Jonathan Crowe

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

Tag: snakes

A Herpetological Roundup

Brown-snouted Blind Snake (Ramphotyphlops wiedii or nigriscens), November 13, 2015. Photo by Will Brown. Creative Commons Licence.

  1. Known from only a handful of specimens since its discovery in 1937 and feared extinct, the Albany Adder (Bitis albanica) was found alive and well—at least four specimens were—last November, in a South African location that is being kept secret to deter poachers. Because yes, poachers will collect the shit out of these snakes.
  2. The plan to reintroduce Timber Rattlesnakes (Crotalus horridus) to an island in the Quabbin Reservoir in Massachusetts has been suspended in the face of local opposition; the Worcester Telegram’s outdoors writer Mark Blazis is disappointed.
  3. Ontario Nature has announced its new and improved Ontario Reptile and Amphibian Atlas app, which isn’t so much an app as it is a mobile website that supports offline data. Anyway, it’s got a field guide and lets you enter species sightings.
  4. Fossil snakes are generally known from their vertebrae, which makes their study a little less exciting to the lay reader than dinosaurs; still, it’s rather exciting that a new extinct species, Zilantophis schuberti, has been described from a fossil found in eastern Tennessee. “Zilantophis bore uniquely broad wing-shaped projections on the sides of its vertebrae. In life, these were likely attachment sites for back muscles. These features are what inspired the name of the new genus, derived from Zilant, a winged serpent in Tatar mythology.” [Journal of Herpetology]
  5. Blind snakes (Scolecophidia) are tiny, secretive and easily overlooked; even so, there’s something of a blind snake renaissance going on, says Andrew Durso. “I recently noticed, much to my surprise, the the number of described species of blindsnakes has doubled in the last 13 years, from 305 in 2004 to 599 today; that’s 16.5% of all snakes! There are certainly many undiscovered species of blindsnakes, so it’s likely that their numbers will continue to grow.”
  6. A fascinating article in The New York Times Magazine from Daniel Engber that looks at the increasing use of the Burmese Python (Python molurus bivitattus) as a laboratory animal, and the possibility that its extraordinary digestive system—which has to flip from inactive to a 50,000-calorie meal all at once—may help find a cure for diabetes.

A Herpetological Roundup

Gray Tree Frog (Dryophytes versicolor), Mansfield-et-Pontefract, Quebec, July 11, 2010.

Five things make a post:

  1. New tree frog genus. North American (and a few Asian) tree frogs previously included in the genus Hyla — including Gray and Green Tree Frogs — have been moved to a new, sister genus, Dryophytes, thanks to a major revision of tree frog taxonomy (PDF). This follows other moves to split genera that spanned continents: Bufo (toads), Rana (true frogs) and Elaphe (rat snakes) have all been split up; North American toads are now Anaxyrus, North American true frogs are now Lithobates (except on the Pacific coast), and North American rat snakes are now Pantherophis. So this is not really a surprise move.
  2. Water snake outreach. The Lake Erie Water Snake (Nerodia sipedon insularum) remains on Canada’s endangered species list, but it was removed from the U.S. list in 2011, after a rebound in its U.S. population, which now numbers 10,000 adults. An invasive fish, the round goby, has something to do with it: the water snakes happily feed on them. But public outreach played a role as well. On Cool Green Science, the Nature Conservancy’s blog, Ted Williams looks at the outreach efforts of Dr. Kristin Sanford, whose research showed that habitat loss was less of a factor than human persecution. Her (now quite dated) website: Respect the Snake.
  3. Don’t shoot snakes. An Arizona bill that would lift a ban on firing a gun within city limits if it’s to shoot a rat or a snake is facing opposition — from people opposed to shooting snakes.
  4. Do snakes fart? Scientists are building an animal fart database, and yes, snakes are included. While passing gas might not be a good sign for an obligate carnivore, if by fart we mean making noise while defecating, I can attest that snakes certainly do. (With some of my larger and stinkier charges, I usually hear it before I smell it — at least if I’m in the same room.)
  5. Stressed snakes strike first. A snake’s background level of stress — rather than the stress of encounter, handling or confinement — may determine how likely it is to strike, according to a new study. [LiveScience]

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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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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Can Snakes Hear? (Hint: Yes)

Snakes are inscrutable and mysterious. That’s probably why so many people ask so many basic questions about their biology. (One I’ve run into a few times: do snakes have bones? The answer is yes, lots of them, but the question belies a confusion about what a snake is: they think it’s some variant of worm.)

Sometimes, though, the answer is complex, or incomplete because we don’t know yet. For example, last month, Andrew Durso looked at the science behind the question of whether snakes sleep, a question whose answer is made more complicated by snakes’ lack of eyelids. As it turns out, there hasn’t been a lot of work done on the subject (one EEG study with an African rock python). “So here’s what we know: snakes probably do sleep, perhaps most of the time, but we don’t really know when, for how long, how deeply, or whether or not they have paradoxical sleep, including dreaming.”

Now Andrew has posted another good question: can snakes hear? Now, those of us who know anything about snakes know that snakes don’t have external ears. It’s widely understood that snakes can feel ground vibrations, but airborne sounds? Much to my surprise, they can. This time there’s a bit more research. Snakes, it turns out, aren’t really deaf.

Studies have shown that snakes can hear sounds in the 80-600 Hz range optimally, with some species hearing sounds up to 1000 Hz (for comparison, the range of human hearing is from 20-20,000 Hz). This means that a snake could hear middle C on a piano, as well as about one octave above and two below, but neither the lowest key (which is 27.5 Hz) nor the highest (which is 4186 Hz). The average human voice is around 250 Hz, which means that snakes can hear us talking as well. Of course, there is likely a lot of variation among snake species, and the hearing of most species has not been examined, so these are generalizations.

Of course they don’t hear exactly the same way we do, because their inner and middle ears are structured differently. But now I’m wondering how much the snakes in our living room can hear the home theatre system. I’ve always assumed that they could feel the subwoofer, but it doesn’t look like they could hear it.

The Great Snake Weigh-in of 2015

This month Jennifer and I started doing something we’ve been meaning to do since the fall of 2013: weigh all the snakes in our menagerie. It’s something neither of us has ever done before; we’d had vague ideas of the approximate weights of our various critters, but that’s about it.

Our method was pretty straightforward: tare the scale, stick the snake on it, and take its picture. Those of you who follow me on social media will have seen the photos already; I’ve assembled them into a photo album here.

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