This time of year, it is not uncommon for hikers to encounter three of our most common and charismatic local snakes — the garter snake, the gopher snake and, of course, the northern pacific rattlesnake. Like us, these snakes avoid the hottest days of summer and seem to enjoy this magical time when summer slides into fall. Because trails and roads in our open space areas are now rimmed with dry grass and other senescent vegetation, snakes are even easier to spot than during the more verdant days of spring and early summer.
Snakes are among that class of creatures (along with spiders, bats, and sharks) that provoke fear and loathing among a good portion of the human population. From Adam and Eve to Harry Potter, snakes have been dreaded and demonized, portrayed as treacherous and even vindictive. While it is certainly true that some venomous snakes can deliver a nasty and potentially fatal bite, lumping all snakes into the category of killer blinds us to their many mind-blowing talents and the beneficial role they play in our local ecosystem.
Snakes evolved from lizards some 200 million years ago. Although there are some legless lizards today, there are no legged snakes! Some more primitive snakes — like pythons and boas — still have vestigial hind legs. Romantically referred to as “anal spurs,” these tiny clawed limbs are used by some species to hold onto their chosen one during mating. All snakes lack eyelids and therefore never blink. Rather, their eyes are covered by a transparent membrane called a brille. When snakes shed their skin, the brille is shed with it. As any pet snake owner will tell you, the brille becomes cloudy just before molting, giving us a clue about what is about to happen. Unlike lizards, who tend to shed their skin in patches, snakes gracefully leave behind a mostly intact tubular marvel, often at the entrance to their burrow.
Of the 33 native snake species in California, at least a third occur in Sonoma County. Some we rarely see either because they are nocturnal, or very small, or spend most of their time hanging out underground. Garter snakes, gopher snakes and rattlesnakes, however, are encountered relatively frequently, although identifying them can be difficult because of the great variation in their coloring and the fact that they have tendency to mimic one another.
The garter snake
The garter snake (genus: Thamnophis) is the most common snake in North America. Often erroneously dubbed the “garden snake,” this ubiquitous serpent is named for its resemblance to the striped garters once worn by men to hold up their stockings or sleeves. The garter snake is the only type of snake on the continent that lives as far north as Alaska. Relatively well-adapted to cool climates, most garter snakes are excellent swimmers and hibernate in large dens, which makes them susceptible to collection for the pet trade. Garter snakes are not dangerous to humans, as long as you don’t mind being smeared with foul-smelling slime. When threatened, garter snakes release a stinky bad-tasting musk and spread it across their skin by writhing. This strategy, designed to make themselves distasteful to predators such fox and coyote, causes curious humans to go running for hand sanitizer. Like the northern pacific rattlesnake, garter snake young are born not in eggs but directly from the mother’s body, a type of live birth known as ovoviviparous (the young are nourished in an egg sac retained in the mother’s body). In cooler climates, the longer mom keeps those eggs inside her body, the more likely her young are to fully develop.