I’ve seen some incredible organisms over the years, but one of my favorite critters is the eastern hognose snake (Heterodon platirhinos), a stocky snake found throughout the open woods and dry fields of the eastern US.
One reason that the hognose really captures my attention is its elaborate series of anti-predator displays. First they inflate their bodies and hiss loudly. If still annoyed, they may spread the nape of their neck creating a ‘hood’, much like a cobra. At this point they might also gape their mouths widely and make lunging strikes at the attacker. If these fail to deter a bothersome predator, the hognose will expel a rather noxious musk from its cloaca, and then roll over and play dead (known as thanatosis).
Here’s a YouTube video of a hognose snake I saw at Lake Jordan, NC, performing the second half of its anti-predator repertoire. My colleague Marketa Zimova shot the video.
Individuals seem to vary somewhat in how vigorously they display any of these behaviors. Despite their initial aggressiveness, they never actually attempt to bite and are completely harmless to humans. The entire sequence is elaborate, well-orchestrated, and presumably alarming for would-be predators such as hawks.
But there is more to the hognose than just a talent for drama. Hognose snakes are ecological specialists that eat toads and have some amazing adaptations (like an upturned spade nose for digging and rear fangs) that enable them to find, unearth, and consume such toxic prey. For more information about the hognose snake in North Carolina check out http://www.herpsofnc.org.
Sean Giery is a PhD student in Applied Ecology at NCSU. He studies how human alteration of ecosystems is affecting the evolutionary ecology of wild populations. He also likes critters. For more about his research: http://seantgiery.weebly.com.
These are very convincing actors. I saw one once that tried very hard not to “die,” and after hooding out for us it went through an incredible death scene, including ralfing up a little toad it had recently eaten. The toad was still twitching! I felt sort of bad for it after that. We picked it up on a stick, and it looked very dead, except for the little tongue that kept darting out to see if we were still there. We left it alone after that. A fun snake.