.[7]

The nautilus brain lacks the vertical lobe complex and is therefore simpler than that of the coleoids,[50] however, they still exhibit rapid learning (within 10 trials), and have both short- and long-term memory (as found in operant studies of cuttlefish).[50]

In 2011, it was written that it was not known where in the brain cephalopods process nociceptive information meaning that evidence for nociception is exclusively behavioural.[37]

Opioid system[edit]

The four main opioid receptor types (delta, kappa, mu, and NOP) are found in vertebrates; hey are highly conserved in this taxon and are found even in primitive jawless fishes. The endogenous system of opioid receptors is well known for its analgesic potential in vertebrates. Enkephalins come in two forms, met-enkephalin and leu-enkephalin, which are involved in regulating nociception in the vertebrate body as they bind to the body's opioid receptors.

Enkephalin-like peptides have been found in neurones of the palliovisceral lobe of the brain in the common octopus, and met-enkephalin receptors as well as delta opioid receptors in the mantle, arms, gut and vena cava of various octopus species. Leu-enkephalin and delta receptors have been found in the mantle, arms and other tissues in Amphioctopus fangsiao.[51][52]

Although cephalopods appear to have an opiod system, it has been noted that in vertebrates, the opioid system has a wide range of complex functions meaning the presence of an opioid system in cephalopods (and other invertebrates) is not necessarily evidence of this having an antinociceptive function.[42]

Effects of naloxone[edit]

Naloxone is an μ-opioid receptor antagonist which, in vertebrates and some other invertebrates, negates the effects of opioids. The substance has a similar reversal effect in the California two-spot octopus (Octopus bimaculatus).[53]

Effects of analgesics and anaesthetics[edit]

Cephalopod veterinary medicine sometimes uses the same analgesics and anaesthetics used in mammals and other vertebrates, although in 2015, it was stated "there are no specific studies about the effect of analgesics in cephalopods".[42]

If anaesthetic (1% ethanol and MgCl2) is administered prior to a crushing injury, this prevents nociceptive sensitisation.[54]

General anaesthesia in cephalopods has been achieved with a large range of substances, including isoflurane.[5][55] Benzocaine is considered to be an effective anaesthetic for the giant Pacific octopus (Enteroctopus dofleini).[56] Magnesium hydrochloride, clove oil, carbon dioxide and ethanol are among the substances used for anaesthesia of cephalopods, however, their effectiveness and potency are still under-researched.[42]

Physiological responses[edit]

The physiological responses of cephalopods to noxious stimuli include cardio-respiratory changes, defecation and vomiting.[42]

Behavioural responses[edit]


Many animals, including some octopuses, autotomise limbs when these are injured. This is considered to be a nociceptive behaviour. After receiving a crushing injury to an arm, algae octopuses autotomise the affected arm and show wound protective behaviours such as wrapping other arms around the wounded arm. These protective responses continue for at least 24 hours. In the long-term, they also show heightened sensitisation at the site of the injury and a reduced threshold to showing escape responses.[43][41] The curled octopus (Eledone cirrhosa) also shows protective responses to injury.[57][58] These long-term changes in behaviour suggest that "... some molluscs may be capable not only of nociception and nociceptive sensitization but also of neural states that have some functional similarities to emotional states associated with pain in humans."[37]

Other immediate defensive behaviours that might indicate a perception of pain include inking, jetting locomotion and dymantic display.[58]

In one study, squid did not appear to show increased attention to areas of their body that have been injured.[24]

Avoidance learning[edit]

Avoidance learning in octopuses has been known since 1905.[59] Noxious stimuli, for example electric shocks, have been used as "negative reinforcers" for training octpuses, squid and cuttlefish in discrimination studies and other learning paradigms.[60][37] Repeated exposure to noxious stimuli can have long-term effects on behaviour. It has been shown that in octopuses, electric shocks can be used to develop a passive avoidance response leading to the cessation of attacking a red ball.[59]

As in vertebrates, longfin inshore squid show sensitization of avoidance responses to tactile and visual stimuli associated with a peripheral noxious stimulus. This persists for at least 48 hours after injury, indicating that behavioural responses to injury in cephalopods can be similar to those in vertebrates.[37]

Trade-offs in motivation[edit]

Octopuses show trade-offs in their motivation to avoid being stung by sea anemones. Octopuses frequently predate hermit crabs, however, they change their hunting strategy when the crabs place an anemone on their shell as protection. Octopuses attempt various different methods such as using only a single arm, moving below the anemone or blowing jets of water at it. The trade-off is that they attempt to avoid the anemone stings by using methods that are less effective than they would usually use for predating the hermit crab.[46]

Injured squid show trade-offs in motivation due to injury, for example, they use crypsis rather than escape behaviour when reacting to a visual threat. The same study showed that injured squid begin escape responses earlier and continue these for longer for up to 48 hours after injury.[61]

In 2014, the adaptive value of sensitisation due to injury was tested using the predatory interactions between longfin inshore squid and black sea bass (Centropristis striata) which are natural predators of this squid. If injured squid are targeted by a bass, they began their defensive behaviours sooner (indicated by greater alert distances and longer flight initiation distances) than uninjured squid. If anaesthetic (1% ethanol and MgCl2) is administered prior to the injury, this prevents the nociceptive hypersensitisation and blocks the effect. This study has wide implications because both long-term sensitisation and pain are often considered to be maladaptive rather than adaptive; the authors claim this study is the first evidence to support the argument that nociceptive sensitisation is actually an adaptive response to injuries.[54]

Cognitive ability and sentience[edit]

It has been argued that although a higher cognitive capacity in some animals may indicate a greater likelihood of them being able to perceive pain, it also gives these animals a greater ability to deal with this, leaving animals with a lower cognitive ability a greater problem in coping with pain.[62][63]

Cephalopods can demonstrably benefit from environmental enrichment[64] indicating behavioural and neuronal plasticity not exhibited by many other invertebrates.

Tool use[edit]

A veiled octopus travelling with shells it has collected for protection

Octopuses are widely reported as examples of an invertebrate that exhibits flexibility in tool use. For example, veined octopuses (Amphioctopus marginatus) retrieve discarded coconut shells, manipulate them, transport them some distance, and then re-assemble them to use as a shelter.[65]


The learning abilities of cephalopods demonstrated in a range of studies indicate advanced cognitive abilities.

Octopuses are capable of reversal learning, a form of advanced learning demonstrated by vertebrates such as rats.[66] Giant Pacific octopuses are able to recognise individual humans[67] and common octopuses can recognise other octopus individuals for at least one day.[4]

In a study on social learning, common octopuses (observers) were allowed to watch other octopuses (demonstrators) select one of two objects that differed only in colour. Subsequently, the observers consistently selected the same object as did the demonstrators.[68]

Both octopuses and nautiluses are capable of vertebrate-like spatial learning.[37]

Pavlovian conditioning has been used to train chambered nautiluses (Nautilus pompilius) to expect being given food when a bright blue light flashed. The research revealed that nautiluses had memory capabilities akin to the "short-term" and "long-term memories" of the Coleoidea. This is despite very different brain structures. However, the long-term memory capability of nautiluses is much shorter than that of Coleoidea. Nautiluses appear to completely forget training they received 24 hours later, whereas octopuses remain conditioned for several weeks.[69][70][71][66]

Body patterns of the common cuttlefish[1]
Acute Chronic
uniform blanching uniform darkening acute disruptive flamboyant deimatic intense zebra passing cloud
uniform light stipple light mottle dark mottle disruptive weak zebra

Criteria for pain perception[edit]

Scientists have proposed that in conjunction with argument-by-analogy, criteria of physiology or behavioural responses can be used to assess the possibility that non-human animals can perceive pain.[24] In 2015, Lynne Sneddon, Director of Bioveterinary Science at the University of Liverpool, published a review of the evidence gathered investigating the suggestion that cephalopods can experience pain.[41] The review included the following summary table -

Criteria for pain perception in non-human animals[41]








Nociceptors Green tickY Green tickY Green tickY Green tickY
Pathways to CNS Green tickY Green tickY Green tickY Green tickY
Central processing to CNS Green tickY Green tickY Green tickY Green tickY
Receptors for analgesic drugs Green tickY Green tickY Green tickY Green tickY
Physiological responses Green tickY Green tickY Green tickY Green tickY
Movement away from noxious stimuli Green tickY Green tickY Green tickY Green tickY
Abnormal behavioural changes Green tickY Green tickY Green tickY Green tickY
Protective behaviour Green tickY Green tickY Green tickY Green tickY
Responses reduced by analgesic drugs Green tickY Green tickY Green tickY Green tickY
Self-administration of analgesia Green tickY Green tickY not yet not yet
Responses with high priority over other stimuli Green tickY Green tickY Green tickY Green tickY
Paying a cost to access analgesia Green tickY Green tickY not yet not yet
Altered behavioural choices/preferences Green tickY Green tickY Green tickY Green tickY
Rubbing, limping or guarding Green tickY Green tickY Green tickY Green tickY
Paying a cost to avoid stimulus Green tickY Green tickY not yet Green tickY
Trade-offs with other requirements Green tickY Green tickY not yet Green tickY

In the table, Green tickY indicates positive evidence and not yet denotes it has not been tested or there is insufficient evidence.

Note: recent evidence[54][61][46] indicates that cephalopods exhibit "trade-offs with other requirements" which Sneddon might not have been aware of.

Societal implications[edit]

Sannakji is a dish of live baby octopuses eaten while still squirming on the plate.

Some cephalopods are widely used food sources. In some countries, octopus is eaten live. Sannakji is a type of hoe, or raw dish, in Korea. It consists of live baby octopuses (nakji), either whole, or cut into small pieces and immediately served. The dish is eaten while the octopuses are still squirming on the plate.[72]

Cephalopods are caught by nets, pots, traps, trawling and hand jigging. Sometimes, the devices are left in situ for several days thereby preventing feeding and provoking the trapped animals to fight with each other, potentially causing suffering from discomfort and stress.

Other societal implications of cephalopods being able to perceive pain include acute and chronic exposure to pollutants, aquaculture, removal from water for routine husbandry, pain during slaughter and during scientific research.

Given the possibility that cephalopods can perceive pain, it has been suggested that precautionary principles should be applied during their interactions with humans and the consequences of our actions.[58]

Protective legislation[edit]

In addition to vertebrate animals including cyclostomes, cephalopods should also be included in the scope of this Directive, as there is scientific evidence of their ability to experience pain, suffering, distress and lasting harm. (emphasis added)

In most legislation to protect animals, only vertebrates are protected. However, cephalopods have a special position among invertebrates in terms of their perceived ability to experience pain, which is reflected in some national and international legislation.[35]

  • In the UK, the legislation protecting animals during scientific research, the "Animals (Scientific Procedures) Act 1986" (ASPA), protects cephalopods from the moment they become capable of independent feeding.[73] The legislation protecting animals in most other circumstances in the UK is "The Animal Welfare Act, 2006" which states that "...animal means a vertebrate other than man..." thereby excluding cephalopods.[74]
  • The Canadian Council on Animal Care (CCAC) differentiates between "invertebrates" which are classified on a tier of lowest concern with respect to invasive procedures and "cephalopods and other higher invertebrates".[75]
  • New Zealand's "Animal Welfare Act 1999", as of November 2015[13] protects octopus and squid (but apparently not cuttlefish and nautiluses).
  • The EU's laboratory animal welfare EU Directive 2010/63/EU[76] implemented in 2013 protects all cephalopods, but stops short of protecting any other invertebrates, despite initially considering crustaceans.[75]

In the US, the legislation protecting animals during scientific research is the "Animal Welfare Act of 1966". This Act excludes protection of "cold-blooded" animals, thereby also excluding cephalopods.[77] Protection in Australia and the US is not national and instead is limited to institution specific guidelines.[78] The 1974 Norwegian Animal Rights Law states it relates to mammals, birds, frogs, salamander, reptiles, fish, and crustaceans, i.e. it does not include cephalopods.[79]


There is controversy about whether cephalopods have the capability to experience pain. This mainly relates to differences between the nervous systems of different taxa. Reviews have been published arguing that fish cannot feel pain because they lack a neocortex in the brain.[80][81] If true, this would also rule out pain perception in most mammals, all birds, reptiles[82] and cephalopods. However, the Cambridge Declaration on Consciousness published in 2012, states that the absence of a neocortex does not appear to preclude an organism from experiencing affective states.[16]

In 1991, it was stated that "Although the evidence for pain perception is equivocal..." "...the evidence certainly does not preclude the possibility of pain in these animals [cephalopods] and, moreover, suggests that pain is more likely in cephalopods than in the other invertebrates with less ‘complex’ nervous organizations...".[83]

See also[edit]

Further reading[edit]

  • Zarrella, I., Ponte, G., Baldascino, E. and Fiorito, G. (2015). Learning and memory in Octopus vulgaris: a case of biological plasticity. Current Opinion in Neurobiology, 35, 74-79.


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The kype is the hook on the lower jaw which some salmonids develop before the breeding season

The kype is a hook-like structure which develops at the distal tip of the lower jaw in some male salmonids prior to the spawning season.[1] The structure usually develops in the weeks prior to, and during migration to the spawning grounds. In addition to the development of the kype, a large depression forms in the two halves of the premaxilla in the upper jaw allowing the kype to fit into this when the mouth is closed.[2]

The kype functions as a secondary sexual characteristic and influences the formation of dominance hierarchies at the spawning grounds. The size of the kype is believed to determine male spawning frequency.


The kype is, in part, composed of rapidly growing skeletal needles arising at the tip of the dentary (the anterior and largest of the bones making up the lower jaw), which itself is composed of compact bone. Proximally, the needles connect together into a mesh-work which retains connective tissue inside bone marrow spaces. Ventrally, the needles blend into Sharpey-fibre bone. Rapid formation of the skeleton of the kype is apparent due to the presence of numerous osteoblasts and the appearance of proteoglycans at the growth zone. Unlike the normal compact bone of the dentary, the new skeletal tissue contains chondrocytes and cartilage.[2][3] The mode of bone formation in the kype has been described as "making bone as fast as possible and with as little material as possible".[3]

Some species of salmon are semelparous (they have a single reproductive bout before death) whereas others are iteroparous (they spawn multiple times after maturation). In iteroparous cases, at least in Atlantic salmon, the kype is not fully resorbed after the breeding season, although basal parts of the kype skeleton are re-modelled into regular dentary bone.[2] In some cases, especially with large brown trout, the fish never lose their kype. Instead, as they re-enter subsequent spawning seasons, their kypes continue to grow larger. This fast growing skeletal tissue fuses with the dense dentary, leading to a permanent kype that continues to grow in size.[4]


A large male arctic char in spawning condition with a clearly visible kype.

Brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss), many other male trout and salmon develop a kype prior to spawning periods.[4] In pre-spawning Salmo and Salvelinus males, the lower jaw elongates and the hook develops; female salmon do not develop a kype.[2] Bull trout (Salvelinus confluentus) are adfluvial (adults spawn in streams but subadults and adults migrate to lakes for feeding) and sometimes develop a kype, however, although this may occur in some populations, it remains absent in others.[5]

Among American species of Salvelinus, or charr, the kype reaches its maximum size in the large anadromous males, Dolly Varden trout (Salvelinus malma) and Brook trout (Salvelinus fontinalis), whereas it is hardly discernible or absent in large nonanadromous males, Arctic char (Salvelinus alpinus) and Lake trout (Salvelinus namaycush).[6]

Similar structural changes[edit]

In salmonids of the genus Oncorhynchus (meaning "hooked snout"), the upper jaw elongates more than the lower jaw to form a "snout".[2] In some species, the development of the "kype" (in this study defined as the distance from the middle of eye to the tip of the snout) is used as an indicator of a difference in behavioural mating strategies. Chinook salmon (Oncorhynchus tshawytscha) express one of two fixed alternative reproductive tactics. Individuals expressing these are referred to as "hooknose" or "jack". Hooknose males leave their natal rivers at the end of their first year of life, but then return after maturing for 3 to 5 years on average. Once returned, they fight for position in a dominance hierarchy to gain closer access to spawning females. Alternatively, jacks are presumably resident in their natal rivers their entire lives, reach sexual maturity precociously (after 2 years), and use a sneaking tactic, by darting from nearby refuges to steal fertilisations from hooknose males.[7]

Associated seasonal changes[edit]

Sockeye salmon (Oncorhynchus nerka)
Female (above) and male in mating condition. Note the male has a kype, enlarged snout, humped back and deeper, more extensive colouration

Development of the kype often occurs in association with other seasonal changes. In the Atlantic salmon (Salmo salar), kype development is accompanied by a morphogenesis of bones and cartilages in the ethmoidal zone (the anterior region of the skull) changing the appearance of both jaws, the appearance of "breeding teeth" and resorption of scales (more so in males than females).[8] Some salmonids may develop a predominant hump under their dorsal fin.


Charles Darwin considered the kype to be a product of sexual selection and as a tool for fighting among males. Others have suggested it has no function, and observed the kype seems to prevent the use of the breeding teeth which sometimes develop alongside the kype. One suggestion was that the kype is merely the result of a surplus of chemicals, not used for the production of sex products.[2]

More recently, the kype is regarded as a secondary sex characteristic displayed by males at the spawning grounds. Therefore, its function is considered to be helping the fish establish a hierarchy among other males where those with larger kypes are dominant over animals with smaller kypes,[9][2] and/or characteristics that could be of importance in inter- and intra-sexual evaluations of individual quality. The size of the kype is believed to determine male spawning frequency.[10]

In extinct salmon[edit]

The extinct salmon, Oncorhynchus rastrosus, was first named for its incredible premaxillary dentition. It possesses an enormous conical tooth on each premaxilla. There is no visible kype on the dentary, implying a different strategy for forming mate dominance.[11]



  1. ^ "Kype". FishBase. Retrieved April 26, 2016.
  2. ^ a b c d e f g Witten, P.E. and Hall, B.K. (2003). "Seasonal changes in the lower jaw skeleton in male Atlantic salmon (Salmo salar L.): remodelling and regression of the kype after spawning". Journal of Anatomy. 203 (5): 435–450.
  3. ^ a b Witten, P.E. and Hall, B.K. (2002). "Differentiation and growth of kype skeletal tissues in anadromous male Atlantic salmon (Salmo salar)". International Journal of Developmental Biology. 46 (5): 719–730.
  4. ^ a b Paetz, D. (March 19, 2015). "What is a kype on a fish and why does it exist anyway?". Retrieved April 26, 2016.
  5. ^ Nitychoruk, J. M., Gutowsky, L.F.G., Harrison, P.M., Hossie, T.J., Power, M. and Cooke, S.J. (2013). "Sexual and seasonal dimorphism in adult adfluvial bull trout (Salvelinus confluentus)". Canadian Journal of Zoology. 91 (7): 480–488.
  6. ^ Morton, W.M. (1965). "The taxonomic significance of the kype in American salmonids". Copeia. 1965 (1): 14–19.
  7. ^ Butts, I.A., Love, O.P., Farwell, M. and Pitcher, T.E. (2012). "Primary and secondary sexual characters in alternative reproductive tactics of Chinook salmon: Associations with androgens and the maturation-inducing steroid". General and Comparative Endocrinology. 175 (3): 449–456.
  8. ^ Kacem, A., Baglinière, J.L. and Meunier, F.J. (2013). "Resorption of scales in Atlantic salmon (Salmo salar) during its anadromous migration: a quantitative study". Cybium. 37 (3): 199–206.
  9. ^ Järvi, T. (1990). "The effects of male dominance, secondary sexual characteristics and female mate choice on the mating success of male Atlantic salmon Salmo salar". Ethology. 84 (2): 123–132.
  10. ^ Haugland, T., Rudolfsen, G., Figenschou, L. and Folstad, I. (2011). "Is the adipose fin and the lower jaw (kype) related to social dominance in male Arctic charr Salvelinus alpinus?". Journal of Fish Biology. 79 (4): 1076–1083.
  11. ^ Claeson, K.M., Davis, E.B., Sidlauskas, B.L. and Prescott, Z.M. (2016). "The Sabertooth Salmon, Oncorhynchus rastrosus, gets a facelift". Philadelphia College of Osteopathic Medicine.


Intelligent corvid

Theory of mind in animals (ToM), sometimes known as mentalisation or mind-reading,[1] is the ability of nonhuman animals to attribute mental states (e.g. intents, desires, pretending, knowledge) to themselves and others, and to understand that others have mental states that are different from their own. As originally defined, it enables us to understand that mental states can be the cause of, and therefore be used to explain and predict, the behaviour of others.[2] Empathy is a closely related concept, meaning the recognition and understanding of the states of mind of others, including their beliefs, desires and particularly emotions. This is often characterised as the ability to "put oneself into another's shoes".

Theory of mind in animals is controversial. On the one hand, one hypothesis proposes that some animals have complex cognitive processes which allow them to attribute mental states to other individuals; in other words, they are mind-reading. A second, more parsimonious, hypothesis proposes that these skills depend on more simple learning processes such as associative learning;[3] in other words, they are behaviour-reading.

Several studies have been designed specifically to test theory of mind, using interspecific or intraspecific communication.

Several taxa have been tested including primates, birds and canines. Positive results have been found, however, these are often qualified as showing only low-grade ToM, or rejected as convincing by other researchers in the subject.

History and development[edit]

Much of the early work on ToM in animals focused on the understanding chimpanzees have of human knowledge

The term "Theory of Mind" was originally proposed[2] by Premack and Woodruff in 1978.[4] Early pioneering work was almost exclusively limited to investigation of chimpanzees understanding the knowledge of humans. However, this approach was not particularly fruitful and 20 years later, Heyes, reviewing all the extant data on primate ToM, observed that there had been "no substantial progress" in the subject area.[5]

In 2000, a landmark paper was published[6] which approached the issue differently by examining competitive foraging behaviour between conspecific (members of the same species) primates. This led to the (rather limited) conclusion that "chimpanzees know what conspecifics do and do not see".[7]

On the basis of studies of brain activity in higher primates, it was proposed in 2003 that the ToM system is composed of three major nodes, the medial prefrontal, superior temporal sulcus, and inferior frontal. It was further proposed that the medial prefrontal node maintains representations of the mental state of the self, that the superior temporal sulcus detects the behaviour of other animals and analyzes the goals and outcomes of this behaviour, and that the inferior frontal region maintains representations of actions and goals.[8]

In 2007, Penn and Povinelli wrote "...there is still little consensus on whether or not nonhuman animals understand anything about unobservable mental states or even what it would mean for a non-verbal animal to understand the concept of a ‘mental state’." They went on further to suggest that ToM was "...any cognitive system, whether theory-like or not, that predicts or explains the behaviour of another agent by postulating that unobservable inner states particular to the cognitive perspective of that agent causally modulate that agent's behaviour".[9]

In 2010, an article in Scientific American acknowledged that dogs are considerably better at using social direction cues (e.g. pointing by humans) than are chimpanzees.[10] In the same year, Towner wrote, "...the issue may have evolved beyond whether or not there is theory of mind in non-human primates to a more sophisticated appreciation that the concept of mind has many facets and some of these may exist in non-human primates while others may not."[4] Horowitz, working with dogs, agreed with this and suggested that her recent results and previous findings called for the introduction of an intermediate stage of ability, a rudimentary theory of mind, to describe animals' performance.[11]

In 2013, Whiten reviewed the literature and concluded that regarding the question "Are chimpanzees truly mentalists, like we are?", he stated he could not offer an affirmative or negative answer.[7] A similarly equivocal view was stated in 2014 by Brauer, who suggested that many previous experiments on ToM could be explained by the animals possessing other abilities. They went on further to make reference to several authors who suggest it is pointless to ask a "yes or no" question, rather, it makes more sense to ask which psychological states animals understand and to what extent.[12] At the same time, it was suggested that a "minimal theory of mind" may be "what enables those with limited cognitive resources or little conceptual sophistication, such as infants, chimpanzees, scrub-jays and human adults under load, to track others' perceptions, knowledge states and beliefs."[13]

In 2015, Cecilia Heyes, Professor of Psychology at the University of Oxford, wrote about research on ToM, "Since that time [2000], many enthusiasts have become sceptics, empirical methods have become more limited, and it is no longer clear what research on animal mindreading is trying to find" and "However, after some 35 years of research on mindreading in animals, there is still nothing resembling a consensus about whether any animal can ascribe any mental state" (Heyes' emphasis). Heyes further suggested that "In combination with the use of inanimate control stimuli, species that are unlikely to be capable of mindreading, and the ‘goggles method’ [see below], these approaches could restore both vigour and rigour to research on animal mindreading."[1]


Specific categories of behaviour are sometimes used as evidence of animal ToM, including imitation, self-recognition, social relationships, deception, role-taking (empathy), perspective-taking, teaching and co-operation,[4], however, this approach has been criticised.[5] Some researchers focus on animals' understanding of intention, gaze, perspective, or knowledge, i.e. what another being has seen. Several experimental methods have been developed which are widely used or suggested as appropriate tests for nonhuman animals possessing ToM. Some studies look at communication between individuals of the same species (intraspecific) whereas others investigate behaviour between individuals of different species (interspecific).


The Knower-Guesser method has been used in many studies relating to animal ToM. Animals are tested in a two-stage procedure. At the beginning of each trial in the first discrimination training stage, an animal is in a room with two humans. One human, designated the “Guesser,” leaves the room, and the other, the “Knower,” baits one of several containers. The containers are screened so that the animal can see who does the baiting, but not where the food has been placed. After baiting, the Guesser returns to the room, the screen is removed, and each human points directly at a container. The Knower points at the baited container, and the Guesser at one of the other three, chosen at random. The animal is allowed to search one container and to keep the food if it is found.[5]

Competitive feeding paradigm[edit]

The competitive feeding paradigm approach is considered by some as evidence that animals have some understanding of the relationship between "seeing" and "knowing".[1]

At the beginning of each trial in the paradigm, a subordinate animal and a dominant animal (the putative target of mind-reading) are confined on opposite sides of an enclosure containing two visual barriers. In all trials, a human observer enters the enclosure and places food on the subordinate’s side of one of the visual barriers (one baiting event), and in some trials the observer re-enters the enclosure 5–10 s later and moves the food to the subordinate’s side of the other visual barrier (second baiting event). In all conditions, the door to the subordinate’s cage is open during the baiting by the observer. The conditions vary according to whether the dominant’s door is open or closed, and therefore whether the subordinate can see the dominant during the baiting events. After baiting, both of the animals are released into the enclosure, with the subordinate being given a head start. If the animals posses ToM, it is expected that subordinates are more likely to secure the food, and less likely to refrain from approaching it, when (1) the dominant’s door is closed rather than open during trials with a single baiting event, and (2) in trials where there are two baiting events and the dominant’s door, although open during the first, was closed during the second baiting event, and, (3) in trials where there is a single baiting event with the dominant’s door open, subordinates are more likely to get the food when they compete at the end of the trial with a different dominant individual than the one who witnessed the baiting.

The Goggles Method[edit]

In one suggested protocol, chimpanzees are given first-hand experience of wearing two mirrored visors. One of the visors is transparent whereas the other is not. The visors themselves are of markedly different colours or shapes. During the subsequent test session, the chimpanzees are given the opportunity to use their species-typical begging behaviour to request food from one of the two humans, one wearing the transparent visor and the other wearing the opaque. If chimpanzees possess ToM, it would be expected they would beg more often from the human wearing the transparent visor.

In nonhuman primates[edit]

Many ToM studies have used nonhuman pimates (NHPs). One study that examined the understanding of intention in orangutans (Pongo pygmaeus), chimpanzees (Pan troglodytes) and children showed that all three species understood the difference between accidental and intentional acts.[14]


There is controversy over the interpretation of evidence purporting to show ToM in chimpanzees.[15]

William Field and Sue Savage-Rumbaugh have no doubt that bonobos have evolved ToM and cite their communications with a well-known captive bonobo (Pan paniscus), Kanzi, as evidence.[16]

However, empirical studies show that chimpanzees are unable to follow a human’s gaze,[17] and are unable to use other human-eye information.[18][19] Attempts to use the "Goggles Method" (see above) on highly human-enculturated chimpanzees, failed to demonstrate they posses ToM.[9]

In contrast, chimpanzees use the gaze of other chimpanzees to gain information about whether food is accessible.[6] Subordinate chimpanzees are able to use the knowledge state of dominant chimpanzees to determine which container has hidden food.[20]

If chimpanzees can see two opaque boards on a table and are expecting to find food, they do not choose a board lying flat because if food was under there, it would not be lying flat. Rather, they choose a slanted board, presumably inferring that food underneath is causing the slant. Chimpanzees appear able to know that other chimpanzees in the same situation make a similar inference. In a foraging game, when their competitor had chosen before them, chimpanzees avoided the slanted board on the assumption that the competitor had already chosen it.[21] In a similar study, chimps were provided with a preference box with two compartments, one containing a picture of food, he other containing a picture of nothing (the pictures had no causal relation to the contents). In a foraging competition game, chimpanzees avoided the chamber with the picture of food when their competitor had chosen one of the chambers before them. The authors suggested this was presumably on the assumption that the competitor shared their own preference for it and had already chosen it.[22]

One study tested another sensory mode of ToM. In a chimpanzee-human food competition, the human sat inside a booth, with one piece of food to their left and one to their right, which they could withdraw from the chimpanzee competitor’s reach as needed. In the first experiment, the chimpanzee could approach either side of the booth unseen by the human, but then had to reach through either a clear or opaque tunnel to get the food. In a second experiment, both tunnels were clear and the human was looking away, but one of the tunnels made a loud noise when it was opened. Chimpanzees reached through the opaque tunnel in the first experiment and the silent tunnel in the second. This meant they successfully concealed their food-stealing from the human competitor in both cases and actively manipulated both the visual and auditory perception of humans by concealing information from them.[23]

Other primates[edit]

Rhesus macaques selectively steal grapes from humans who are incapable of seeing the grape compared to humans who can see the grape.

In one approach testing monkeys, rhesus macaques (Macaca mulatta) are able to “steal” a contested grape from one of two human competitors. In six experiments, the macaques selectively stole the grape from a human who was incapable of seeing the grape, rather than from the human who was visually aware. The authors suggest that rhesus macaques possess an essential component of ToM: the ability to deduce what others perceive on the basis of where they are looking.[24] Similarly, free ranging rhesus macaques preferentially choose to steal food items from locations where they can be less easily observed by humans, or where they will make less noise.[7]

A comparative psychology approach tested six species of captive NHPs (three species of great apes: orangutans, gorillas, chimpanzees, and three species of old-world monkeys: lion-tailed macaques (Macaca silenus), rhesus macaques and collared mangabeys (Cercocebus torquatus)) in a “hide and seek” game in which the NHPs played against a human opponent. In each trial, the NHP has to infer where food has been hidden (either in their right or left hand) by the human opponent. In general, the NHPs failed the test (whereas humans did not), but surprisingly, performances between the NHP species did not reveal any inter-species differences. The authors also reported that at least one individual of each of the species showed (weak) evidence of ToM.[25]

In 2009, a summary of the ToM research, particularly emphasising an extensive comparison of humans, chimpanzees and orang-utans,[26] concluded that great apes do not exhibit understanding of human referential intentions expressed in communicative gestures, such as pointing.[27]

In birds[edit]


Ravens adjust their caching behaviour according to whether they have been watched and who was watching them.

Ravens are members of the corvidae family and are widely regarded as having complex cognitive abilities.[28]

Food-storing ravens cache (hoard) their food and pilfer (steal) from other ravens' caches. They protect their caches from being pilfered by conspecifics using aggression, dominance and re-caching. In both the wild and in captivity, potential pilferers rarely approach caches until the storers have left the cache vicinity. When storers are experimentally prevented from leaving the vicinity of the cache, pilferers first search at places other than the cache sites. When ravens (Corvus corax) witness a conspecific making caches, to pilfer those caches, either in private or together with the storer, they (1) delay approaching the cache only when in the presence of the storer, and (2) also quickly engage in searching away from the caches when together with dominant storers. These behaviours raise the possibility that ravens are capable of withholding their intentions, and also providing false information to avoid provoking the storer's aggression to protect its cache. Ravens selectively alter their pilfering behaviour when the storers are likely to defend the caches, thereby supporting the interpretation that they are deceptively manipulating the others’ behaviour.[29] Other studies indicate that ravens recall whom was watching them during caching, but also know the effects of visual barriers on what competitors can and can not see, and how this affects their pilfering.[30]

Ravens have been tested for their understanding of "seeing" as a mental state in other ravens. It appears they take into account the visual access of other ravens, even when they cannot see the other raven.[31]

In one study, ravens were tested in two rooms separated by a wooden wall. The wall had two functional windows that could be closed with covers; each cover had a peephole drilled into it. In the next familiarization step, the ravens are trained to use a peephole to observe and pilfer human-made caches in the adjacent room. Under test conditions, there was no other raven present in the adjacent room, however, a hidden loudspeaker played a series of sounds recorded from a competitor raven. The storing raven generalized from their own experience when using the peephole to pilfer the human-made caches and predicted that the audible (raven) competitors could potentially see their caches through the peep-hole and took appropriate action, i.e. the storing ravens finished their caches more quickly and they returned to improve their caches less often. The researchers pointed out that this represented "seeing" in a way that cannot be reduced to the tracking of gaze cues - a criticism leveled at many other studies of ToM.[32] The researchers further suggested that their findings could be considered in terms of the "minimal" (as opposed to "full-blown") ToM recently suggested.[13]

Using the Knower-Guesser approach, ravens observing a human hiding food are capable of predicting the behaviour of bystander ravens that had been visible at both, none or just one of two baiting events. The visual field of the competitors was manipulated independently of the view of the test-raven. The findings indicate that ravens not only remember whom they have seen at caching but they also take into account that the other raven's view was blocked.[33]

Scrub jays[edit]

Western scrub jays may show evidence of possessing theory of mind

Scrub jays are also corvids. Western scrub jays (Aphelocoma californica) both cache food and pilfer other scrub jays' caches. They use a range of tactics to minimise the possibility that their own caches will be pilfered. One of these tactics is to remember which individual scrub jay watched them during particular caching events and adjust their re-caching behaviour accordingly.[34] One study with particularly interesting results found that only scrub jays which had themselves pilfered would re-cache when they had been observed making the initial cache.[28] This has been interpreted as the re-caching bird projecting its own experiences of pilfering intent onto those of another potential pilferer, and taking appropriate action.[7] Another tactic used by scrub jays is if they are observed caching, they re-cache their food when they are subsequently in private. In a computer modeling study using "virtual birds", it was suggested that re-caching is not motivated by a deliberate effort to protect specific caches from pilfering, but by a general motivation to simply cache more. This motivation is brought on by stress, which is affected by the presence and dominance of onlookers, and by unsuccessful recovery attempts.[35]

In dogs[edit]

Dogs can use the pointing behaviour of humans to determine the location of food.

Domestic dogs (Canis familiaris) show an impressive ability to use the behaviour of humans to find food and toys using behaviours such as pointing and gazing. The performance of dogs in these studies is superior to that of NHPs,[36] however, some have stated categorically that dogs do not possess a human-like ToM.[12]

The Guesser-Knower approach has been used with ToM studies in dogs. In one study, each of two toys was placed on the dog’s side of two barriers, one opaque and one transparent. In experimental conditions, a human sat on the opposite side of the barriers, such that they could see only the toy behind the transparent barrier. The human then told the dog to ‘Fetch’ without indicating either toy in any way. In a control, the human sat on the opposite side but with their back turned so that they could see neither toy. In a second control, the human sat on the same side as the dog such that they could see both toys. When the toys were differentiable, dogs approached the toy behind the transparent barrier in experimental as compared to "back-turned" and "same-side" condition. Dogs did not differentiate between the two control conditions. The authors suggested that, even in the absence of overt behavioural cues, dogs are sensitive to others' visual access, even if that differs from their own.[37] Similarly, dogs preferentially use the behaviour of the human Knower to indicate the location of food. This is unrelated to the sex or age of the dog. In another study, 14 of 15 dogs preferred the location indicated by the Knower on the first trial, whereas chimpanzees require approximately 100 trials to reliably exhibit the preference.[36]

Human infants (10 months old) continue to search for hidden objects at their initial hiding place, even after observing them being hidden at another location; evidence indicates that communicative cues from the experimenter contribute to the perseverance of this searching error. Domestic dogs also commit more search errors in communicative trials than in non-communicative or non-social hiding trials. However, human-encultured wolves (Canis lupus) do not show these context-dependent differences of search errors. Shared sensitivity to human communication signals may arise from convergent evolution of the Homo and the Canis genera.[27]

Dogs which have been forbidden to take food are more likely to steal the food if a human observer has their back turned or eyes closed than when the human is looking at them. Dogs are also more likely to beg for food from an observer whose eyes are visible compared to an observer whose eyes are covered by a blindfold.[36]

In a study of the way that dogs interact, play signals were sent almost exclusively to forward-facing partners. In contrast, attention-getting behaviors were used most often when the other dog was facing away, and before signaling an interest to play. Furthermore, the type of attention-getting behaviour matched the inattentiveness of the playmate. Stronger attention-getting behaviours were used when a playmate was looking away or distracted, less forceful ones when the partner was facing forward or laterally,[38]

In pigs[edit]

In a tightly-controlled study, one out of 10 pigs behaved in a manner consistent with understanding that another pig had observed the location of a food-baiting event and therefore knew where food was, while another pig who, like itself, was occluded from the food-baiting event by a visual barrier, had no such knowledge. Most of the other pigs did not follow either potential informant. The researchers subsequently commented that although there are alternative (somewhat tortuous) explanations, it remains possible that the single pig genuinely demonstrated visual perspective taking,[39][40] i.e. ToM.

In goats[edit]

Like chimpanzees and some other NHPs, goats live in fission-fusion societies, form coalitions and alliances, and are known to reconcile after fights. Using the competitive feeding approach, a dominant and a subordinate goat compete for food, but in some cases the subordinate can see things that the dominant can not. In circumstances where dominants can only see one piece of food but subordinates can see both, subordinates’ preferences depend on whether they received aggression from the dominant animal during the study. Goats who received aggression prefer the hidden over the visible piece of food, whereas goats who never receive aggression prefer the visible piece. By using this strategy, goats who have not received aggression get significantly more food than the other goats.[41]

Further reading[edit]

  • Udell, M.A. and Wynne, C.D. (2011). Reevaluating canine perspective-taking behavior. Learning & Behavior, 39(4), 318-323.
  • Lurz, R.W. (2011). Mindreading Animals: The Debate Over What Animals Know About Other Minds. MIT Press
  • Whiten A. (1996) When does behaviour-reading become mind-reading. In, Theories of Theory of Mind (eds Caruthers P., Smith P. K.), pp. 277–292. New York, NY: Cambridge University Press


  1. ^ a b c Heyes, C. (2015). "Animal mindreading: what's the problem?". Psychonomic Bulletin & Review. 22 (2): 313–327.
  2. ^ a b Premack, D.G. and Woodruff, G. (1978). "Does the chimpanzee have a theory of mind?". Behavioral and Brain Sciences. 1 (4): 515–526. doi:10.1017/S0140525X00076512.
  3. ^ Elgier, A.M., Jakovcevic, A., Mustaca, A.E. and Bentosela, M. (2012). "Pointing following in dogs: are simple or complex cognitive mechanisms involved?". Animal Cognition. 15 (6): 1111–1119.
  4. ^ a b c Towner, S. (2010). "Concept of mind in non-human primates". Bioscience Horizons. 3 (1): 96–104. doi:10.1093/biohorizons/hzq011.
  5. ^ a b c Heyes, C.M. (1998). "Theory of mind in nonhuman primates". Behavioral and Brain Sciences. 21 (1): 101–114.
  6. ^ a b Hare, B., Call, J., Agnetta, B. and Tomasello, M. (2000). "Chimpanzees know what conspecifics do and do not see". Animal Behaviour. 59: 771–785.
  7. ^ a b c d Whiten, A. (2013). "Humans are not alone in computing how others see the world". Animal Behaviour. 86 (2): 213–221.
  8. ^ Calarge, C., Andreasen, N.C. and O’Leary, D.S. (2003). "Visualizing how one brain understands another: a PET study of theory of mind". American Journal of Psychiatry. 160: 1954–1964.
  9. ^ a b Penn, D.C. and Povinelli, D.J. (2007). "On the lack of evidence that non-human animals possess anything remotely resembling a 'theory of mind'". Philosophical Transactions of the Royal Society. 362: 731–744.
  10. ^ Jabr, F. (June 8, 2010). "Clever critters: Bonobos that share, brainy bugs and social dogs". Scientific American. Retrieved April 18, 2016.
  11. ^ Horowitz, A. (2011). "Theory of mind in dogs? Examining method and concept". Learning & Behavior. 39 (4): 314–317.
  12. ^ a b Bräuer, J. (2014). "Chapter 10 - What dogs understand about humans". In Kaminski, J. and Marshall-Pescini, S. The Social Dog: Behaviour and Cognition. Academic Press. pp. 295–317.
  13. ^ a b Butterfill, S.A. and Apperly, I.A. (2013). "How to construct a minimal theory of mind". Mind & Language. 28 (5): 606–637.
  14. ^ Call, J. and Tomasello, M. (1998). "Distinguishing intentional from accidental actions in orangutans (Pongo pygmaeus), chimpanzees (Pan troglodytes), and human children (Homo sapiens)". Journal of Comparative Psychology. 112 (2): 192–206. doi:10.1037/0735-7036.112.2.192. PMID 9642787.
  15. ^ Povinelli, D.J. and Vonk, J. (2003). "Chimpanzee minds: Suspiciously human?". Trends in Cognitive Sciences. 7 (4): 157–160. doi:10.1016/S1364-6613(03)00053-6. PMID 12691763.
  16. ^ Hamilton, J. (July 8, 2006). "A voluble visit with two talking apes". NPR. Retrieved March 21, 2012.
  17. ^ Call, J., Hare, B. and Tomasello, M. (1998). "Chimpanzee gaze following in an object choice task". Animal Cognition. 1: 89–99.
  18. ^ Povinelli, D. and Eddy, T. (1996). "What young chimpanzees know about seeing". Monographs of the Society for Research in Child Development. 61: 247.
  19. ^ Povinelli, D.J., Nelson, K.E. and Boysen, S.T. (1990). "Inferences about guessing and knowing by chimpanzees (Pan troglodytes)". Journal of Comparative Psychology. 104 (3): 203–210. doi:10.1037/0735-7036.104.3.203. PMID 2225758.
  20. ^ Hare, B., Call, J. and Tomasello, M. (2001). "Do chimpanzees know what conspecifics know and do not know?". Animal Behaviour. 61 (1): 139–151. doi:10.1006/anbe.2000.1518. PMID 11170704.
  21. ^ Schmelz, M., Call, J. and Tomasello, M. (2011). "Chimpanzees know that others make inferences". Proceedings of the National Academy of Sciences, USA. 108: 3077–3079.
  22. ^ Schmelz, M., Call, J. and Tomasello, M. (2013). "Chimpanzees predict that a competitor's preference will match their own". Biology Letters. 9: 20120829.
  23. ^ Melis, A.P., Call, J. and Tomasello, M. (2006). "Chimpanzees (Pan troglodytes) conceal visual and auditory information from others". Journal of Comparative Psychology. 120 (2): 154.
  24. ^ Flombaum, J.I. and Santos, L.R. (2005). "Rhesus monkeys attribute perceptions to others". Current Biology. 15: 447–452. doi:10.1016/j.cub.2004.12.076.
  25. ^ San‑Galli, A., Devaine, M., Trapanese, C., Masi, S., Bouret, S. and Daunizeau, J. (2015). "Playing hide and seek with primates: A comparative study of Theory of Mind". Revue de Primatologie. 6: 4–7.
  26. ^ Herrmann, E., Call, J., Hernández-Lloreda, M.V., Hare,B. and Tomasello, M. (2007). "Humans have evolved specialized skills of social cognition: The cultural intelligence hypothesis". Science. 317 (5843): 1360–1366.
  27. ^ a b Topál, J., Gergely, G., Erdőhegyi, A., Csibra, G. and Miklósi, A. (2009). "Differential sensitivity to human communication in dogs, wolves, and human infants". Science. 325 (5945): 1269–1272.
  28. ^ a b Emery, N.J. and Clayton, N.S. (2004). "The mentality of crows: convergent evolution of intelligence in corvids and apes". Science. 306 (5703): 1903–1907. Cite error: Invalid <ref> tag; name "Emery" defined multiple times with different content (see the help page).
  29. ^ Bugnyar, T. and Heinrich, B. (2006). "Pilfering ravens, Corvus corax, adjust their behaviour to social context and identity of competitors". Animal Cognition. 9 (4): 369–376.
  30. ^ Bugnyar, T. and Heinrich, B. (2005). "Ravens, Corvus corax, differentiate between knowledgeable and ignorant competitors". Proceedings of the Royal Society of London B: Biological Sciences. 272 (1573): 1641–1646.
  31. ^ MacDonald, T. (February 3, 2016). "Theory of mind: Ravens understand that others have minds, study says". Retrieved April 18, 2016.
  32. ^ Bugnyar, T., Reber, S.A. and Buckner, C. (2016). "Ravens attribute visual access to unseen competitors". Nature Communications. 7. doi:10.1038/ncomms10506.
  33. ^ Bugnyar, T. (2010). "Knower–guesser differentiation in ravens: others' viewpoints matter". Proceedings of the Royal Society of London B: Biological Sciences: rspb20101514. doi:10.1098/rspb.2010.1514.
  34. ^ Dally, J.M., Emery, N.J. and Clayton, N.S. (2006). "Food-caching western scrub-jays keep track of who was watching when". Science. 312 (5780): 1662–1665.
  35. ^ van der Vaart E., Verbrugge R. and Hemelrijk, C.K. (2012). "Corvid re-caching without 'Theory of Mind': A model". PLoS One. 7 (3): e32904. doi:10.1371/journal.pone.0032904.
  36. ^ a b c Maginnity, M.E. and Grace, R.C. (2014). "Visual perspective taking by dogs (Canis familiaris) in a Guesser–Knower task: evidence for a canine theory of mind?". Animal Cognition. 17 (6): 1375–1392.
  37. ^ Kaminski, J., Bräuer, J., Call, J. and Tomasello, M. (2009). "Domestic dogs are sensitive to a human's perspective". Behaviour. 146 (7): 979–998.
  38. ^ Horowitz, A. (2008). "Attention to attention in domestic dog (Canis familiaris) dyadic play". Animal Cognition. 12 (1): 107–18. doi:10.1007/s10071-008-0175-y. PMID 18679727.
  39. ^ Aldhous, P. (February 10, 2015). "The smartest animal you've never heard of". Wellcome Trust. Retrieved April 18, 2016.
  40. ^ Held, S., Mendl, M., Devereux, C. and Byrne, R.W. (2001). "Behaviour of domestic pigs in a visual perspective taking task". Behaviour. 138 (11): 1337–1354.
  41. ^ Kaminski, J., Call, J. and Tomasello, M. (2006). "Goats' behaviour in a competitive food paradigm: Evidence for perspective taking?". Behaviour. 143 (11): 1341–1356.

External links[edit]

Main PageJimbo Peeking.gif

Soring has been described as "cruel" by the USDA,[1] and "inhumane"[2] and "unethical".[3]

by the American Veterinary Medical Association (AVMA)[4]

Feather duster budgerigars (Melopsittacus undulatus) have a condition characterised by overly long feathers that do not 'sit down' in the usual way, giving the bird the appearance of a feather duster. This is sometimes known as chrysanthemum feathering. The contour, tail and flight feathers do not stop growing, and they do not have the necessary barbs and barbules for the feather's structure to interlock. The shaft (calumus) is also curved, and so the feathers appear deformed and fluffed out. Individuals with this condition often appear less alert than nest mates. In addition, they are small and some have other defects such as microphthalmia. They lack vigour, often cannot fly and die within a year of hatching. There is no treatment for the condition; birds are often euthanized in the nest.

The condition may be a genetic disorder,[5][6] but others have suggested it is cause by a herpesvirus.[7][8] It has also been indicated the condition can be caused by both.[9]

External links[edit]

Video of feather duster budgerigar [14]


  1. ^ Cite error: The named reference HPA2016 was invoked but never defined (see the help page).
  2. ^ "AVMA CEO testimony on the Prevent All Soring Tactics Act: 2013". American Veterinary Medical Association. Retrieved April 4, 2016.
  3. ^ "Soring horses: Unethical practice making horses suffer". American Veterinary Medical Association. Retrieved April 4, 2016.
  4. ^ Cite error: The named reference USDA was invoked but never defined (see the help page).
  5. ^ Pass, D.A. (1989). "The pathology of the avian integument:A review". Avian Pathology. 18 (1): 1–72.
  6. ^ van Zeeland, Y.R. and Schoemaker, N.J. (2014). "Plumage disorders in psittacine birds-part 1: Feather abnormalities". European Journal of Companion Animal Practice. 24 (1): 34–47.
  7. ^ Shivaprasad, H.L. (2002). "Pathology of birds–an overview". Proceedings of C.L. Davis Foundation Conference on Gross Morbid Anatomy of Animals. AFIP, Washington DC.
  8. ^ Lazic, T., Ackermann, M.R., Drahos, J.M., Stasko, J. and Haynes, J.S. (2008). "Respiratory herpesvirus infection in two Indian Ringneck parakeets". Journal of Veterinary Diagnostic Investigation. 20: 235–238.
  9. ^ Girling, S.J. (2010). "The welfare of captive birds in the future". The Welfare of Domestic Fowl and Other Captive Birds. Springer Netherlands. pp. 115–133.

Timeline of block Much of the problem here seems to focus on JzG's block of Claudioalv. I have prepared below a timeline of the relevant edits.

  • (22:48, 9 February) Claudioalv's second contribution ever is again to the Talk:European Graduate School page here.[16]
  • (00:20, 10 February) JzG reverts Claudioalv here[17]. Reverting another user's posting on a talk page is in itself actionable.
  • (00:20, 10 February) Jzg indefinitely blocks Claudioalv, leaving edit summary "(Abusing multiple accounts)" according to Claudioalv's block log.
  • (16:16, 10 February) Claudioalv's first contribution to their own talk page was here[18] asking to have their block lifted.
  • (23:48, 16 February) Jzg's first ever contribution to Claudioalv's Talk page is here[19].
In other words, I am unable to find any evidence of a discussion about any problem that JzG had with Claudioalv before blocking them. Claudioalv does not have appear to have been warned about the possibility of a block, nor indeed even notified about their block. Is this really the way to WP:AGF and treat a new editor?

Information relating to whether boiling a partially-developed embryo is ethically acceptable or not can be found in the legislation relating to the euthanasia of laboratory animals. In the UK, embryonic and fetal forms of mammals, birds and reptiles are "protected animals" once they have reached the last third of their gestation or incubation period.[1] There are specified methods of humanely killing protected animals used in research, but boiling is not one of these. Depending on the species of duck, some of these eggs would be boiled within this last third of embryo development.

@jps I think you have misunderstood me. The examples I gave above were to indicate that when I am editing those or similar articles, I know that I could further contribute positively to them, but I am prevented by my TB. Effectively, I am leaving articles "unfinished" which can not be benefiting the project. I am totally disbelieving of almost all forms of I am not sure quite how to state this more clearly but in, for example, the Bile bear article, I would like to write (perhaps in a slightly more encyclopaedic tone),

"The cruel bastards who keep these wonderful, sentient mammals in such horrendous conditions, do so because some poor, deluded idiot believes that drinking bear bile will make his erection last longer. This belief is complete bullshit, as shown by (insert multiple WP:MEDRS sources here)".
I believe in producing balanced articles. Unfortunately, many animals are used in and I feel that a balanced article would provide information about this, countered by mainstream science to indicate the nonsense and quackery that is associated with the purported benefits. I do not see what is wrong with this approach.

Editing articles which have sections was, and will remain, a tiny part of my editing habits. Even a cursory glance at my User contributions page here[20] will convince you that I edit many, many articles which have absolutely nothing to do with The project has nothing to fear from me.DrChrissy (talk) 18:14, 11 March 2016 (UTC)

I have no specific plan or agenda of articles to edit if this ban is lifted. The reasons I want this TB lifted are so that I can further improve the encyclopaedia and simultaneously lift the frustration that I have been editing with for over 9 months. Please bear in mind that I have been warned I am to make no comment whatsoever on these topics - not even to mention them on my Talk page or Sandbox. So, I have had to avoid deleting, adding or commenting on these areas, or sections of any pages discussing these, whilst editing productively in widespread topics. Many articles I edit in animal behaviour and welfare science have an underlying overlap with aspects of my TB that may not be immediately apparent, but I have had to be careful to avoid even mentioning them. I offer examples in each of the substantive areas of the TB.

  • I have recently been editing the Bile bear article. Bile bears are kept under horrendous conditions for the purpose of collecting bile and their gall bladders, which are used in Despite User:Guy's repeated assertions that I am pro-quackery, I am not. Far from it. I am very much against quackery and pseudoscience, but especially where it negatively impinges on animal welfare. In researching material for the article, I have found many sources where the quackery around bile products is robustly debunked. However, inserting this would be a breach of my TB. I believe this is a net loss to the project. To add to the complications, an editor (User:Guy) has been adding content to the article. So, this initially felt like I was a submarine trying to navigate an underwater minefield, but then, along comes a destroyer and starts dropping depth charges on me! The article Dog meat (humans eating dogs) is similar to Bile bear in that there are absolutely ridiculous claims about "magical" benefits to humans who eat dog flesh. It would benefit the article and project if my TB was lifted and I am able to make the edits indicating how ridiculous these are.
  • Medicine and health: Recently, the article Equine-assisted therapy and associated articles underwent major editing or re-writes. I am aware of much of the literature on anthrozoology (scientific study of interaction between humans and other animals) and I felt I could have benefited the articles with this knowledge. However, given the overall intent behind the articles (human health), I felt this was within the scope of my TB so I did not make any edits. Again, I feel this is a net loss to the project. A similar article is Assistance dog. I also edit heavily in articles on Pain in animals, Pain in fish, Pain in crustaceans and Pain in amphibians - again these articles would be improved if I were able to make edits relating to the science of human pain, but the TB prevents me from doing so.
  • Wp:MEDRS I have no desire whatsoever to edit this page. I often engage in discussions elsewhere about the suitability of scientific sources. The subject of MEDRS frequently arises in these discussions and again I must adopt a "submarine in a minefield with a destroyer overhead" approach. I have over 20 years experience of publishing scientific articles in mainstream science journals (including Nature) and I work on several scientific journal editorial boards. I feel this experience is invaluable in these discussions of sources, but I frequently remain silent because I am aware that some people are wanting to play "gotcha" if I mention MEDRS. Lifting my ban will allow me to improve the project in this area.

  • On May 20th 2015, I was topic banned here [[21]] by @Awilley: for 6 months. The locus relates to three broad subjects (1) alternative medicine, (2) WP:MEDRS and (3) Human medicine articles.
  • I applied to have my TB lifted here [[22]]. @Dennis Brown: carefully considered the discussion and decided that my ban should be re-visited in 3 months. This was primarily, I believe, because at the time I was involved in an Arbcom case, rather than non-adherance of the TB (Dennis, I hope I am not misrepresenting you here). I am now (re-)seeking to have the TB lifted.
  • During the last 3 months, I have not edited any pages in the area of my TB or entered into discussions about them. I cannot recollect any comments from other editors that I have come close to violating the TB or attempted to skirt the TB. I also cannot recollect asking either of the closing admins, or others, for advice regarding the extent of my TB during the last 3 months – indicating I have consciously stayed unambiguously away from the topic areas.
  • I believe that when admins are looking for evidence of why a TB should be lifted, they are wanting to see constructive editing in areas away from the TB. I will not repeat the evidence I presented at my last request, rather, I offer the following as evidence of my editing behaviour during the last 3 months.
Created: Grimace scale (animals)
Major re-writes: Pain in crustaceans, Bile bear, Hair whorl (horse)
Others (examples): Killing of Cecil the lion, Emotion in animals, Personality in animals
Community discussion or edits: Wikipedia:Reliable sources/Noticeboard, Wikipedia:Reference desk/Science, Wikipedia:Village pump (policy)
  • My TB has successfully prevented the topic areas from being disrupted by myself for the last 9 months. During this time, I have reflected upon how I caused disruption in the topic areas and I have adjusted my thinking and editing to ensure that going forward, I will not cause further disruption. The topic ban has achieved its objective and I request it now be lifted.

DrChrissy (talk) 21:12, 6 March 2016 (UTC)

Wikipedia:Administrators' noticeboard#Request to lift the topic ban of DrChrissy Opening comments [[23]]

Criteria for pain perception[edit]

Scientists have also proposed that in conjunction with argument-by-analogy, criteria of physiology or behavioural responses can be used to assess the possibility of non-human animals perceiving pain. The following is a table of criteria suggested by Sneddon et al.[2]

Criteria for pain reception in crustaceans

Eudontomyzon danfordi Tiszai ingola.jpg


Shark fish chondrichthyes.jpg


Carassius wild golden fish 2013 G1.jpg

Prawns (shrimps)


Has nociceptors ? ? Green tickY ?
Pathways to central nervous system ? ? Green tickY ?
Central processing in brain ? ? Green tickY ?
Receptors for analgesic drugs ? ? Green tickY ?
Physiological responses ? ? Green tickY ?
Movement away from noxious stimuli ? ? Green tickY ?
Behavioural changes from norm ? ? Green tickY ?
Protective behaviour ? ? Green tickY ?
Responses reduced by analgesic drugs ? ? Green tickY ?
Self-administration of analgesia ? ? Green tickY ?
Responses with high priority over other stimuli ? ? Green tickY ?
Pay cost to access analgesia ? ? Green tickY ?
Altered behavioural choices/preferences ? ? Green tickY ?
Relief learning ? ? Green tickY ?
Rubbing, limping or guarding ? ? Green tickY ?
Paying a cost to avoid stimulus ? ? Green tickY ?
Tradeoffs with other requirements ? ? Green tickY ?

In the table, Green tickY indicates positive evidence and ? denotes it has not been tested or there is insufficient evidence.


This is a request to review the non-admin close here[25] at WP:ANI#Admin edits my post to deliberately change the meaning to determine whether the closer interpreted the consensus incorrectly. I discussed this with the non-admin closer here[26] to which s/he replied here [27] and stated "Now don't bother me about this again".

I believe the close by User:Tarage was an inappropriate and inaccurate distillation of the discussion. The closer indicated the reason for closure was that the Discussion should not have been re-opened. The discussion had previously been closed by an admin here[28], however, they disclosed they were involved and invited reopening if this was objected to. I requested it be reopened which it subsequently was by an admin here.[29]. This effectively means the non-admin user:Tarage closed down a Discussion re-opened by an admin only hours previously. Please note, the only comment regarding closure throughout the entire Discussion was one comment made before the non-admin's closure - one comment does not make consensus. Furthermore, the non-admin made no comment whatsoever about the subject of the thread - a serious complaint that one editor/admin had altered another's edit to change the meaning.

I am requesting that a warning is given to User:JzG for his editing of my post here.[30] Jpz has clearly edited to deliberately misrepresent my meaning to other readers. I politely asked JzG to revert his edit, but he has since replied[31] refusing to do this.

JzG's edit clearly deliberately changes the entire meaning of my post. This is in violation of the Behavioural Guidelines WP:TPG which state The basic rule—with some specific exceptions outlined below—is that you should not edit or delete the comments of other editors without their permission.

I also point out that my edit was intended to show the table was submitted in an ArbCom case and so it is possible that JzG has violated DS issued by ArbCom regarding this case - I would welcome advice from admins on whether this disruptive edit should be raised at AE rather than here (or perhaps simultaneously).

It is perhaps easiest to show the deliberately intended change of the meaning of my post by showing "before and after" of the table I introduced into the talk page.

BEFORE i.e. my edit

Potentially Actionable Behaviour Proposed Remedy
Incivility Edit warring Tag team editing Misuse of DR Forum shopping Battleground behaviour
DrChrissy (me) - Green tickY - - - - Topic ban
Kingofaces43 - Green tickY Green tickY - - Green tickY None proposed
Alexbrn - Green tickY Green tickY - - - None proposed
Yobol - Green tickY Green tickY - - Green tickY None proposed

After i.e. my edit after Jzg's edit

Potentially Actionable Behaviour Proposed Remedy
Incivility Edit warring Tag team editing Misuse of DR Forum shopping Battleground behaviour
DrChrissy (me) Green tickY Green tickY Green tickY Green tickY Green tickY Green tickY Topic bans (2)
Kingofaces43 - Green tickY Green tickY - - Green tickY None proposed
Alexbrn - Green tickY Green tickY - - - None proposed
Yobol - Green tickY Green tickY - - Green tickY None proposed

OK, let's put this to bed once and for all. This diff shows where I originally inserted the disputed material.[32] (Please note the material is a quote by Mercola, not Mercola's own words.) You then deleted the content here[33] with the Edit Summary "Mercola is a completely unreliable source" - you gave no further information. No discussion was opened on the Article Talk page regarding the the reliability of the source. I re-inserted the disputed content here[34] leaving the ES "Is a quote and therefore reference is RS..." Kingofaces43 then removed the content here[35] leaving "Remove WP:FRINGE source and undue weight for a non-expert..." I did not attempt to re-insert the material. Those are the facts. I reverted material which had been disputed with minimal justification just the once - yes, once. I refute your accusation that I am a promoter of fringe or a POV-pusher. You have also accused me of being a Civil POV-pusher. Perhaps if I told you to "F*CK OFF and leave me alone", I could also refute the civility aspect of that particular accusation, but I will not do that.

Grimace scale (animals)[edit]

A drawing by Konrad Lorenz showing facial expressions of a dog

The grimace scale (GS), sometimes called the grimace score, is a method of assessing the occurrence or severity of pain experienced by non-human animals according to objective and blinded scoring of facial expressions, as is done routinely for the measurement of pain in non-verbal humans. Observers score the presence or prominence of “facial action units" (FAU), e.g. Orbital Tightening, Nose Bulge, Ear Position and Whisker Change. These are scored by observing the animal directly in real-time, or post hoc from photographs or screen-grabs from videos. The facial expression of the animals is sometimes referred to as the pain face.

The GS method of pain assessment is highly applicable to laboratory rodents as these are usually prey species which tend to inhibit the expression of pain to prevent appearing vulnerable to predators. For this reason, behavioural changes in these species are mainly observed with acute pain (hours) but are less pronounced in longer-lasting pain (days).[3]

For mice at least, the GS has been shown to be a highly accurate, repeatable and reliable means of assessing pain requiring only a short period of training for the observer. [4][5] Across species, GS are proven to have high accuracy and reliability, and are considered useful for indicating both procedural and postoperative pain, and for assessing the efficacy of analgesics.[6][7]

The overall accuracy of GS is reported as 97% for mice, 84% for rabbits, 82% for rats and 73.3% for horses.[citation needed]


Facial expressions have long been considered as indicators of emotion in both human and non-human animals. The biologist, Charles Darwin, considered that non-human animals exhibit similar facial expressions to emotional states as do humans. The assessment of changes in human anatomy during facial expressions were successfully translated from humans to non-human primates, such as the chimpanzee (ChimpFACS[36])[8] and rhesus macaque (MaqFACS[37])[9], but were not originally applied to assess pain in these species. In 2010, a team of researchers successfully developed[10] the first method to assess pain using changes in facial expression in any non-human animal species. Broadly speaking, GS quantify spontaneous pain according to objective and blinded scoring of facial expressions, as is done routinely for the measurement of pain in non-verbal humans. Observers score the presence and extent of "facial action units" (FAU), e.g. Orbital Tightening, Nose Bulge, Ear Position and Whisker Change. These are scored in real-time by observing the animal directly, or, post hoc from photographs or screen-grabs from videos.

This method of pain assessment highly applicable to prey animals which tend to inhibit the overt expression of pain to prevent appearing vulnerable to predators. For this reason, behavioural changes in these species are mainly observed with acute pain (hours) but are less pronounced in longer-lasting pain (days).[3]

GS offer advantages over other methods of pain assessment. For example, the analgesic morphine reduces pain but can affect other aspects of behaviour in pain-free animals, for example, excitement, increased activity or sedation, which can hamper traditional behavioural assessment of its action on pain. Morphine not only reduces the frequency of “pain faces” but has no effect on GS in baseline, pain-free mice.[11]

In mice[edit]

The GS for mice usually consists of five FAU, i.e. Orbital Tightening, Nose Bulge, Cheek Bulge, Ear position and Whisker Change. These are scored on a 0-2 scale where 0=the criterion is absent, 1=moderately present and 2=obviously present (for exemplar images, see here [38]). In mice, the GS offers a means of assessing post-operative pain that is as effective as manual behavioural-based scoring, without the limitations of such approaches.

Facial grimacing by mice after undergoing laparotomy surgery indicates postoperative pain lasts for 36 to 48 h (and at relatively high levels for 8 to 12 h) with relative exacerbation during the early dark (active) photo-phase. Furthermore, the grimacing indicates that buprenorphine is fully efficacious at recommended doses against early postoperative pain, but carprofen and ketoprofen are efficacious only at doses much higher than currently recommended: acetaminophen is not efficacious.[12]

A study in 2014 examined postoperative pain in mice following surgical induction of myocardial infarction. The effectiveness of the GS at identifying pain was compared with a traditional welfare scoring system based on behavioural, clinical and procedure-specific criteria. It was reported that post hoc GS (but not real-time GS) indicated a significant proportion of the mice were in low-level pain at 24 h which were not identified as such by traditional assessment methods. Importantly, those mice identified as experiencing low-level pain responded to analgesic treatment, indicating the traditional methods of welfare assessment were insensitive in this aspect of pain recognition.[3]

Mice with induced sickle cell disease and their controls exhibited a "pain face" when tested on a cold plate, but sickle mice showed increased intensity compared to controls; this was confirmed using Von Frey filaments a traditional method of pain assessment.[13] GS have also been used to assess pain and methods of its alleviation in pancreatitis.[14] GS have also been used to test the degree of pain caused as a side-effect of therapeutic drugs and methods of mitigating the pain.[15]

The mouse GS has been shown to be a highly accurate, repeatable and reliable means of assessing pain, requiring only a short period of training for the observer.[4]

Sex and strain effects[edit]

It has been noted that DBA/2 strain mice, but not CBA strain mice, show an increase in GS score following only isoflurane anaesthesia, which should be taken into account when using the GS to assess pain. Administration of a common analgesic, buprenorphine, had no effect on the GS of either strain.[16]

There are interactions between the sex and strain of mice in their GS and also the method that is used to collect the data (i.e. real-time or post hoc), which indicates scorers need to consider these factors.Cite error: A <ref> tag is missing the closing </ref> (see the help page). A similar study reported there was no difference between GS scores at baseline and immediately post-ear notching (a method frequently used to identify laboratory mice), potentially indicating that the pain associated with ear notching is either too acute to assess using GS, or the practice is not painful.[17]

Effects of non-painful procedures[edit]

It is important to establish whether methods of pain assessment in laboratory animals are influenced by other factors, especially those which are a normal part of routine procedures or husbandry. There is no difference in GS scores between mice handled using a tube compared with mice picked up by the tail, indicating these handling techniques are not confounding factors in GS assessment.[18] A similar study reported there was no difference between GS scores at baseline and immediately post ear notching (a method frequently used to identify laboratory mice), potentially indicating that the pain associated with ear notching is either too acute to assess using the GS tool or the practice is not painful.[17]

In rats[edit]

There are differences between the "pain face" of mice and rats. In mice, the nose and cheek at baseline have a smooth appearance, but in the presence of pain, change to distinct bulges in both the nose and cheek regions. By contrast, in rats at baseline, the nose and cheek regions show distinct bulging, and with pain, the bridge of the nose flattens and elongates causing the whisker pads to flatten. As a consequence of these differences, the GS for rats sometimes use four FAU, i.e. Orbital Tightening, Nose/Cheek Flattening, Ear Changes and Whisker Changes. Nose/Cheek Flattening, appears to show the highest correlation with the presence of pain in the rat.[19][5]

GS for rats has been used to assess pain due to surgery, orthodontic tooth movement, and the efficacy of analgesics for these procedures and other painful conditions.[20][21][22][23][19] Furthermore, GS have been used to examine the effects of postoperative analgesia on the reduction of post-operative cognitive dysfunction in aged rats.[24]

As with mice, studies have examined the extent of agreement in assessing pain between rat GS and the use of von Frey filaments. Good agreement has been found between these[25] in relation to three models of pain (intraplantar carrageenan, intraplantar complete Freund's adjuvant and plantar incision). The GS score significantly increased in all pain models and the peak GS score also coincided with the development of paw hypersensitivity, although hypersensitivity persisted after GS scores returned to baseline.[26]

For rats, software (Rodent Face Finder®) has been developed which successfully automates the most labour-intensive step in the process of quantifying the GS, i.e. frame-grabbing individual face-containing frames from digital video, which is hindered by animals not looking directly at the camera or poor images due to motion blurring.[27]

In rabbits[edit]

A GS for rabbits using four FAU, i.e. Orbital Tightening, Cheek Flattening, Nose Shape, Whisker Position (Ear Position is excluded from the analysis) has been developed (for exemplar images, see here[39]) and used to assess the effectiveness of an analgesic cream for rabbits having undergone ear-tattooing.[28] Similarly, a GS has been used to evaluate wellness in the post-procedural monitoring of rabbits.[29]

In horses[edit]

A GS for horses has been developed from post-operative (castration) individuals. This is based on six FAU, i.e. Stiffly Backwards Ears, Orbital Tightening, Tension Above the Eye Area, Prominent Strained Chewing Muscles, Mouth Strained and Pronounced Chin, Strained Nostrils and Flattening of the Profile (for exemplar images, see here.[40])[30]

A related study[31] stated that the equine “pain face” involves low and/or asymmetrical ears, an angled appearance of the eyes, a withdrawn and/or tense stare, medio-laterally dilated nostrils and tension of the lips, chin and certain mimetic muscles and can potentially be incorporated to improve existing pain evaluation tools.

In cats[edit]

Observers shown facial images from painful and pain-free cats had difficulty in identifying pain-free from painful cats, with only 13% of observers being able to discriminate more than 80% of painful cats.[32]

In sheep (lambs)[edit]

A GS has been used to assess pain due to the routine husbandry procedure of tail-docking in lambs. There was high reliability between and within the observers, and high accuracy. Restraint of the lambs during the tail-docking caused changes in facial expression, which needs to be taken into account in use of the GS.[33]

See also[edit]

The Three Rs (animals)


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