A few weeks ago, one of our two male Red-sided Garter Snakes (Thamnophis sirtalis parietalis) — the last of the great litter of 2002 — decided to bite himself, at which point he recoiled in alarm and surprise. He and his brother are curious and friendly (albeit very ravenous: they’ll bite your fingers, though it’s not personal; they’re just hungry), but they’re just not very smart.
By no means is that the first time I’ve seen one of my snakes bite itself. Normally it’s something I associate with Common Kingsnakes (Lampropeltis getula); I recall seeing both California and Speckled Kingsnakes chew on themselves. Apparently it’s more than a kingsnake thing.
Last week, though, I was summoned to answer a question on Ask MetaFilter from someone whose son’s California Kingsnake chewed on its own tail on more than one occasion. You can read my answer there; I’m going to flesh it out a bit more (and organize it a bit better) here.
You’ll note that in the above image from Wikimedia Commons by Nobo Tamura, it’s shown eating a small theropod dinosaur — because ancient creatures that could (or did) eat small dinosaurs are inherently interesting for some reason.
Beelzebufo will look familiar to people who know their frogs, because it was a ceratophryine frog: South American horned frogs, sometimes sold as “Pac-Man frogs” in the pet trade, and known for their general belligerence and willingness to nom. But Beelzebufo was different: it was larger, of course; but it lived 65 to 70 million years ago — in Madagascar, and ceratophryines were thought to be native to South America.
As a result, Beelzebufo’s discovery is significant in terms of the timing of the breakup of the Gondwana supercontinent. South America and Madagascar were parts of Gondwana that were isolated from the rest of the world, biologically speaking, until relatively late. India and Africa met Eurasia tens of millions of years ago, but the Great American Interchange only occurred three million years ago when the Panamanian isthmus formed. Prior to that point, South America maintained some deeply weird fauna, some of which is still around.
The neat thing is that there is at least one other group of animals found only in relict areas of Gondwana: boas. More specifically, true boas, such as boa constrictors, rainbow boas, and anacondas. Boas moved into Central America, Mexico and the Caribbean during the Interchange, but they’re also found in Madagascar and Réunion (such as Dumeril’s Boa) and on certain islands in the Pacific (Candoia). There were probably true boas elsewhere in Gondwana, but they’ve since been displaced by pythons.
Compare a boa constrictor and a Dumeril’s boa, and you’d be hard pressed to guess that they were separated by thousands of miles and tens of millions of years of isolation. And they’re not the only ones.
Salmonella infections can be a concern for reptile keepers, but I don’t think many of us would have considered the frozen mice and rats we keep as snake food as a potential disease vector. That’s apparently the case, according to an article in today’s New York Times. Mail-order reptile food supplier MiceDirect has issued a voluntary recall of frozen mice, rats and chicks due to potential Salmonella contamination. According to the Times, some 400 people in the U.K. have come down with Salmonella associated with MiceDirect shipments since 2008, as well as some 30 cases scattered across the U.S. Apparently, the U.S. Centers for Disease Control only began an inquiry this spring, and the MiceDirect facilities and product were only inspected this month. MiceDirect has announced that they are now shipping irradiated feeders to address the Salmonella; the strain involved, they say, is no hazard to reptiles.
This is not the usual way to get Salmonella from reptiles. From what I understand, people normally contract Salmonella, which is present in the lower GI tract of reptiles and birds, through fecal-oral contact. Most of us don’t go around licking reptile cloacas, but transmission can occur when, for example, handling reptile feces and not washing up properly afterwards: fingers to snake poop, then (later) fingers to mouth. The problem is exacerbated with aquatic turtles, because turtles contaminate their aquarium water: you don’t have to handle turtle feces to get contaminated, just the wet turtle. Wash your hands, people.
I have to say it was interesting to see an article about reptile keeping in the Times, particularly one illustrated with a baby red-sided garter snake eating a pinky mouse. There was this passage that I think is worth elaborating on, about thawing frozen mice: “Mr. Gilfillan and many other snake owners thaw mice to serving temperature in warm water. Dr. Barton Behravesh said people should not use a microwave oven, because the bacteria could spread to other food.” Reptile keepers tend not to use microwave ovens anyway, because frozen mice have an annoying tendency to, well, explode in them. Seriously.
