Talk:Agkistrodon piscivorus

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Good article Agkistrodon piscivorus has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
July 21, 2008 Good article nominee Listed
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Toxicity of venom[edit]

First sentence makes an assertion that the venom can be sometimes fatal. According to, at least one fatality has been reported, so this might make a good citation for that statement. —Preceding unsigned comment added by (talk) 23:48, 19 July 2009 (UTC)


I've found a source for wikipedia usable maps ( and I'll start stitching together the census line maps to produce a US map to use for species ranges.

These maps have been used on some pages already (which is how I found them). See Arlington County, Virginia for an example.

I don't know how far you've gotten on this, but I found some good PDF maps at the US Census Bureau, which are public domain. I cleaned up one of them to show state and county borders; no rivers and lakes, unfortunately, but it's a nice high resolution. Check it out. -- Wapcaplet 22:10, 20 Dec 2003 (UTC)


I'm no herpetologist or anything, but isn't that snake to the left of the description a copperhead?

No, I'm pretty sure that's a young cottonmouth. As juveniles these two species are very much alike, but according to Conant (1975), the main difference is that young cottonmouths have a dark postocular stripe (a line on the side of the head that descends from behind the eye to the angle of the jaw) and young copperheads do not. In the picture, you can just see a postocular stripe on the left side of the animal's head. --Jwinius 10:56, 31 May 2007 (UTC)
It's a cottonmouth. The young look very similar to ccopperheads, leading a lot of people to believe that coppers live in areas where they don't (like South Florida). Lfishel 05:23, 2 June 2007 (UTC)
This is true. These animals, in their youth, can look a *lot* like their smaller relative, the copperhead (_Agkistrodon contortrix_). The Southern Copperhead, _A. c. contortrix_, only ranges into a teeny bit of northern Florida, but I've known people in counties where copperheads aren't known to occur who have insisted that they had seen them there; invariably it turns out that the snake they saw was either a young cottonmouth or a colubrid (usually a watersnake of the genus _Nerodia_; I think these feisty but harmless animals may be responsible for the cottonmouth's reputation for aggression, since my impression has been that cottonmouths are shy, mellow snakes, reluctant to strike unless they've tried every other self-defence technique at their disposal, and not aggressive in the slightest).
One easy way to tell that a pitviper of the genus _Agkistrodon_ (copperheads, cottonmouths, cantils) is a juvenile is by the almost fluorescent greenish-yellow tail tip (about the colour of a tennis ball), used by the young snakes in caudal luring; if you're in Florida and you see a juvenile pitviper, consider the likelihood that it is a cottonmouth (the southern limit of the copperhead's confirmed range is Liberty County). Copperheads' colouration is typically more tan, sometimes even yellowish, although it may be reddish -- it evolved to blend in with leaf litter -- while newborn cottonmouths tend either to be very bright reddish-orange, or have a very pale background colour, sometimes with a pinkish tint (as in the picture) and dark brown or reddish-brown markings; they darken as they get older, so that the pattern on an adult cottonmouth may be barely visible (particularly among the Western race). Also, the Southern Copperhead (the subspecies that just barely enters Florida) usually just has saddle-shaped markings, often narrower than those of the Northern subspecies -- sometimes they actually don't meet in the middle, instead forming triangles on the snake's sides; juvenile cottonmouths usually have spots on the inside of and in between the bands, more like the markings typical of the Northern Copperhead (if anything the young cottonmouth's markings are more ornate than those of a Northern Copperhead). Note, however, that in the northern part of the cottonmouth's range, in the Carolinas and southeastern Virginia, the copperheads may be the Northern race (_A. c. mokasen_) or Northern-Southern intergrades, and may have some of the more elaborate patterning typical of the Northern race.
The two southwesternmost-ranging subspecies of copperheads, the Broad-Banded (_A. c. laticauda_) and Trans-Pecos (_A. c. pictigaster_) Copperheads, who reside in central and western Texas and Oklahoma, are easier to tell apart from young cottonmouths; these copperheads tend to be darker -- sometimes a very dark grey -- as juveniles, and instead of the saddle-shaped markings typical of the other races of copperheads, they have straight, wide bands (as suggested by the common name and species epithet of the former).
Cottonmouths may be identified easily if they choose to exercise their eponymous warning display, since the lining of a copperhead's (or a watersnake's) mouth is pink (about the same as a human's). There are other vipers and pitvipers whose mouths are white or pale pink on the inside (such as the Eyelash Palm Pitviper, _Bothriechis schlegelii_, of Mesoamerica), but none whose ranges overlap with that of the cottonmouth, that I am aware of. Mia229 (talk) 11:27, 12 September 2011 (UTC)

Cottonmouths in trees...[edit]

Young cottonmouths are occasionally seen in low bushes and I can't rule out one climbing a tree now and then, but certainly 99.9% of the "cottonmouths" seen basking in tree branches over water are harmless banded watersnakes (nerodia fasciata) or related species, the snakes most commonly mistaken for cottonmouths... I'm not sure what would constitute verification of this, since there are no doubt hundreds of people who swear they've seen it and the fact that no herpetologist or serious snake keeper has ever witnessed it and no one has ever taken a picture doesn't "prove" that it didn't happen. 21:08, 28 April 2006 (UTC)no they have not proved!!

One other thing, these snakes are located in Mississippi, as well. I do not know why that state did not get mentioned.

While it would be impossible to tell without catching and handling the snake (something i wouldn't do if i thought it was a cotton mouth) I'm 99% sure I've seen at least one drop from a tree branch right in front of me. It was dark with the correct colorations, very thick for it's length, and had the typical viper shaped head. It also swam across the top of the water like a cotton mouth. If it walks like a duck, looks like a duck, and quacks like a duck, it's probably a duck. I can also back-up the claim that they're not nearly as aggressive as people make them out to be. I've had friends pick up 4' cotton mouths with snake hook and we had to provoke it just to see the characteristic open mouth. —Preceding unsigned comment added by (talk) 18:02, 17 October 2008 (UTC)
If you happen to witness such a thing again, take a photo with your cell phone! Mia229 (talk) 16:08, 13 September 2011 (UTC)

Request: swimming picture of non-venomous watersnake[edit]

This page could benefit from a picture of a non-venomous watersnake swimming. Then readers could see the diference in how they swim, as this is a key way of distinguishing between cottonmouths and other watersnakes.JeffStickney 13:11, 15 October 2006 (UTC)

The article doesn't seem to include a picture of a swimming Cottonmouth either! Anyway, I have a picture I took in Nashville, TN (on the Harpeth river) in 2006. I was later told it was a Cottonmouth, although from this article, Nashville would be outside of the snake's natural range?
If it is indeed a Cottonmouth, perhaps we can include it as such. If it is a different and non-venomous watersnake, that would satisfy the original request!
(Not sure why the file is not embedding, so here's a link to the Wikimedia page.) --Chinmay7 (talk) 09:20, 28 September 2009 (UTC)

Copperhead as a common name[edit]

Are we sure that Copperhead is a common name for a Cottonmouth? I'm pretty sure it's not. —Preceding unsigned comment added by Jonjuan (talkcontribs) 17:22, August 29, 2007 (UTC)

According to Wright & Wright (1957), "copperhead" was at one point or another a common name used by some people to refer to A. piscivorus. That this name is usually used to refer to A. contortrix is beside the point. However, it is a good example of how confusing common names can be. --Jwinius 17:38, 29 August 2007 (UTC)

I live in the SouthEast (of North America) - in the area it's pretty common knowledge that we have three types of poisonous snakes: Rattlesnake, copperhead, and the water moccasin (aka cottonmouth). I would agree that there might be people that confuse two snakes (everyone gets the rattlesnake right), but I find it highly confusing to think that the three poisonous types of snakes are Rattlesnake, copperhead, and copperhead. Msull (talk) 03:33, 8 July 2008 (UTC)

Common names often refer to more than one species. It may be that A. piscivorus is generally referred to as the cottonmouth and that A. contortrix is generally referred to as the copperhead, but the point is that this is not always (or has not always been) the case. The list of common names here is simply as complete as I can make it given the available literature. I didn't make any of this stuff up: that's just the way it is. If you don't like it, go somewhere else. --Jwinius (talk) 10:16, 8 July 2008 (UTC)
There's no need to go somewhere else, maybe you could use more recent literature instead of studies from the early 20th century. There comes a point when it's more important to include correct information over cited information. Anyone who's written that the cottonmouth is also called a copperhead was misinformed, as the two snakes share the same range. It's not like when different regions used the same common name for two species, these two snakes share the same range so it would be incorrect to call both snakes which are found in the same place, the same name. Even Linneus mislabeled specimens, I would not put it past the author of the source you're referencing -- and it's not like you have to include it if there's doubt to it's authenticity.
When it comes to common names, there is no right and wrong. As opposed to scientific names, there is no governing body, such as the ICZN or ICBN that can vouch for their uniqueness, and there are no taxonomic authorities and can say whether they are currently valid or not. The only exception to this rule that I know of is the AOU that regulates common names for birds in North America. So, if in some old publications on snakes certain authors refer to this species as a copperhead, then there is no choice but to accept that as a fact. Just as important, if we add information from a source, such as Wright and Wright (1957), but leave out certain items just because we don't agree with them, then we are being selective with the truth, which is just as bad as corrupting it. --Jwinius (talk) 23:07, 18 October 2008 (UTC)

GA Review[edit]

This review is transcluded from Talk:Agkistrodon piscivorus/GA1. The edit link for this section can be used to add comments to the review.

GA review (see here for criteria)
  • It is reasonably well written.
a (prose):
  • "Large and notorious" - not a very precise way of putting this, notorious amongst whom? Notorious for what?
  • "It" - constantly repeated in the lead. Try interspersing "this snake" or "A. piscivorus" to break it up a little
  • Link or define "nominate subspecies" - technical term
  • "integradation" - undefined and unlinked technical term
  • "possibly extirpated" - a bit floridly-worded maybe just say "probably extinct"
  • "The population trend is stable. Year assessed: 2007" - merge into a single grammatical sentence.
  • "Constant persecution and drainage of wetlands" - unintentionally funny! Wetlands are not persecuted.
  • The huge list of food species is not particularly informative, might be better to summarise along the lines of "Frogs, newts, fish, snails.."
  • Lead fails to summarise the article, should at least touch on the main sections in the text.
  • Don't mix feet and inches, and cm and mm as units
  • cc is not a standard unit, millilitres are the direct SI equivalent.
a (references): Good
b (citations to reliable sources): yes
c (OR): no
  • It is broad in its coverage.
a (major aspects): yes
b (focused): yes
Fair representation without bias: yes
  • It is stable.
No edit wars etc.: yes
  • It is illustrated by images, where possible and appropriate.
a (images are tagged and non-free images have fair use rationales): Cottonmouth Snake, Gaping.jpg could swap to the FDA-gov tag
b (appropriate use with suitable captions): yes


On hold
Overall pretty damn good, just some tweaks needed. Nice work! Tim Vickers (talk) 03:58, 17 July 2008 (UTC)

So far, I've addressed almost all of your points, even to the extent of creating a new article: Intergradation. I guess the introduction can still be expanded, but I'm not in favor of summarizing the list of reported prey species: I believe it is informative, even to the extent of being entertaining! But, I'll admit that you probably have to be more into the subject to appreciate that level of detail. --Jwinius (talk) 21:21, 20 July 2008 (UTC)

OK, that's up to you. Very good work, congratulations! Tim Vickers (talk) 21:51, 21 July 2008 (UTC)

water moccasins[edit]

what can i do to get rid of water moccasins? how can i tell if it is indeed a baby water moccasins or not? please let me know it's very important, due to the fact that i've done killed two in my house and i have a 3 yr old son. —Preceding unsigned comment added by (talk) 22:10, 9 October 2008 (UTC)

Call an exterminator!! Though they probably won't attack unless provoked I wouldn't take my chances! —Preceding unsigned comment added by (talk) 18:10, 17 October 2008 (UTC)
Read the article. Most likely the snakes that you have encountered are not water moccasins at all and are probably harmless. --Jwinius (talk) 23:09, 18 October 2008 (UTC)
First of all, may I ask exactly where you live? I ask because I've known many people who thought they had encountered cottonmouths in locations that were outside the range of these snakes (including one in New England!). According to reverse lookup you are in central Texas, which is the westernmost edge of the cottonmouth's range, but if you are willing to tell me what specific metro area you live in I can probably find out whether there are cottonmouths there.

Wildlife rehabilitation (a volunteer service which should be listed in the phone book) should be able to identify whether they are cottonmouths or not. If the snakes are indeed cottonmouths, check under "wildlife" or "animal;" there should be a local service that can relocate them safely and humanely; these are more likely to have experience with snakes than an exterminator. I should mention that the cottonmouth that is dangerous is the one you don't see, and if you've seen them on your property, the chances are that you will continue to encounter them. You should be careful to watch where you step, and don't reach somewhere you can't see (like in a tree hollow, behind a rock, in deep grass, etc.); teach your child to be careful as well, and not to disturb a snake or approach it too closely (staying five feet away will be more than sufficient). Cottonmouths are not aggressive and will not attack a human unprovoked; even if they feel threatened, they are unlikely to strike without first trying other tactics such as crawling away, gaping, or spraying musk. I strongly recommend you not try to kill or remove cottonmouths or other venomous snakes yourself. A very large percentage of the venomous snake bites in the US are the result of people (usually young men) trying to catch or kill a snake (I've seen various statistics, between 40% and 90%, but it's definitely a lot). If you are finding snakes inside your house, there is a high likelihood that you have a rodent problem; dealing with this should cause the snakes to lose interest. Here is an article about snakebite by Prof. Whit Gibbons, an experienced herpetologist at the University of Georgia's Savanna River Ecology Lab:


Has anyone ever heard of these snakes being referred to as rattlers? Maybe by someone who calls all venomous snakes rattlers, but as these snakes have no rattle and have no audible warning, outside of hissing, I don't believe this is a common name for these snakes. —Preceding unsigned comment added by Eaglescout1984 (talkcontribs) 16:45, 3 June 2009 (UTC)

My understanding is that this term comes from the cottonmouth's habit of vibrating its tail when agitated--a trait shared with other poisonous and non-poisonous snakes. In shallow water, this in turn agitates the water or in leaves or other debris it makes a rustling sound. Pinethicket (talk) 12:59, 28 September 2009 (UTC)
Juvenile cottonmouths and copperheads also wiggle their tails i

According to Campbell & Lamar's _Venomous Snakes of the Western Hemisphere_, cottonmouths are or at one point were sometimes called "water rattlesnake," "mangrove rattler," or "saltwater rattler." I don't know if any of these names are still used. Pinethicket is right, they can make noise by wiggling their tails in water or leaf litter. Mia229 (talk) 16:08, 13 September 2011 (UTC)

Geographic range[edit]

The geographic range map show these snakes existing right up to the very edge of the border of the state of Kansas, but I am quite sure they do exist in that state, as my best friend grew up with a boy who was killed by multiple bites from these snakes (upon diving into a water-filled rock quarry), in approximately 1980. There is no other species of aquatic or semi-aquatic, venomous snake in the continental United States, so it had to be this snake. KevinOKeeffe (talk) 05:09, 19 June 2009 (UTC)

The geographic range map shows that these snakes stop in southern Missouri, however they are found in just about every pond, lake, river, and creek up here in northeastern Missouri as well. They are all over up and down the Mississippi and Missouri rivers, so its likely they are found in any state these 2 rivers run through. So I think its safe to say the current map is quit a bit off. —Preceding unsigned comment added by Ryu80x (talkcontribs) 03:43, 11 October 2010 (UTC)

I agree the map is too limited. I grew up in an area of metropolitan Atlanta that would be excluded from this map (at the time in a relatively undeveloped marshy suburb, now a concrete jungle), but had multiple run-ins with cottonmouths. I can also factually (though anecdotally) state that cottonmouths are, at least at times, quite deserving of their aggressive reputation. I was 'chased' (forced to back away very quickly and followed by a threatening snake) on two occasions. Taterbill (talk) 15:15, 20 August 2011 (UTC)

Introduction - reference to "approaching" intruders[edit]

It is common or tribal or pseudo knowledge that Cotton Mouths are aggressive. "Urban" (the term doesn't seem to quite fit here) legends have it that these snakes will approach and attempt to enter boats and have "chased" people and dogs.

The article does not really weigh in heavily on this issue, but does refer to the animals "approaching" intruders. The nearest citation to this statement, however, does not mention such behavior.

Given the variety of beliefs and statements on this aspect of Water Moccasin behavior, it would be helpful to strengthen this part of the article.

Pondhockey (talk) 05:42, 10 July 2010 (UTC) (Pardon my clumsiness and possible ignorance of etiquette; I'm new to this kind of discussion and editing.)


Here we go again! How about some unbiased writing not giving undue weight to a single study!

One study in 2002 found few snakes in the experiment to exhibit aggressive behaviors as defined by the researchers. That is NOT a finding that the water moccassin is not aggressive!

Did they test the aggressivenss near the nest or with young? Did they test while feeding or preparing to feed? Did they test in all seasons? Did they test both in the water and out of the water? Were they confirming prior studies or was this the first -still not duplicated- study? Furthermore, one sub-species could be more aggressive than others, but again, we just don't know, do we?

Not only that, the behavior reported by the study was different in repeated tests, with most snakes trying to escape in one study; and with most snakes adopting a defensive threat posture in another test!. What can really be concluded from this?

We also suffer from the inability to review the full text -freely- in order to evaluate -and criticize- the methodology. The bottom line is, Wikiteurs should not cite studies unless they cite reviews and not original research, which by definition is not yet the established body of knowledge -remember cold fusion?-

Clearly the wikiteurs have no clue about the scientific process to find the truth, as always evolving process. The paragraph should state instead that it is not settled whether the snake is aggressive and then cite representative studies or reports from both sides. This is what you do until a study is duplicated by others under the same conditions. Then you can conclude that, given the same conditions, i.e. temperature, humidity, lighting, season, maturity, etc., etc., what was reported can be generally accepted. Wikipedia is NOT a *Real* encyclopedia!

Disclaimer: This is a critique of a specific paragraph, not the whole article! (talk) 23:44, 25 February 2011 (UTC)

Completely agree. See my anecdotal post under Geographic Range above. *Something* can make them display aggressive behavior. Taterbill (talk) 15:17, 20 August 2011 (UTC)


"Harmless watersnakes of the genus Nerodia are often mistaken for it. These are also semiaquatic, thick-bodied snakes with large heads that can be aggressive when provoked,[5] but they behave differently. For example, watersnakes usually flee quickly into the water, while A. piscivorus often stands its ground with its threat display. In addition, watersnakes do not vibrate their tails when excited.[18] A. piscivorus usually holds its head at an angle of about 45° when swimming or crawling.[5]"

But it says earlier in the aggressiveness section that water moccasins usually swim away. What is the deal? Do they stand their ground or do they swim away? — Preceding unsigned comment added by Transkar (talkcontribs) 20:42, 27 April 2011 (UTC)

Latin words[edit]

The specific name is derived from the Latin words piscis and voro, which mean "fish" and "to eat".

Doesn't voro mean "I eat"? Paramecium13 (talk) 22:04, 4 July 2011 (UTC)

Technically "voro" can be either the first-person or stem form of the verb; you're right, it's not the infinitive ("vorare" is). "Piscivorus" is usually translated "fish-eater" [n.] or "fish-eating" [adj.].

Agression in this species (Agkistrodon piscivorus)[edit]

I am disturbed by this notation:

"Although their aggression has been exaggerated, on rare occasions territorial males will approach intruders in an aggressive manner" [3] Wharton, C.H. 1969. The cottonmouth mocassin on Sea Horse Key, Florida. Bull. Florida St. Mus., Biol. Sci. 14:227-272.

I would question this completely. Perhaps there needs to be clarification... My belief is that there needs to be a distinction between aggressive behavior on land or in the water.

I understand that anecdotes are forbidden in wikipedia archives... therefore I would leave it up to someone to research this and actually determine the aggressive nature of these snakes... but I would caution the EPA's statement that aggression "has been exaggerated". What exactly does it mean when something has been exaggerated? Is the EPA taking anecdotes and dismissing the aggression completely? That is certainly what the tone of the sentence is.

If anything, I would recommend that the statement from the EPA be scrapped completely unless an aggression study is actually done. From my own anecdote which occurred not even 20 minutes ago August 14, 2011 @ approximately 10:45 AM CST, I can tell you that cottonmouths are extremely aggressive on land. I wish I had made a video to record the "attack first" disposition of this particular cottonmouth... For the record, I live in Denton County Texas, next to lake Lewisville... to give some kind of geographical perspective... who knows... there are so many sleight variations of species based on location, it could be that the species in Florida is more "docile".

I am inclined to think, however, that there is a distinction between aggression on land versus water... the droughts here in TX means that cottonmouths probably have less water to reside; therefore they are forced onto land more frequently. There might be a connection between mobility and aggressive behavior. They are adept at moving in the water, but what about land? There may be a natural tendency for "fight" due to the fact that the land, for this species, is "unsafe" territory.

The Florida Cottonmouth (_A. p. conanti_) is a different subspecies than the Western Cottonmouth (_A. p. leucostoma_), which ranges as far as eastern Texas. It's possible there are differences in behaviour. Cottonmouths are semi-aquatic; they're as mobile on land as other pitvipers such as the copperhead, so I don't think that's it, but it may be that other adaptations for water (such as a preference for aquatic prey, although the species is also known for being willing to eat almost anything) make them more comfortable there and so the drought is leading to increased desperation to flee. It is true that the species is almost always found in or near water. Mia229 (talk) 16:31, 13 September 2011 (UTC)


I found this article regarding the aggressive behavior of the cottonmouth... Here is the citation:

<ref>Means, Bruce. "Blocked-Flight Aggressive Behavior in Snakes". IRCF ReptIles & AmphIbIAns • Vol 17, no 2 • JUn 2010. Retrieved 14 August 2011. </ref>

This is a great article and explains exactly what happened with me and the cottonmouth I encountered. Dr. Means is calling this "blocked flight aggressive" behavior. An excellent article on the aggressive nature of this snake and other snakes. It's a great find.

— Preceding unsigned comment added by Blaine72 (talkcontribs) 16:32, 14 August 2011 (UTC) 
Yes, I remember this report; Dr. Means refers to the behaviour as "shammed aggression," or "bluffing aggression," since the intent is clearly defensive and in any case is hardly unprovoked. (If I were the snake, I would certainly consider preventing me from escaping a provocation, especially if the one doing the blocking is a big scary human-monster. :->)
It's rare to happen upon a cottonmouth with her babies, as the young pitvipers only stay with their mother for a short time (about 2 weeks max). Mothers of other species of pitvipers, and other viviparous snakes such as boa constrictors, have been known to cover for their newborns by making false strikes while the young retreat to safety (up a tree, into a burrow, etc.), though. (I don't know whether any oviparous snakes do this too, although I would expect it at least in the case of oviparous pitvipers such as the bushmasters (_Lachesis_) and Malayan pitviper (_Calloselasma rhodostoma_), and perhaps pythons (which also brood their eggs).
I would say the EPA is correct that aggression "has been exaggerated," although I agree that this statement is rather ambiguous; I'm dubious as to whether this bluffing behaviour (which is, as Dr. Means makes clear, *not* an actual attempt to bite) even ought to be considered "aggression," but even if it is, Dr. Means seems to be right that it only occurs under particular circumstances, does not appear to pose any threat of a bite, and probably can be avoided simply by letting the cottonmouth go on its way rather than blocking it. The rumoured "aggression" by cottonmouths is, in any case, much more extensive than that which has been documented reliably. The EPA didn't rule out aggression, though, they just said that rumours have exaggerated it. Mia229 (talk) 16:08, 13 September 2011 (UTC)