Predatory Attack by a Western Terrestrial Garter Snake on a Nestling Dark-Eyed Junco

Abstract

I observed a Western Terrestrial Garter Snake (Thamnophis elegans) attacking a large (approximately 9-d-old) nestling Dark-eyed Junco (Junco hyemalis) on 7 July 2018 near Rattlesnake Creek, Missoula County, Montana. The snake held the stillliving nestling by its head (the head was mostly enveloped by the snake's jaws) and continued to do so for 3 min before it released the now-dead nestling when disturbed by my presence. The dead nestling exhibited skin wounds on the neck but no other superficial injury. Predation on birds by Western Terrestrial Garter Snakes is infrequently reported, and I found only 2 other reports of predation on juncos by this snake species.