Evidence of parental care in snakes does exist, but it’s rare and tantalizing. Here’s another data point. Python mothers are already known to incubate their egg clutches: while cold-blooded, they can raise the temperature of their clutch through muscle movement. A new study finds that Southern African Rock Pythons (Python natalensis) also stay with their young for the first two weeks after their eggs hatch. (Much like rattlesnakes have been observed doing.) [Journal of Zoology]
Audubon magazine looks at efforts to reintroduce the Eastern Indigo Snake (Drymarchon couperi) into its former range, and asks a very Audubon question: what is the impact of this on songbirds? (Indigo snakes are snake predators: feeding on nest raiders like rat snakes can reduce predation on songbirds.)
No surprise: “The European Union is a major destination for illegally smuggled live snakes, lizards and tortoises from southern Africa, posing a serious threat to their conservation.” From what I heard when I was more active in the trade, Europeans have a reputation for smuggling everything from everywhere: they have all the species, just don’t ask too many questions about how they got them.
Last month a Peterborough, Ontario man was bitten by a monocled cobra (Naja kaouthia) and had to be given given antivenom from the Toronto Zoo’s stock at Scarborough and Rouge Hospital. [CBC News, Toronto Star]
The Calabar burrowing python (Calabaria reinhardtii) is an unusual egg-laying boa from central Africa. It’s a nest-raider that feeds primarily on baby rodents. Mama rodents tend to have a thing or two to say about that, so it turns out that Calabaria has an extraordinarily thick skin that resists penetration (i.e., from bites)—thicker and tougher than any other snake they compared it to, causing researchers to call it a “rhinoceros among serpents.” [Journal of Morphology]
Climate change may be making bearded dragons (Pogona vitticeps) dumber. The National Geographic headline is a bit clickbaity; the underlying study suggests that incubation impacts social cognition. “Lizards incubated at colder temperatures were quicker at learning a social task and faster at completing that task.” The study determined that the effects of incubation temperature lasted into adulthood. The effect of rising global temperatures follows from that. [Royal Society Open Science]
Last week the New York Times reported on snake fungal disease, which has featured prominently in previous posts. A new study suggests that in the eastern United States snakes afflicted by the fungus “are both phylogenetically and ecologically randomly dispersed”—i.e., widely different species in widely different habitats—and that monitoring “should consider that all snake species and habitats likely harbor this pathogen.” This is, as they say, bad. [Science Advances]
Paul “Little Ray” Goulet is another old friend, and the proprietor of Little Ray’s Reptile Zoo in Ottawa. For the past few years he’s been offering free passes over the holidays to disadvantaged families who’d otherwise be unable to afford to go to the zoo. (Zoos, whether private or public, are a lot more expensive than they used to be.) Here’s the Ottawa Citizen story.
Neil Balchan is upset, and so am I. The garter snake researcher visited a wintering den where he was doing field research only to discover that dozens of harmless red-sided garter snakes had been beaten and butchered at the site. CBC News has more.
Here’s TVO on the fragile state of the eastern hognose snake in Ontario.
Tiger keelback snakes are both venomous (it’s a rear-fanged colubrid) and poisonous, thanks to the toads they feed on. The snakes store the toad toxins in their nuchal glands. But do they know they’re packing toad toxins? According to a new study, yes: the snakes’ defensive behaviour changes depending on the toxicity of their diet. [Journal of Comparative Psychology]
Sean Graham has some advice for field herpers: instead of spending money and effort on finding rare species for your life list, they should spend that on field work that might actually do some good. “Imagine if instead of trying to find their lifer Pigmy Rattlesnake in Apalachicola National Forest, they instead went looking for them in central Alabama where records are few and patchy? If instead of herping for fun, everyone made their herping count?”1
Using the Internet to identify snakes is definitely a thing; I’ve gotten my share of requests. Sierra, the Sierra Club’s magazine, looks at how the Snake Identification Facebook group does the job. Turns out the challenges the group faces are as much about social dynamics—dealing with frivolous requests, not attacking people for killing snakes—as they are scientific.
Pollution is turning sea snakes black. The Turtle-headed Sea Snake (Emydocephalus annulatus) normally has a banded pattern (see above), but individuals found in polluted waters around New Caledonia are increasingly melanistic. It’s a phenomenon called “industrial melanism”: melanin tends to bind to metal ions of trace elements like arsenic and zinc; melanism and an increased shed cycle allows these snakes to rid themselves of toxic metals. [Current Biology]
Speaking of sea snakes, say hello to the Yellow Sea Snake (Hydrophis platurus xanthos), a newly discovered subspecies of the Yellow-bellied Sea Snake that is found in the warm, turbulent, anoxic waters of Golfo Dulce, off the Pacific coast of Costa Rica [Zoo Keys]
And what is almost certainly the weirdest reptile story ever to come to my attention: a story about turtle boners. No wait, it’s better than you think! It’s really difficult to figure out a turtle’s sex. So researchers came up with the idea of—oh boy—using a vibrator to stimulate the turtle: male turtles would get an erection. So: turtle boners. In the study, the method had a 100 percent accuracy rate. Because: turtle boners. Science is awesome. That is all. [Acta Herpetologica]
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.
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]
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.
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.
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.
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]
What impressed me about Snakes of the Southeast is that it knew its intended audience: not scholars, not hobbyists, but the general public. And in pitching itself at that audience, it knew what questions needed answering. As I said in my review last year:
The core of the book, the species guide, is detailed but plain-spoken, and does not drown the reader in scholarly references. It’s beautifully laid-out, with full-colour range maps and photographs of the region’s snakes. Its identification guide eschews the detailed scale counts used by professional herpetologists in favour of emphasizing distinctive traits and other factors more easily recognized by amateurs. And with two additional chapters explaining basic snake biology and exploring the relationship between snakes and humans, Snakes of the Southeast becomes a one-book solution: the book that tries to cover all the bases and answer all the questions about snakes that someone in the region might reasonably have.
Snakes of the Eastern United States follows that prescription down the line, which is no surprise given that it shares an author and a publisher with the previous book. The many virtues of Snakes of the Southeast, above and beyond being a species guide, are now accessible to people from outside that region. I’ve got a book I can recommend to more people.
In terms of its function as a species guide, as well as on field guides in general, though, I have a few thoughts.
Once again, this book takes an extremely conservative position on snake taxonomy. Rat snakes, for example, are called Pantherophis instead of the old Elaphe, but the traditional subspecies are maintained “because in most cases ratsnakes from particular geographic regions are easily identifiable based on color and pattern” (p. 198). Neither does Gibbons separate out the Common Kingsnake (Lampropeltis getula) into separate species, nor adopt the more recent taxonomic changes to swamp, crayfish and milk snakes. One gets the impression he sees these changes as for change’s sake.
Regional field guides have interesting edge cases, especially when they’re defined by political boundaries (a country, state or province) that don’t necessarily line up with bioregions: there’s always something atypical living in the borderlands. Gibbons defines the eastern United States as every state east of the Mississippi, excluding Minnesota but including Louisiana. So in this case we get central and western species like the Western Worm Snake (Carpophis vermis), Western Hognose Snake (Heterodon nasicus), Great Plains Rat Snake (Pantherophis emoryi) and Lined Snake (Tropidoclonium lineatum) at the edges of Gibbons’s maps. Illinois is usually the culprit.
(Speaking of maps: the map for the Butler’s Garter Snake [Thamnophis butleri] doesn’t include its Wisconsin range—a surprising omission given its politically charged status in that state.)
Then there’s the question of how the species are organized. This is actually an important consideration when the guide covers a large area or a large number of species. Some guides, simply list them in alphabetical order after sorting them by family (e.g. boas, colubrids, pit vipers) or separating the nonvenomous from the venomous snakes: this is the approach taken in Ernst and Ernst’s Snakes of the United States and Canada, Rossi and Rossi’s Snakes of the United States and Canada (no relation), and Werler and Dixon’s Texas Snakes. Others, like Alan Tennant in his state and regional field guides, categorize them in some fashion, e.g., small snakes versus aquatic snakes versus large terrestrial snakes.
Gibbons takes the latter approach, which necessitates some odd judgment calls, like splitting the kingsnakes between the midsize and large terrestrial snakes categories, or putting the closely related (and not that different in size) Short-headed Garter Snake (Thamnophis brachystoma) and Butler’s Garter Snake in the small and midsize categories, respectively. It’s the edge cases that’ll get you every time.
But these are quibbles, and there are always quibbles in books like these, which involve the compilation of a huge amount of field data, scientific knowledge, photography and text that must somehow come together in a whole that is not only coherent, but readable. This book achieves that end result far better than most.
I received an electronic review copy of this book via NetGalley.
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.
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.
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]
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.”
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.
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]
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.
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.
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]
So our 10-year-old female Okeetee corn snake, variously known as Little Miss Adorable, LMA and Ella Mae, started laying infertile eggs yesterday.
This is not unheard of — our female bullsnake, Lucy, and our leucistic Texas rat snake, Snowflake, have done this once or twice — so while we were surprised (February is really out of season for this sort of thing), we were not completely unprepared. Egg binding can be a thing, so we threw together a nesting box full of sphagnum and vermiculite, and then a larger box of sphagnum and vermiculite because her cagemate, Pretzel, wanted to curl up in there as well.
This does explain her recent behaviour: missing the last two or three meals (unheard of for a corn snake, except when gravid), restlessly pacing her cage and upending the furniture (much to the annoyance of Pretzel, who is twice her age and much more seclusive).
Five eggs so far, all infertile — she’s never so much as shared a cage with a male snake, and for good reason: corn snakes are the second-friskiest snake species known to captive husbandry. This is much to the annoyance of the (aptly named) Trouser, the male corn snake who lives in the next cage, who I suspect has been slowly going nuts about living next to two female snakes for years. But when I kept Pretzel and Trouser in the same cage, she would hollow herself out laying eggs that turned out to be infertile. The only surefire way to keep corn snakes from breeding is to segregate them by sex.
All things considered, infertile eggs — or, in the case of live-bearing snakes like garter snakes, egg masses — are a pretty rare occurrence. Caught us off guard this time, it did.
Update, Feb. 17: As of yesterday, LMA has laid an additional six eggs, for a total of eleven. Her backside looks appropriately hollow and she’s entered her post-egg-laying shed cycle, so we can stand down with respect to the risk of egg binding. There’d been some worry about that for a while: at one point it looked like had an egg just above the vent that was not going to pass.
Atlas Obscura on the comeback of the only remaining rhyncocephalian, the tuatara (Sphenodon). Breeding programs having more tuataras than they know what to do with is a nice problem to have. (I know people who, through zoo connections, have handled tuataras. I’ve never so much as seen one in the flesh.)
Kenya has banned the export of various snakes, including the African Rock Python (Python sebae), due to the impact of collecting and poaching on wild populations. I would have thought that there wouldn’t be much demand, relatively speaking, for the large and nasty African Rock Python, but they’ve been collected so much that, like overfished species, their full-grown size in the wild has diminished. [via]
A plan to reintroduce the Timber Rattlesnake (Crotalus horridus) to an island in the Quabbin Reservoir in Massachusetts is running into opposition from local residents, though the island is a more isolated and remote reintroduction site than just about any other alternative. [via]
The Mexican Garter Snake (Thamnophis eques) is endangered in Arizona, so residents presumably still can’t shoot it. It was believed to have disappeared from the Colorado River system, but it was recently spotted near Lake Havasu City, which has wildlife officials scratching their heads a bit. [via]