Some links on venom, rattlesnakes, and rattlesnake venom:
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.
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]
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]
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.’”
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!)
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.
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.”
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.
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.
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.
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 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.)