Tuesday, July 6, 2010

Thamnophis sirtalis sirtalis

Yesterday morning, as I got my bike out to ride to work, I came upon this snake lounging on the stone steps coming down from our back yard. I didn’t have time to leisurely shoot this reptile because, well, I had to get to work, so the pictures aren’t amazing. But at least I documented another vertebrate. I think that’s two!

So T. sirtalis sirtalis, the Eastern Garter Snake is a subspecies of the Common Garter Snake. The term subspecies gets a little hard to define (considering species is hard to define) but it’s basically another distinction under species. There’s not a whole lot to say about them: they’re little snakes that live in most parts of the US. They are nocturnal and diurnal (not crepuscular?) and eat little amphibians, worms and slugs.

One somewhat interesting thing about these snakes is that they give live birth. This is called viviparity and when I was in grad school I found that there’s actually a whole lot of squamate reptiles (snakes and lizards) that do this. I think a lot of people assume that mammals are the only ones who give live birth but sharks and reptiles also employ this strategy. It’s evolved a good number of times over the last few hundred million years.

No comments:

Post a Comment