Diet: Butler’s garter snakes are specialists, feeding almost exclusively on earth worms. After the last ice age however, glaciers had scraped the landscape making it inhospitable for native earth worms. During this time, it’s unknown what these snakes fed on but it’s suspected they preyed largely on aquatic and terrestrial leeches. When Europeans arrived, they accidentally introduced exotic earth worms like nightcrawlers, and green worms, into the environment. While these worms are considered invasive, they created a new food source for the garter snakes. This food source, in theory, had enough of a surplus to increase the snakes’ body and clutch size as well as increase the young’s chances of survival. Unfortunately, much of their habitat has been converted into agricultural and urban areas causing the butlers garter snake to be listed as Endangered in Ontario.
Sources:
Choquette, Jonathan, and Daniel Noble. "COSEWIC Assessment and Status Report on the Butler's Gartersnake Thamnophis butleri in Canada." Species At Risk Public Registry, edited by Ronald J. Brooks, Committee on the Status of Endangered Wildlife in Canada, 2010, www.registrelep-sararegistry.gc.ca/virtual_sara/files/cosewic/sr_butlers_gartersnake_0911_eng.pdf. Accessed 26 Jan. 2022. "Earthworm Invaders." Ecosystems on the Edge, Smithsonian Environmental Research Centre, ecosystemsontheedge.org/earthworm-invaders/. Accessed 26 Jan. 2022. Marks, Steve. Personal interview. 2021. |