David called it a gopher snake, which I repeated on the Facebook page of a herpetologist friend, Harry W. Greene, an author whose wonderful memoir, Tracks and Shadows: Field Biology as Art, I had the distinct pleasure of editing (not a very common occurrence: pleasure in editing, that is). My ID puzzled Harry, who remarked: "Not impossible, but unusual for a Gopher Snake to eat a lizard . . . was it a young snake?"
This got me wondering, so I googled "snakes of Henry Coe" and got a marvelous resource in return: Amphibians and Reptiles of Henry W. Coe State Park. There I determined that what I had seen was in fact not a gopher snake (Pituophis catenifer), which has patterned skin—much like a rattler—and dines mainly on small mammals (hence its common name), but a western yellow-bellied racer (Coluber constrictor mormon). Here's its entry:
DescriptionI shared my conclusion of a racer snake with Harry, who responded, "Sounds much more likely . . . any stripes or spots visible?" (perhaps still trying to age the animal). I told him no, it was just olive brown. That nailed it, and he confirmed my guess.
Racers are slender, medium-sized snakes reaching 2 to 5 feet in length. Adults are solid colored, in shades of olive, beige, or brown. Juveniles, on the other hand, are blotched, and resemble small, wide-eyed gopher snakes. The mature racer has very smooth shiny scales with a divided anal plate. The head is narrow but still wider than the neck with very distinct brow ridges. The belly is white, light tan, or yellow in color. The male can be distinguished from the female in that the tail is longer with a wide base, sometimes even a bulge.
Racers are one of the few snakes found from coast to coast, and the 11 subspecies exhibit much regional variation. Racers favor open habitats such as grasslands and oak savannah, where they are highly active, spending much of their time foraging, often with their head raised. They are among the fastest of snakes. They are strictly diurnal and inactive at night, for their retinas contain only cones. They are dietary generalists, taking a wide variety of prey items. In spite of their scientific name, they do not kill prey by constriction but subdue it and swallow it immediately. If cornered they are aggressive and will not hesitate to strike repeatedly.
Racers are common in Coe and frequently seen on warm spring days in the open areas of the park.
That's another reason I enjoy Facebook (when I'm not busy hating it, which is sort of the case at the moment: so much discouraging news there lately . . .): I've got some super-intelligent, super-knowledgeable, and very generous friends on FB. That's something to cherish, for sure.