Is there a herpetologist in the house?
May 17, 2008 6:19 PM Subscribe
Do Gopher Snakes truly "imitate" Rattlesnakes or could they somehow be genetically related?
Growing up in northern California and being a Scout as a kid, I know all about the amazing ability Gopher Snakes (aka Bull Snakes) have of "imitating" the Western Diamondback by making a rattling noise through their nose, or with their tail in dry brush, hissing, the "S" posture, etc.
Recently, though, I got to thinking about which came first. Is it really all that likely that an animal would evolve such similar markings and the ability to mimic a *particular* other animal? It makes more sense to me, from an evolutionary point of view, that some distant cousin of both snakes had these behaviors. It was probably closer to the Gopher Snake, biologically, but at some point a branch diverged and the Rattlesnake was eventually born with a *real* rattle and venom to boot.
Has there ever been any study in to the Serpentes genome? Can anyone direct me to more information on evidence point in either direction?
Growing up in northern California and being a Scout as a kid, I know all about the amazing ability Gopher Snakes (aka Bull Snakes) have of "imitating" the Western Diamondback by making a rattling noise through their nose, or with their tail in dry brush, hissing, the "S" posture, etc.
Recently, though, I got to thinking about which came first. Is it really all that likely that an animal would evolve such similar markings and the ability to mimic a *particular* other animal? It makes more sense to me, from an evolutionary point of view, that some distant cousin of both snakes had these behaviors. It was probably closer to the Gopher Snake, biologically, but at some point a branch diverged and the Rattlesnake was eventually born with a *real* rattle and venom to boot.
Has there ever been any study in to the Serpentes genome? Can anyone direct me to more information on evidence point in either direction?
sorry, i hit post too soon.
i am pretty sure that there are many examples of animals evolving to imitate a particular other animal - examples which i bet include pairs of animals which are not at all closely related. surey someone will chime in.
posted by gcat at 6:29 PM on May 17, 2008
i am pretty sure that there are many examples of animals evolving to imitate a particular other animal - examples which i bet include pairs of animals which are not at all closely related. surey someone will chime in.
posted by gcat at 6:29 PM on May 17, 2008
Best answer: I can't speak to your particular question, but this is a well known phenomenon - Batesian mimicry. It gives an example of where an Owl (!) has mimicked a rattlesnake, so another snake doesn't seem too far fetched.
posted by scodger at 6:43 PM on May 17, 2008
posted by scodger at 6:43 PM on May 17, 2008
Rattlesnakes are pit vipers which and gopher snakes are not. Although they are "related" the species diverged a long time ago, long enough that pit vipers are found in Asia and N America.
So yep, the answer is that they developed the imitation behaviours independantly. It's a fascinating world out there.
posted by fshgrl at 6:43 PM on May 17, 2008
So yep, the answer is that they developed the imitation behaviours independantly. It's a fascinating world out there.
posted by fshgrl at 6:43 PM on May 17, 2008
By "species" I actually mean "groups of species that each of these particular snakes belong to"
posted by fshgrl at 6:45 PM on May 17, 2008
posted by fshgrl at 6:45 PM on May 17, 2008
I do know that gopher snakes are not the only snakes that do this behavior. Being a zookeeper I have seen prairie king snakes, indigo snakes, bull snakes and 2 different species of rat snakes all exhibit this mimicry when startled or threatened.
posted by fogonlittlecatfeet at 6:56 PM on May 17, 2008
posted by fogonlittlecatfeet at 6:56 PM on May 17, 2008
Best answer: One of these three is venomous, the other two are not:
Arizona coral snake
Mountain Kingsnake
Milk snake
(from) The others have evolved similar coloration because it scares away predators who have evolved to leave the coral snake alone.
posted by Class Goat at 7:38 PM on May 17, 2008
Arizona coral snake
Mountain Kingsnake
Milk snake
(from) The others have evolved similar coloration because it scares away predators who have evolved to leave the coral snake alone.
posted by Class Goat at 7:38 PM on May 17, 2008
fogonlittlecatfeet mentioned that many harmless snakes exhibit the behavior you describe; I have wondered if in fact the vibrating tail was the original behavior and rattles evolved to enhance it. Here is an article describing similar behavior in a legless lizard in Japan. As there are no rattlers in Japan, in this instance at least tail vibration did not evolve to mimic them.
posted by TedW at 3:22 AM on May 18, 2008
posted by TedW at 3:22 AM on May 18, 2008
Here is a family tree for reptiles; gopher snakes are colubrids, while rattlesnakes are vipers, so you can see about where they diverged in relation to the other big groups of snakes.
posted by TedW at 3:32 AM on May 18, 2008
posted by TedW at 3:32 AM on May 18, 2008
TedW: I believe there is a line of thinking out there along those lines. Colubrid lineages where rattle-less tail rattling occurs, i.e., lampropeltine snakes in North America, such as Lampropeltis (kingsnakes and milk snakes), Pituophis (bullsnakes, pine snakes, gopher snakes) and North American Elaphe (corn, rat and fox snakes), are, I believe, older than rattlesnakes. Pit vipers are a relatively young lineage, and rattlesnakes younger still. I remember reading something that suggested that rattles may have evolved in response to the presence of bison on the Great Plains: big honking hoofed animals that snakes didn't want to get stepped on by; a general lack of leaf litter, etc., to rattle your tail against.
(Colubrid tail-rattling is surprisingly effective in leaf litter or against wooden floors: I've had a few queries from people who are convinced they've seen a rattlesnake, when in fact they've seen a milk snake. These are people who've never seen a rattlesnake; they have no idea just how loud a rattlesnake's rattle is.)
Re: Batesian mimicry. I've also read that the similarities between some milk snakes and coral snakes is not a result of deliberate mimicry, but that they both may be examples of "startle coloration" -- i.e., they're both secretive animals that tend to burrow a lot, and when they're rousted they display a flash of colours that surprise the predator. The argument for this is that there are a lot of coral snakes that don't look like milk snakes and that there are tricolored milk snakes and mountain kingsnakes where there are no coral snakes -- i.e., that the correlation between model and mimic isn't perfect.
In the case of gopher snakes and rattlesnakes, I believe it's more a case that they occupy similar habitats, and have evolved similar coloration in response. Remember that snakes are in the middle of the food chain and must stay out of sight. You'll find that most snakes from the Rocky Mountains and Great Plains tend to share a yellowish-brownish-grey blotched pattern: hognose snakes, glossy snakes, rattlesnakes, bullsnakes and gopher snakes, night snakes, even wandering garter snakes. They look the same because they're subjected to the same Darwinian pressures.
Short answer: it's not that they're related, it's that they're neighbors.
posted by mcwetboy at 5:18 AM on May 19, 2008
(Colubrid tail-rattling is surprisingly effective in leaf litter or against wooden floors: I've had a few queries from people who are convinced they've seen a rattlesnake, when in fact they've seen a milk snake. These are people who've never seen a rattlesnake; they have no idea just how loud a rattlesnake's rattle is.)
Re: Batesian mimicry. I've also read that the similarities between some milk snakes and coral snakes is not a result of deliberate mimicry, but that they both may be examples of "startle coloration" -- i.e., they're both secretive animals that tend to burrow a lot, and when they're rousted they display a flash of colours that surprise the predator. The argument for this is that there are a lot of coral snakes that don't look like milk snakes and that there are tricolored milk snakes and mountain kingsnakes where there are no coral snakes -- i.e., that the correlation between model and mimic isn't perfect.
In the case of gopher snakes and rattlesnakes, I believe it's more a case that they occupy similar habitats, and have evolved similar coloration in response. Remember that snakes are in the middle of the food chain and must stay out of sight. You'll find that most snakes from the Rocky Mountains and Great Plains tend to share a yellowish-brownish-grey blotched pattern: hognose snakes, glossy snakes, rattlesnakes, bullsnakes and gopher snakes, night snakes, even wandering garter snakes. They look the same because they're subjected to the same Darwinian pressures.
Short answer: it's not that they're related, it's that they're neighbors.
posted by mcwetboy at 5:18 AM on May 19, 2008
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posted by vertigo25 at 6:21 PM on May 17, 2008