Dog behavior

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Dogs roughhousing.

Dog behavior is the range of actions and mannerisms made by the domestic dog, Canis lupus familiaris, in conjunction with themselves or their environment, which includes other organisms as well as the inanimate physical environment. It is the response of dogs to various stimuli or inputs, whether internal or external, conscious or subconscious, overt or covert, and voluntary or involuntary.

Evolution/Domestication/Co-evolution with humans[edit]

The origin of the domestic dog (Canis lupus familiaris or Canis familiaris) is not clear. Nuclear DNA evidence points to a single domestication 11,000-16,000 years ago that predates the rise of agriculture and implies that the earliest dogs arose along with hunter-gatherers and not agriculturists.[1] Mitochondrial DNA evidence points to a domestication 18,800-32,100 years ago and that all modern dogs are most closely related to ancient wolf fossils that have been found in Europe,[2][3] compared to earlier hypotheses which proposed origins in Eurasia as well as Eastern Asia.[4][5][6] The 2 recent genetic analyses indicate that the dog is not a descendant of the extant (i.e. living) gray wolf but forms a sister clade, that the ancestor is an extinct wolf-like canid and the dog's genetic closeness to modern wolves is due to admixture.[1][7]

How dogs became domesticated is not clear, however the two main hypothesis are self-domestication or human domestication.

There exists evidence of human-canine coevolution.

Cognition[edit]

Further information: Animal cognition

Cognition is the set of all mental abilities and processes related to knowledge: attention, memory and working memory, judgement and evaluation, reasoning and "computation", problem solving and decision making, comprehension and production of communication. Although dogs have been the subject of a great deal of behaviorist psychology (e.g. Pavlov's dog), they do not enter the world with a psychological "blank slate". Rather, dog behavior is affected by genetic as well as environmental factors.[8]

As the oldest domesticated species, with estimates ranging from 9,000–30,000 years BCE, the minds of dogs inevitably have been shaped by millennia of contact with humans.[9][10] As a result of this physical and social evolution, dogs, more than any other species, have acquired the ability to understand and communicate with humans. A resurgence of research in canine cognition has revealed the range (and variability) of skills such as following pointing and gaze cues[11][12][13] fast mapping of novel words[14] and the conjecture that dogs have emotions.[15]

In a problem solving experiment dominant dogs generally performed better than subordinate ones, but only when they observed a human demonstrator’s action. This suggests that social rank affects performance in social learning situations and that in social groups with clear hierarchy, dominant individuals will be the more influential demonstrators and the knowledge transfer will, therefore, be unidirectional. If dog-human groups are regarded as social units with some type of internal hierarchy, humans are usually considered as the leaders. In this scenario, the human will be the most influential demonstrator for the dominant dog. The subordinate dogs will learn better from the dominant dog that is next in the hierarchy.[16]

Senses[edit]

Further information: Dog § senses

Vision[edit]

Frequency sensitivity compared with humans.

Like most mammals, dogs have only two types of cone photoreceptor, making them dichromats.[17][18][19][20] These cone cells are maximally sensitive between 429 nm and 555 nm. Behavioural studies have shown that the dog's visual world consists of yellows, blues and grays,[20] but they have difficulty differentiating red and green making their color vision equivalent to red–green color blindness in humans (deuteranopia). When a human perceives an object as "red", this object appears as "yellow" to the dog and the human perception of "green" appears as "white", a shade of gray. This white region (the neutral point) occurs around 480 nm, the part of the spectrum which appears blue-green to humans. For dogs, wavelengths longer than the neutral point cannot be distinguished from each other and all appear as yellow.[20]

The dog's visual system has evolved to aid proficient hunting.[17] While a dog's visual acuity is poor (that of a poodle's has been estimated to translate to a Snellen rating of 20/75[17]), their visual discrimination for moving objects is very high; dogs have been shown to be able to discriminate between humans (e.g., identifying their human guardian) at a range of between 800 and 900 metres (2,600 and 3,000 ft), however this range decreases to 500–600 metres (1,600–2,000 ft) if the object is stationary.[17]

Olfaction[edit]

While the human brain is dominated by a large visual cortex, the dog brain is dominated by an olfactory cortex. The olfactory bulb in dogs is roughly forty times bigger than the olfactory bulb in humans, relative to total brain size, with 125 to 220 million smell-sensitive receptors. The bloodhound exceeds this standard with nearly 300 million receptors.[8]

Hearing[edit]

Anatomy of the ear.

The frequency range of dog hearing is approximately 40 Hz to 60,000 Hz,[21] which means that dogs can detect sounds far beyond the upper limit of the human auditory spectrum.[19][21][22] In addition, dogs have ear mobility, which allows them to rapidly pinpoint the exact location of a sound.[23] Eighteen or more muscles can tilt, rotate, raise, or lower a dog's ear. The ears are often used in communication of, for example, the dog's mood.[citation needed] A dog can identify a sound's location much faster than a human can, as well as hear sounds at four times the distance.[23]

Social behavior[edit]

Further information: Dog communication

Play[edit]

Dog-dog[edit]

Playtime

Play between dogs usually involves several behaviours that are often seen in aggressive encounters, for example, nipping, biting, growling and biting. It is therefore important for the dogs to place these behaviours in the context of play, rather than aggression. Dogs signal their intent to play with a range of behaviours including a "play-bow", "face-paw" "open-mouthed play face" and postures inviting the other dog to chase the initiator. Similar signals are given throughout the play bout to maintain the context of the potentially aggressive activities.[24]

From a young age, dogs engage in play with one another. Dog play is made up primarily of mock fights. It is believed that this behavior, which is most common in puppies, is training for important behaviors later in life. Play between puppies is not necessarily a 50:50 symmetry of dominant and submissive roles between the individuals; dogs who engage in greater rates of dominant behaviours (e.g. chasing, forcing partners down) at later ages also initiate play at higher rates. This could imply that winning during play becomes more important as puppies mature.[25]

Dog-human[edit]

The motivation for a dog to play with another dog is distinct from that of a dog playing with a human. Dogs walked together with opportunities to play with one another, play with their owners with the same frequency as dogs being walked alone. Dogs in households with two or more dogs play more often with their owners than dogs in households with a single dog, indicating the motivation to play with other dogs does not substitute for the motivation to play with humans.[26]

It is a common misconception that winning and losing games such as "tug-of-war" and "rough-and-tumble" can can influence a dog's dominance relationship with humans. Rather, the way in which dogs play indicates their temperament and relationship with their owner. Dogs that play rough-and-tumble are more amenable and show lower separation anxiety than dogs which play other types of games, and dogs playing tug-of-war and "fetch" are more confident. Dogs which start the majority of games are less amenable and more likely to be aggressive.[27]

Playing with humans can affect the cortisol levels of dogs. In one study, the cortisol responses of police dogs and border guard dogs was assessed after playing with their handlers. The cortisol concentrations of the police dogs increased, whereas the border guard dogs' hormone levels decreased. The researchers noted that during the play sessions, police officers were disciplining their dogs, whereas the border guards were truly playing with them, i.e this included bonding and affectionate behaviours. They commented that several studies have shown that behaviours associated with control, authority or aggression increase cortisol, whereas play and affiliative behaviour decrease cortisol levels.[28]

Empathy[edit]

In 2012, a study found that dogs oriented toward their owner or a stranger more often when the person was pretending to cry than when they were talking or humming. When the stranger pre-tended to cry, rather than approaching their usual source of comfort, their owner, dogs sniffed, nuzzled and licked the stranger instead. The dogs’ pattern of response was behaviorally consistent with an expression of empathic concern.[29]

Personalities[edit]

Several personality traits in dogs are recognised. These include "Playfulness", "Curiosity/Fearlessness, "Chase-proneness", "Sociability and Aggressiveness" and "Shyness–Boldness".[30][31]

Leadership, dominance and social groups[edit]

Follow the leader

Dominance is a descriptive term for the relationships between pairs of individuals. Among ethologists, dominance is normally defined as ‘‘an attribute of the pattern of repeated, agonistic interactions between two individuals, characterized by a consistent outcome in favor of the same dyad member and a default yielding response of its opponent rather than escalation. The status of the consistent winner is dominant and that of the loser subordinate.’’[32] There is no reason to assume that a high-ranking individual in one group would also become high ranking if moved to another. Nor is there any good evidence that ‘‘dominance’’ is a lifelong character trait. Competitive behavior was characterized by confident (e.g. growl, inhibited bite, stand over, mount, stare at, chase, bark at) and submissive (e.g. crouch, avoid, displacement lick/yawn, run away) patterns exchanged.[33]

One test to ascertain which in a group was the dominant dog used the following criteria: When a stranger comes to the house, which dog starts to bark first or if they start to bark together, which dog barks more or longer? Which dog licks more often the other dog’s mouth? If the dogs get food at the same time and at the same spot, which dog starts to eat first or eats the other dog’s food? If the dogs start to fight, which dog wins usually?[34]

Domestic dogs appear to pay little attention to relative size, despite the large weight differences between the largest and smallest individuals; for example, size was not a predictor of the outcome of encounters between dogs meeting while being exercised by their owners nor was size correlated with neutered male dogs.[35] Therefore, many dogs do not appear to pay much attention to the actual fighting ability of their opponent, presumably allowing differences in motivation (how much the dog values the resource) and perceived motivation (what the behavior of the other dog signifies about the likelihood that it will escalate) to play a much greater role.[33]

Two dogs that are contesting possession of a highly valued resource for the first time, if one is in a state of emotional arousal, or if one is in pain, or if reactivity is influenced by recent endocrine changes or motivational states such as hunger, then the outcome of the interaction may be different than if none of these factors were present. Equally, the threshold at which aggression is shown may be influenced by a range of medical factors, or, in some cases, precipitated entirely by pathological disorders. Hence, the contextual and physiological factors present when 2 dogs first encounter each other may profoundly influence the long-term nature of the relationship between those dogs. The complexity of the factors involved in this type of learning means that dogs may develop different ‘‘expectations’’ about the likely response of another individual for each resource in a range of different situations. Puppies learn early not to challenge an older dog and this respect stays with them into adulthood. When adult animals meet for the first time, they have no expectations of the behavior of the other: they will both, therefore, be initially anxious and vigilant in this encounter (characterized by the tense body posture and sudden movements typically seen when 2 dogs first meet), until they start to be able to predict the responses of the other individual. The outcome of these early adult–adult interactions will be influenced by the specific factors present at the time of the initial encounters. As well as contextual and physiological factors, the previous experiences of each member of the dyad of other dogs will also influence their behavior.[33]

Feral dogs[edit]

In 2004, a study reviewed 5 other studies of feral dogs published between 1975 and 1995 and concluded that their pack structure is very loose and rarely involves any cooperative behavior, either in raising young or in obtaining food.[36] Feral dogs are primarily scavengers, with studies showing that unlike their wild cousins, they are poor ungulate hunters, having little impact on wildlife populations where they are sympatric. However, feral dogs have been reported to be effective hunters of reptiles in the Galápagos Islands.[37]:267

Reproduction behavior[edit]

Behavior problems[edit]

A survey of 203 dog owners in Melboourne, Australia, found that the main behaviour problems reported by owners were overexcitement (63%) and jumping up on people (56%).[38]

Separation anxiety[edit]

When dogs are separated from humans, usually the owner, they often display behaviours such as destructiveness, faecal or urinary elimination, hypersalivation or vocalisation. Dogs from single-owner homes are approximately 2.5 times more likely to have separation anxiety compared to dogs from multiple-owner homes. Futhermore, sexually intact dogs are only one third as likely to have separation anxiety as neutered dogs. The sex of dogs and whether their is another pet in the home do not have an affect on separation anxiety.[39]

Tail chasing[edit]

Tail chasing can be classified as a stereotypy. In one clinical study on the behaval problem, 18 tail-chasing terriers were given clomipramine orally at a dosage of 1 to 2 mg/kg (0.5 to 0.9 mg/lb) of body weight, every 12 hours. Three of the dogs required treatment at a slightly higher dosage range to control tail chasing, however, after 1 to 12 weeks of treatment, 9 of 12 dogs were reported to have a 75% or greater reduction in tail chasing.[40]

Comparison of behavior with other canids[edit]

After undergoing training to solve a simple manipulation task, dogs that are faced with an insoluble version of the same problem look at the human, while socialized wolves do not.[41]

In 1982, a study to observe the differences between dogs and wolves raised in similar conditions took place. The dog puppies preferred larger amounts of sleep at the beginning of their lives, while the wolf puppies were much more active. The dog puppies also preferred the company of humans, rather than their canine foster mother, though the wolf puppies were the exact opposite, spending more time with their foster mother. The dogs also showed a greater interest in the food given to them and paid little attention to their surroundings, while the wolf puppies found their surroundings to be much more intriguing than their food or food bowl. The wolf puppies were observed taking part in agonistic play at a younger age, while the dog puppies did not display dominant/submissive roles until they were much older. The wolf puppies were rarely seen as being aggressive to each other or towards the other canines. On the other hand, the dog puppies were much more aggressive to each other and other canines, often seen full-on attacking their foster mother or one another.[42]

Dogs in human society[edit]

Further information: Human-canine bond

Research has shown that there are individual differences in the interactions between dogs and their human masters that have significant effects on dog behavior. In 1997, a study showed that the type of relationship between dog and master, characterized as either companionship or working relationship, significantly affected the dog's performance on a cognitive problem-solving task. They speculate that companion dogs have a more dependent relationship with their owners, and look to them to solve problems. In contrast, working dogs are more independent.[43]

Dogs in the family[edit]

Further information: Companion dog

Dogs at work[edit]

Service dogs are those that are trained to help people with disabilities. Detection dogs are trained to using their sense of smell to detect substances such as explosives, illegal drugs, wildlife scat, or blood. In science, dogs have helped humans understand about the conditioned reflex.

Attacks[edit]

Main article: Dog attack
A dog's teeth can inflict serious injuries

In the UK between 2005 and 2013, there were 17 fatal dog attacks. In 2007-08 there were 4,611 hospital admissions due to dog attacks, which increased to 5,221 in 2008-09. It has been estimated that more than 200,000 people a year are bitten by dogs in England, with the annual cost to the National Health Service of treating injuries about £3 million.[44] A report published in 2014 stated there were 6,743 hospital admissions specifically caused by dog bites, a 5.8% increase from the 6,372 admissions in the previous 12 months.[45]

In the US between 1979 and 1996, there were more than 300 human dog bite-related fatalities.[46] It is estimated that two percent of the US population, 4.7 million people, are bitten each year.[47][dead link] In the US in 2013, there were 31 dog-bite related deaths. Each year, more than 4.5 million people in the US are bitten by dogs and almost 1 in 5 require medical attention.[48]

See also[edit]

References[edit]

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