Kevin Wells of Eugene took this photo of a garter snake while on a hike with his girlfriend in April 2010 at Fern Ridge Reservoir.
“A little ways in, this relatively large and particularly colorful species of garter snake came slithering across the path, and as a snake lover I couldn’t help but snap a few pictures,” Wells said. “He was displaying his defensive technique of flattening the head to make it look bigger, and getting in the strike pose, but I didn’t get close enough for him to strike. Beautiful animal.”
You won’t see this garter snake face outside the Willamette Valley. Its flattened head is an attempt to look scary, probably as a direct response to the photographer’s presence. This species, the common garter snake, ranges widely across the continent and consists of 13 subspecies of various color patterns. The subspecies endemic to the Willamette Valley is called the red-spotted garter snake (Thamnophis sirtalis concinnus). The orange head is unique. On the body, there’s a yellow stripe on top, red-orange spots on the sides and all against a black background. Some individuals have a copper-colored head.
There are two other species of garter snakes in the Willamette Valley, the Northwestern and Western Terrestrial garter snakes and they do not have the bold coloring of the red-spotted garter.
Common garter snakes hunt for frogs, salamanders and tadpoles. They’ll also eat earthworms, slugs, leeches or other prey of an appropriate size but rarely insects. They’re capable of eating rough-skinned newts, although a newt has enough tetrodotoxin in its skin to kill a man or any other animal. They are resistant but not immune to the toxin. After eating a newt, a garter snake may be lethargic for a few days.
Research indicates that snakes previously regarded as non-venomous, produce venom to some extent. That includes garter snakes. They don’t possess fangs or the ability to inject venom. The toxicity is diluted in their saliva and only capable of affecting their small prey. For people, the affects of this venom is negligible or, at worst, a source of minor irritation.
They don’t always bite, even if you handle them. Be gentle if you try to pick one up because it’s easy to injure them. You should also be aware of the foul-smelling fluid secreted from their postanal glands (near the back end) that’s difficult to wash off. Yuck!
Garter snakes are live bearers and give birth to more than a dozen young in late spring or summer. In winter they hibernate collectively, sometimes by the hundreds, in deep crevices or burrows. The largest individuals, reaching four feet, are usually females.
Information provided by Don Boucher of the Neighborhood Naturalist, www.neighborhood-naturalist.com