Jonathan Crowe

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

Tag: snakes (Page 1 of 2)

Thirsty Snakes

Snakes need to drink—though that fact does come as a surprise to some people. (And it can be neat to watch, in the sense that a snake doing an ordinary thing that every other terrestrial vertebrate does is somehow a revelation.) But it does mean that they can get dangerously dehydrated when they can’t. They’ll even accept water from people if it’s hot and dry enough, as a couple of incidents recently reported on social media will demonstrate.

During Mark Lotterhand’s visits to the Narcisse Snake Dens last month, Manitoba was in the middle of a spring drought. When they set out water from their bottles, the Red-sided Garter Snakes came running, drinking from makeshift water holes, lids filled with water, or even directly from the bottle.

See Mark’s photo album on Flickr.

Getting garter snakes’ minds off mating in the middle of mating season takes some doing, let me tell you, but snakes coming out of hibernation are pretty thirsty to start with: they might not have had anything to drink in months. Add to that dry conditions and they must have been desperate for the water.

Meanwhile, on a hot June day in Illinois, two field research assistants, in the course of their fieldwork, found a Western Hognose Snake; once the snake was measured, they thought that the snake might be dehydrated, so they offered her water. The snake, who had previously exhibited the usual hognose snake defensive repertoire, thought this was a grand idea.

That tweet went viral, so one of the assistants, Taylor West, gives the background to the story in this guest post on the Living Alongside Wildlife blog.

Eastern Hognose Snake (Photo by Douglas Mills)

A Herpetological Roundup

  1. The U.S. Fish and Wildlife Service has listed the Louisiana Pine Snake (Pituophis ruthveni), found only in Louisiana and Texas, as a threatened species under the Endangered Species Act. The snake, one of the rarest snakes in the U.S., had been classified as endangered on the IUCN’s Red List of Threatened Species in 2007.
  2. CBC News looks at how researchers are tracking the Eastern Hognose Snake (Heterodon platirhinos) in Ontario, where it’s a threatened species. (It’s not, however, rare elsewhere: it’s classed as “least concern” on the IUCN Red List.)
  3. On that note, how many times are conservation efforts focused on a nationally rare population of something widespread and abundant elsewhere (such as, for example, Eastern Hognose Snakes in Ontario) or a rare subspecies or population of a very common species (San Francisco Garter Snakes)? The Zoological Society of London’s EDGE of Existence program focuses “specifically on threatened species that represent a significant amount of unique evolutionary history.” The New York Times looks at the reptiles on the program’s list. [PLOS One]
  4. Still with the New York Timesa long article by Rachel Newer looks at a loophole in the exotic animal (especially reptile) trade: traffickers are laundering wild-caught animals through local farms so as to export them with paperwork certifying them as captive-bred—at which point authorities can’t do anything about it. Worth the read: a balanced look that explores some uncomfortable issues.
  5. Cottonmouths (Agkistrodon piscivorus) have a reputation for being belligerent snakes. Field trials suggest that baseline stress levels are a better predictor of whether a cottonmouth will strike than the stress of encountering an individual human being. Which is not to say that humans aren’t stressing cottonmouths out; it’s just happening at the habitat level, not on an individual basis. [General and Comparitive Endocrinology]
  6. Researchers at Carleton University studying the mating habits of Northern Map Turtles (Graptemys geographica) wondered whether males preferred larger females (female map turtles get much larger than males). So they 3D-printed up some female turtle sex dolls, set up a video camera, and watched what happened. [Animal Behaviour]

  1. Ranavirus has spread to Ontario turtles, which is not good. (See also CBC News.) To minimize the spread of Ranavirus and other herpetofaunal pathogens, here is the decontamination protocol for those working with reptiles and amphibians in the field.
  2. All turtle species in Ontario are now at risk, says Ontario Nature, though that statement takes some unpacking: COSEWIC listed the Ontario and Quebec populations of the Midland Painted Turtle (Chrysemys picta marginata), as well as the Quebec, New Brunswick and Nova Scotia populations of the Eastern Painted Turtle (C. p. picta) as Special Concern; but the Prairie and Ontario populations of the Western Painted Turtle (C. p. bellii) are still listed as Not at Risk. (The Western Paint is still in trouble in British Columbia, though.)
  3. Whatever the conservation status, turtles face long odds and need all the help we can give them. This video from the Nature Conservancy of Canada, on what to do when you see a turtle on the road.

  1. The chytrid fungus implicated in the decline of amphibian populations worldwide has had its origins identified: the Korean peninsula some time in the early 20th century. The Korean War may have been a vector. [Science]
  2. Finally, and because this roundup needs some levity, the Axolotl (Ambystoma mexicanum). It’s an ambystomatid salamander like the spotted and tiger salamanders, but this deeply weird (and critically endangered) denizen of Mexican lakes remains in its neotenic state throughout its life, only changing into its adult form if it’s induced by administering iodine or the thryoxine hormone. In 2015, the Rathergood comedy team came up with a song about the Axolotl, which they cleverly called “The Axolotl.”

Questions I’ve answered on Reddit recently:

Featured image: Eastern Hognose Snake (Heterodon platirhinos), Missouri, May 11, 2017. Photo by Douglas Mills. Creative Commons licence.

Springtime for Garter Snakes

It’s not spring until the garter snakes come out of hibernation. And after a winter that seemed longer and more brutal than usual, we finally got spring last week.

Last Tuesday, some of Jennifer’s students pointed her to a site near the school where Eastern Garter Snakes (Thamnophis sirtalis sirtalis) were emerging from hibernation. And when I say pointed her to, I mean told her about it by handing her a bunch of wriggling snakes, because the kids know her. The kids released the snakes where they found them, but she told me about it and we made a note to check the site out after classes were done.

The location the kids told her about was at the edge of some seriously snakey habitat: lots of ground cover, and next to a wetland that was already echoing with the calls of Wood Frogs (Lithobates sylvaticus) and Spring Peepers (Pseudacris crucifer). Which is to say, snake food. A good spot, in other words. But in our initial search we only found one snake, which musked all over Jennifer. It took us a while to find the entrance to the hibernaculum, the precise location of which I will not reveal here to ensure the snakes’ safety and privacy, but once we did we found the area fairly crawling with snakes. I had brought my Nikon D7100 with me and took some pictures.

Read More

A Herpetological Roundup

Featured image: Freshwater Crocodile (Crocodylus johnsoni), Little Ray’s Reptile Zoo, May 2013.

  1. How do you tell the difference between an alligator and a crocodile? Usually the answer has something to do with snouts and teeth. Add another difference: alligators and caimans have shorter foreleg (humerus) and hind leg (femur) bones than crocodiles. Crocodiles can gallop—alligators not so much. [Royal Society Open Science]
  2. 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]
  3. 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.)
  4. 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.
  5. The Turtle Conservation Coalition has released a report highlighting the most endangered tortoises and freshwater turtles. A lot of the “25+” most endangered species are in southeast Asia, as you might expect, but not all of them are. The 68-page report, titled Turtles in Troublecan be downloaded as a PDF here.

Questions I’ve answered on Quora in the past month:

A Herpetological Roundup

  1. Fix and Release” is a 15-minute CBC documentary on the Ontario Turtle Conservation Centre’s work rehabilitating injured turtles. [YouTube]
  2. More signs that reptile population locations are being obscured or hidden to keep the animals from being poached or killed: scientists released 6,000 eastern spiny softshell (Apalone s. spinifera) hatchlings near London, Ontario, but the location is being kept secret.
  3. Here’s a short video on building a snake hibernaculum on your property, hosted by two friends of mine: Jeff Hathaway (of Scales Nature Park) and Ben Porchuk, whom I met while messing about on Pelee Island.
  4. Dozens of snakes—western fox snakes (Pantherophis ramspotti) and racers (Coluber constrictor)—were rescued from a well scheduled to be demolished.
  5. 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 NewsToronto Star]
  6. 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]
  7. 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]
  8. 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]
  9. 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.
  10. Finally, here’s video footage of a western diamondback rattlesnake (Crotalus atrox) riding on the back of a tortoise. Yee-haw. [UPI, YouTube]

A Herpetological Roundup

Turtle-headed Sea Snake (Emydocephalus annulatus), Okinawa, Japan, July 2011. Photo by Klaus Stiefel. Creative Commons Licence.

  1. The Christian Science Monitor reports on how the residents of the town of Glastonbury, Connecticut learned to live with—and help protect—the endangered Timber Rattlesnake (Crotalus horridus).
  2. When cicadas emerge, they’re a plentiful food source for many species—including, as the Houston Chronicle’s Shannon Tompkins learned, Copperheads (Agkistrodon contortrix), which aggregate in large numbers and stuff themselves silly.
  3. 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]
  4. 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]
  5. When it comes to invasive reptiles in Florida, Burmese Pythons get all the press, but they’re not the only ones; CNAH lists 65 alien reptiles and amphibian species introduced to North America, most in Florida. Three of those species are chameleons. As invasive species go, they’re pretty innocuous, but still. National Geographic has a look at Florida’s chameleon hunters, who adopt out the chameleons they catch.
  6. Meanwhile, across the Straits of Florida, the Washington Post looks at an unlikely refuge for rare snakes like the Cuban Boa (Chilabothrus/Epicrates angulifer): Guantanamo Bay.
  7. A Manitoba couple caught a Plains Garter Snake (Thamnophis radix) in the act of gobbling down an Eastern Tiger Salamander (Ambystoma tigrinum). Small problem: the salamander’s endangered. That snake is in serious legal trouble.
  8. 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]

A Herpetological Roundup: World Snake Day Edition

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?

Snakes of the Eastern United States

The short version of this review: remember Snakes of the Southeast, the field guide by Whit Gibbons and Mike Dorcas, the second edition of which I reviewed last year and thought so highly of? Well, now Gibbons has done the same thing, only covering the entire eastern United States, with (appropriately enough) Snakes of the Eastern United States (University of Georgia Press, April 2017). Go get it.

But maybe I should expand on that a bit.

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.

Amazon

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]

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