Jonathan Crowe

Book reviewer, cat photographer, fanzine editor, map blogger, snake whisperer.

Category: Reptiles & Amphibians Page 3 of 4

A Venomous Roundup

Black-tailed Rattlesnake (Crotalus molossus), Little Ray's Reptile Zoo, December 20, 2008.

Black-tailed Rattlesnake (Crotalus molossus), Little Ray’s Reptile Zoo, December 20, 2008.

Some links on venom, rattlesnakes, and rattlesnake venom:

  1. In April, BBC Earth explored venom overkill — why are jellyfish, snake and other creatures far more venomous than they need to be, especially given the metabolic cost of producing venom? The answer is deceptively simple: “[t]here’s no such thing as absolute toxicity” — venom is tailored to specific prey that may have evolved resistance to it.
  2. Most North American rattlesnake venom lacks neurotoxins, but a recent study finds that their common ancestor did have the genetic ability to produce neurotoxic venom 22 million years ago. That ability has since been lost to specialization (see above): Western and Eastern Diamondbacks lost the ability to produce neurotoxins about six million years ago; Mojave Rattlesnakes, whose venom is neurotoxic, lost a myotoxin gene about four million years ago. [Science News]
  3. A 36-year study of a population of Timber Rattlesnakes in the Adirondacks found that female rattlesnakes waited, on average, until they were 10 years old before having their first litter, and that most had only one litter in their whole lives. This has serious conservation implications. [via]

A Herpetological Roundup

Prairie Ring-necked Snake (Diadophis punctatus arnyi), Harding County, New Mexico. Photo by Andrew DuBois. CC Licence.

Prairie Ring-necked Snake (Diadophis punctatus arnyi), Harding County, New Mexico. Photo by Andrew DuBois. Creative Commons licence.

Five (relatively recent) things make a post:

  1. BBC Earth on snake fungal disease: “In a few species snake fungal disease is having a truly devastating impact. ‘The main species I look at is a rattlesnake called the eastern massasauga,’ says Allender. ‘They have a 92.5% mortality rate from the disease.’”
  2. Wildlife biologist Andrew DuBois takes great photos of wild North American reptiles and amphibians. See his Flickr and Instagram accounts. I’m fond of the garter snake shots, of course, but the species coverage in general is quite comprehensive. (Spadefoots! Ensatinas! Thread snakes!)
  3. On Quora I answered a rather dumb question: How would you defeat a large snake that decided to attack you? “The short version: I wouldn’t need to, and if I did need to, I wouldn’t be able to.” Read on for the long version.
  4. Maclean’s asks what’s killing the animals at Calgary Zoo — they’ve had a rash of sometimes-bizarre deaths, most recently seven penguins. But one stood out, at least to me: “one zookeeper resigned after starving a corn snake to death.” I have kept and raised dozens of corn snakes. They’re the easiest snake out there.  As I said on Twitter, “if a zoo can’t keep a CORN SNAKE alive — something 8-year-olds manage to do all the time — that’s a serious red flag.”
  5. Many snakes, including hognose snakes and European grass snakes, feign death as a defence mechanism. I didn’t know that indigo snakes did it too — at their size, I didn’t think they needed to.

Savoie Acquitted in New Brunswick Python Case

Jean-Claude Savoie, the owner of the African Rock Python that killed two young boys as they slept in August 2013, has been found not guilty of criminal negligence causing death: Canadian Press, CBC News. The verdict comes after an eight-day trial that focused on a ventilation pipe the python escaped through, and whether Savoie was negligent in not securing it, or honestly believed the snake couldn’t squeeze through it.

New Brunswick Python Trial Begins

The trial of Jean-Claude Savoie, the former owner of an African Rock Python that escaped its enclosure and killed two young boys as they slept, begins today. The incident took place in August 2013 and was, to put it mildly, well-reported in the media (I even wrote an op-ed for the Ottawa Citizen about it.) Savoie was subsequently arrested and charged with criminal negligence causing death.

Hand-Feeding Wild Water Snakes

Tim Jones, a retired zoo director, has been hand-feeding the Diamond-backed Water Snakes (Nerodia rhombifer) that live in his private pond. The snakes have become so habituate to his presence that they’re comfortable taking food off his tongs. It doesn’t hurt that water snakes are rather food-motivated (which is a polite way of saying they’re extreme gluttons). You’ll note in the above video, along with shorter videos here and here, that they’re strongly directed by scent: if your fingers or pants smell like fish, it is by snake reasoning fish. Nom.

Now, Jones points out that this is a pond on private property; feeding wild animals is usually a no-no for very good reasons. You’d think that there would be little harm in habituating water snakes to human contact, or having them associate humans with food, and in a perfect world there wouldn’t be. It’s just that very few people would see an approaching water snake as friendly. Thwack. The end.

Some people might be surprised at the idea of tame water snakes, but I’m not. At one point, as some of you may remember, I kept three of them: two Banded Water Snakes (Nerodia fasciata) and a Northern Water Snake (N. sipedon), the latter under a provincial licence. They had insanely voracious appetites, but they were no less tame than any of my other snakes, and I put them to use in educational displays, where they wigged out people who believed water snakes were aggressive.

Basically, they’re just big garter snakes.

But mine were all born in captivity. That matters. It’s not reasonable to expect a wild animal to be friendly or tame: most will assume that a creature a hundred times their size is a threat to them. A snake has no idea that people are scared of it, or that being friendly and non-threatening toward people is a reasonable survival strategy. That’s counterintuitive.

Wild water snakes are bitey because they’re large enough for it to be a worthwhile defence strategy; smaller snakes of the same family, like brown and red-bellied snakes (Storeria), never bite, because there’s no point in doing so. Garter snakes are somewhere in between: some do, some don’t — it depends on the species, the individual and the circumstances.

Michigan Protects Five Reptiles and Amphibians

Michigan has added five reptiles and amphibians — Fowler’s toad, pickerel frog, mudpuppy, Butler’s garter snake and smooth green snake — to its animals of special concern list. The listing makes it illegal to kill or collect those species. That the Butler’s garter snake is included is significant: their lack of protection in Michigan meant that most specimens in captivity were originally collected there. (Mine certainly were.)

Extrovert, 1999-2016

Extrovert being weighed in 2015.

Extrovert, our female Wandering Garter Snake, finally died overnight. She’d been declining for months and we’d been expecting this for quite some time. She last ate on March 23rd, which was not immediately a cause for concern (she’d gone off her food before, in 2011 and 2014, but her appetite came roaring back in each case). But as the skipped meals piled up it became increasingly clear that this was probably it. We kept offering her food, just in case, but in the end it was the end.

Extrovert came into my hands on May 12, 2000. She was a well-started juvenile by that point, which meant that she’d been born the year before. That made her 17 years old when she died. Now, 17 years is a magnificent age for a garter snake. Not unheard of, but certainly not typical. She’s outlasted any other garter snake we’ve had, and a good number of the other snakes, too. Only four have been in our care longer than her.

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Facebook, Kingsnake.com and Reptile Hobbyists

The liberal political website Daily Kos has a piece on how Facebook has been wreaking havoc on independent website owners by drawing away both users and advertising dollars. They used as their example Jeff Barringer’s Kingsnake.com, which a decade and a half ago was the online reptile community website. That was a blast from the past: back then I spent an awful lot of time reading and commenting there, but I don’t think I’ve visited it at all in more than a decade.

It’s safe to say that most reptile hobbyists have migrated to Facebook. The mailing lists I subscribed to have been moribund for years, whereas I manage an active Facebook group with 2,500 members. What precipitated the move? I have a few guesses. For users, discoverability—everyone’s already on Facebook. And a Facebook group is turn-key: easy to set up, easy to use, already part of the ecosystem. You don’t need to buy web hosting or set up forum software. Also, reptile hobbyists are a fractious lot. A bunch of Canadian reptile hobbyists up and left Kingsnake.com’s Canadian site in a huff and started another site; then a bunch of that site’s users left it in a huff and started yet another site (which is still in operation, kind of). This diluted the authority of any one community website; no single site was compelling enough to have the stickiness necessary to go up against Facebook.

The end result is bad for independent site owners, who rely—or rather relied—on ad revenues that have long since dried up, and bad for the web ecosystem in general. It’s great for Facebook, of course, but it’s not necessarily bad for individual users. Let me be blunt: Kingsnake.com today looks a lot like it did in the late 1990s. Most independent reptile communities were not necessarily well-run in a technical or community sense. For users, Facebook can be an improvement—especially if Facebook is too busy delivering targeted advertising based on your personal data to care whether or not you should have to pay to post a classified ad.

The Seven Species of Milk Snake

At one point the Milk Snake (Lampropeltis triangulum) comprised two dozen subspecies ranging from Quebec to Ecuador, from drab, saddled snakes to brilliant tricolours, and from bootlace-sized minatures to six-foot behemoths. The difference between a local Eastern Milk Snake and a tangerine-morph Honduran Milk Snake from the pet store is pretty extreme. It had been suggested, I can’t remember where, that the Milk Snake was an example of a ring species, where neighbouring populations interbreed but the end points (i.e., Quebec and Ecuador) are too distantly related.

But the simpler answer is that these snakes are not all one species, and a recent study—an early draft of which I tweeted about in December 2013—suggests that they are, in fact, seven species. The authors divide them as follows:

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Snakes of the Southeast

There are a lot of regional field guides to reptiles and amphibians out there: I own at least two dozen of them myself, and I’ve reviewed several of them for herpetological newsletters. They perform yeoman service helping people identify the wildlife around them, which in areas with venomous snakes can be absolutely critical. But not every field guide is the same. Some really are field guides, to be used in the field to identify specimens: slim volumes that provide little more than range maps and identification keys. Others throw portability out the window in favour of comprehensiveness, providing hundreds of pages of scholarly detail between hard covers, but at a cost: they’re nearly inaccessible to the general reader.

snakes-southeastOne of my favourite field guides, Snakes of the Southeast, stakes out a middle ground. Though it’s written by two college professors, Whit Gibbons and Mike Dorcas, who co-authored a scholarly monograph on North American water snakes, it’s definitely aimed at a general readership — one that isn’t necessarily mucking about in swamps, but is nonetheless interested in the wildlife living in their region.1 More comprehensive than a slim pocket guide, but much more accessible than a scholarly reference, Snakes of the Southeast has a clear idea of what questions need answering and who’s asking them.

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