Sistrurus

A Herpetological Roundup: World Snake Day Edition

Posted on 16 Jul 2017 by Reptiles & Amphibians

It’s been a while since my last roundup, so there’s a lot to tell you about.

  1. Amphisbaenians—sometimes called worm lizards, though they’re neither, nor are they snakes—are the weirdest reptiles. And the mole lizards (Bipes) of Mexico, known locally as ajolotes, are the weirdest amphisbaenians, because while most amphisbaenians are legless, Bipes has forelimbs. Just forelimbs. You don’t see them very much because they’re so fossorial, but herpetologist Sara Ruane managed to catch one on video last month. Yes, it’s real. National Geographic has more.
  2. Speaking of legs, snakes still have the gene to grow them—the so-called “sonic hedgehog” gene. [Current Biology]
  3. It was long understood that snakes use the ZW sex chromosome system: the ovum determines the sex; males are ZZ, females ZW. Only a recent paper found that boa constrictors (Boa constrictor) and Indian rock pythons (Python molurus) have XY chromosomes—the sperm cell determines the sex, as it does in humans. [Current Biology]
  4. Ontario is extending Highway 400 toward Sudbury—through the territory of the threatened Eastern Massasauga Rattlesnake (Sistrurus catenatus). This CBC News article reports on the precautions taken by work crews as they work in massasauga habitat. Meanwhile, Lethbridge’s rattlesnake hotline—yes, they have a rattlesnake hotline—had a busy start to the summer.
  5. Turtle mortality along a stretch of road near Long Point, Ontario was so bad that local residents decided to do something about it. And after taking in nearly 600 injured turtles this year (up from fewer than 400 for all of 2016), the Ontario Turtle Conservation Centre, just outside Peterborough, has declared a “state of emergency” : they’re simply overwhelmed. Here’s a 2010 video from the Toronto Zoo showing how to help a snapping turtle cross the road.
  6. A turtle found wandering the streets of Burnaby, British Columbia turned out to be a threatened Wood Turtle (Glyptemys insculpta), which is not native to B.C. Showing signs of metabolic bone disease, the turtle was almost certainly an escaped or released pet kept illegally; it’ll be sent to a wildlife sanctuary in Ontario.
  7. The Guardian has the story of New Zealand’s cobble skink. The undescribed species was down to a few dozen individuals before wildlife officials tried to capture as many as they could before their habitat literally washed away. The entire population may now reside at the Auckland Zoo, awaiting reintroduction.
  8. Snake fungal disease has been found in more than 30 species in North America. Now it’s crossed the Atlantic: researchers have detected both the fungus and the lesions in wild snakes in both Great Britain and the Czech Republic. [Nature]
  9. Meanwhile, to prevent the spread of a fungal disease found in salamanders, the Canadian government has prohibited the importation of foreign salamanders, which will have an impact on the lab supply and pet trades. [Canada Gazette]
  10. In the Great Lakes region there are all-female populations of mole salamanders (Ambystoma) that are hybrids of several related species, e.g. the Blue-spotted (A. laterale), Small-mouthed (A. texanum) and Eastern Tiger (A. mavortium) Salamanders. A new study suggests that these female hybrids reproduce in a thoroughly curious manner: by mating with males from all three species, taking roughly equal parts of the donor males’ genetic material from each—a process called kleptogenesis. There are science fiction writers who’d have a hard time coming up with this. [Genome Biology and Evolution]
  11. Do snakes hunt in packs? A recent paper suggested that Cuban Boas (Chilabothrus/Epicrates angulifer) hunting bats in caves exhibit behaviour consistent with coordinated hunting. But David Steen is skeptical. “Snakes swallow whole. So when would ‘pack’ hunting be good? Only when there are lots of resources; no competition. Bat cave may qualify,” Steen adds on Twitter. [Animal Behavior and Cognition]
  12. Are snake bites on the rise? CNN’s alarmist headline and article gets smacked down.
  13. A question I answered on Quora: Why do snakes use constriction?

A Herpetological Roundup

Posted on 17 Apr 2017 by Reptiles & Amphibians

Mating group of Red-sided Garter Snakes (Thamnophis sirtalis parietalis), Narcisse Snake Dens, May 5, 2014.

  1. Spring is here, and the garter snakes (Thamnophis) are busily mating away — and that means mating balls where as many as a hundred frenzied males may be trying to woo a single female snake. That frenzy may be harder on the males than the females: a new study found that telomere length — associated with stress — decreased with males as they aged, but did not do so with females. [Proc. R. Soc. B]
  2. Then again, it could be worse: a photographer caught a female Green Anaconda (Eunectes murinus) in the act of constricting and eating its mate.
  3. Speaking of constriction. Kingsnakes (Lampropeltis) are known for eating other snakes, and they’ve also been known to eat snakes longer than they are — including other constricting snakes. They do it by constricting harder — twice as hard as rat snakes. [Journal of Experimental Biology]
  4. Ontario has banned the hunting of Common Snapping Turtles (Chelydra serpentina), a species that had previously been regulated as game wildlife (with seasons and bag limits). Conservationists have long argued that any take is unsustainable, and they’re right: turtles simply reproduce too slowly, and face too many other dangers (roadkill, nest predation) — they’re simply in too much trouble already.
  5. In other good news, the Arizona snake shot — allowing snakes to be shot within city limits — bill died in a tie vote in the state senate.
  6. Researchers at Grand Valley State University are monitoring a population of Eastern Massasaugas (Sistrurus catenatus); they hope to learn more to fight the onslaught of snake fungal disease, which is hitting the massasauga particularly hard.
  7. Oh, great: the purported medicinal properties of the Indian Sand Boa (Eryx johnii) has led to a spate of poaching and smuggling, putting the species, which is protected in India, at greater risk of extinction.
  8. India is also home to the unusual shield-tailed snakes (Uropeltidae), which Andrew Durso calls the “Darwin’s finches” of snakes.
  9. This January a rare species of boa, Corallus cropanii, endemic to Brazil’s São Paulo state, was found alive for the first time since it was described in 1953. It’s otherwise known from only a handful of specimens.
  10. Cobra venom is largely neurotoxic — it shuts down a prey animal’s autonomic nervous system — but some cobra venoms have cytotoxic, or tissue-destroying, qualities, most famously the venoms of African spitting cobras. Cytotoxins are painful but not as lethal as neurotoxins, so you’d think that cytotoxic venoms in cobras developed as a defense mechanism. But it turns out that cytotoxins don’t correlate with spitting, but with spectacular hoods: the more brightly banded or coloured a cobra species’ hood, the more cytotoxins in the venom. [Toxins]
Jonathan Crowe
Map blogger. Science fiction and fantasy critic and writer. Snake whisperer. Typewriter fiend.

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