Shorthead garter snake
| Shorthead garter snake | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Subphylum: | Vertebrata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Colubridae |
| Subfamily: | Natricinae |
| Genus: | Thamnophis |
| Species: | T. brachystoma |
| Binomial name | |
| Thamnophis brachystoma (Cope, 1892) | |
Thamnophis brachystoma, the shorthead garter snake or short-headed gartersnake, is a small species of colubrid snake found in small pockets in northwestern Pennsylvania and southwest New York. Name comes from the Greek words "Brachy", meaning short, and "stoma", meaning mouth.[1]
Description
A small species of snake that averages 254-559mm.[1] There is no apparent distinction between the body and head.[1] Unlike Thamnophis sirtalis, there are no black spots between stripes in T. brachystoma.[1] Dorsal coloration tends to be olive or olive-green with three (1 dorsal, 2 lateral) beige to yellow stripes running the length of the body.[2] There is a distinct sexual dimorphism in this species with females being larger than males.[2]
Habitat
This garter snake is commonly found in old fields and meadows, but can occasionally be found in wooded areas. They are almost always found within several hundred meters of a field. It is believed that on sunny days they will be openly basking, however, when a population study was conducted they were almost invariably found under cover objects such as wood and rocks. Individuals were only encountered in the open on cloudy days.[2]
Behavior
This species is slow to bite would be handlers, but will readily expel musk and feces.[2] Shorthead garter snakes can commonly be found near one another under cover objects, with no apparent correlation to seasonality or breeding cycles.[2]
Diet
This species feeds exclusively on earthworms and will, even in captivity, refuse all other common food items such as salamanders, frogs, and fish.[2]
Reproduction
Reproduction occurs in spring shortly after emerging from the hibernacula. Females generally emerge with ovarian follicles already well developed. Females in New York breed every other year while females in Pennsylvania breed annually. Males use stored sperm for breeding. The testes are small after emergence, reaching full size by midsummer. After this point, sperm will be stored for later use in the spring.[2] T.brachystoma is believed to be viviparous, with experiments showing a transfer of amino acids between mother and offspring.[3]
References
- 1 2 3 4 Bothner, Richard C. "Thamnophis brachystoma." Catalogue of American Amphibians and Reptiles 190 (1976): 1-2.
- 1 2 3 4 5 6 7 Hulse, Arthur C. Amphibians and Reptils of Pennsylvania and the Northeast. Ithaca, New York: Comstock Pub. Associates, Cornell University Press, 2001. Print.
- ↑ Van Dyke, James U., and Steven J. Beaupre. "Stable isotope tracer reveals that viviparous snakes transport amino acids to offspring during gestation." Journal of Experimental Biology 215.5 (2012): 760-765.