Sunday, December 2, 2007
Red Sally, the cold blooded night stalker
October 25, 7:27PM: We are back at Point Reyes National Seashore again, where a cold blooded night stalker padded past the camera looking for edible victims in the leaf litter.
This record of an Eschscholtz salamander (Ensatina eschscholtzii) was a stroke of good fortune. The camera's passive infrared (PIR) sensor does NOT respond to cold moving bodies. A warm moving body -- brush rabbit, deer mouse, or wood rat -- must have triggered the camera just before the salamander moved out of the frame. Whoever it was, I am grateful.
Ensatina, a salamander without lungs . . . I remember it well from collecting forays on the San Francisco peninsula. Its fruity (ripe persimmon) complexion, laterally compressed tail, and constricted tailbase give it away as the yellow-eyed subspecies xantoptica -- commonly called the red salamander.
Red Sally's fiery coloration reminds some predators of bad dining experiences. It is believed to trick birds by looking like a newt. It is a mimic of newts. We have three species of newts here, and all of them have skin laced with tetradotoxin, the same stuff that makes pufferfish deadly poisonous. Birds that have gagged on toxic newts are tricked by Red Sally the imitator. But the salamander probably doesn't fool snakes, that have limited color vision, but a powerful Jacobson's organ.
Red Sally chooses a subterranean existence until the fall rains. Ninety-four years ago and not far from here the California naturalist C.L. Camp found a red salamander nest 2 feet deep in a mountain beaver burrow. Why not? Coastal scrub offers little in the way of ground cover and fallen logs, but mountain beaver burrows and woodrat nests offer a stable microclimate and plenty of insects, though they don't guarantee freedom from predators.
Stebbins notes that "When the surface is damp and temperatures not too high, considerable time is spent above ground where most feeding probably occurs." That's probably what Red Sally was doing here.
Stebbins, R.C. 1951. Amphibians of Western North America. Berkeley and Los Angeles.