CA red sided garter snake (Thamnophis sirtalis infernalis) with its toxic newt (Taricha) prey. Classic example of an evolutionary arms race. The newts are toxic, the garter snakes are resistant, so the newts become more toxic, garter snakes become more resistant, etc.. (1/n)

This continues until the newts are so toxic that nothing can possibly eat them.... except the resistant garter snakes! I'd wanted to photograph this interaction for some time, and got lucky on a recent visit to Marin co., CA (2/n)

The garter snakes that eat newts do so at a cost though. Populations of tetrodotoxin resistant garter snakes are slower moving than non resistant populations. & when they do eat a newt they get intoxicated and may be lethargic for hours after (3/n)

But the garter snakes may actually retain the toxins from the newts! Some neat research found tetrodotoxin in the livers of newt feeding snakes up to 7 weeks after eating newts. Making them poisonous enough to kill some of the snake’s predators! (4/n)

The newt tetrodotoxin induced lethargy may explain why this snake stuck around for as long as it did. Just kind of yawning and attempting to clear its mouth of the thistle seeds it had gathered while eating the newt. (5/n)

Anyways please enjoy the series of photos, and if you'd like more info - I did a bit of a more in depth description of the interaction and observation on Instagram (3 separate posts, the link is to the 1st): https://www.instagram.com/p/CD1uMaIsuk1/  (6/6)