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introduction—

the serpentine gate

Like other large bodies of water, San Francisco Bay takes on every color at some time, from black at midnight to white at noon. To me, the most characteristic one is a milky bluish green that I see on summer evenings when I cross the Richmond Bridge going east. There is a sense of celestial depth about it, paradoxical as that might be. It seems very alive after the baked brown of the inland hills.

It is the color of serpentine, which is appropriate. Serpentine is a common rock around the Bay Area, but a strange one. It comes from earth’s mantle, a hot layer of heavy metals many miles beneath the surface, and it reaches the sunlight only after millions of years of geological processes that would be cataclysmic if they weren’t so slow.

Huge plates that form the planet’s crust collide and slide against each other, dragging slabs of the underlying mantle along. When one plate rides over another in the tectonic process called subduction, mantle material scrapes onto earth’s surface, forming an igneous rock called peridotite, which weathers to red or black. But some mantle material mixes with water during subduction, forming a metamorphic rock that weathers a slick, milky bluish green at the surface. It is called serpentine because its color and texture seem snakelike.

Some serpentine further metamorphoses into jade, a semiprecious stone thought to have magical properties. Serpentine has its own magical property. Because of its heavy metal chemistry, its soil resists the weedy exotic vegetation that has preempted much of the Bay Area, allowing many beautiful native plants and the animals that depend on them to survive. For plants that have been evolving here for millions of years to persist on rock that has been forming for an estimated 200 million years seems to embody the evolutionary nature of this place. And for that rock to be associated with the serpent, the creature that—more than most—connects with the depths of earth and time, seems to embody the Bay Area’s mythic nature. It’s easy to imagine some sinuous ridgetop of slick blue-green rock as a coil of a snake, so big and old that its movements are too slow for human perception—a World Serpent.

The Golden Gate is a misnomer in geological terms. The only natural gold I know of in the Bay Area is the residue of Mother Lode mining scraps that rivers have washed into the Bay. It’s really the Serpentine Gate.

Of course, the Chamber of Commerce wouldn’t like calling it that. Prejudice against serpents and anything associated them has been endemic to Western civilization since Genesis. Prejudice persists even in these “green” times. The illustrator of my book The Klamath Knot made a wonderful jacket design of a World Serpent coiled around the Klamath Mountains. But market research at Sierra Club Books rejected it for a less inspiring one of an anthropomorphic myth, the giant Bigfoot.

The prejudice is recent. Most cultures, including Western ones, have revered snakes because of their associations with depths and origins. The ancient Greek oracles and Eleusinian mysteries centered on snakes. The greatest prophetess, the Delphic oracle, was the Pythoness. Many learned volumes have been written about snake mythology. But the most interesting way into snake lore is through the snakes themselves, preferably the local ones.

The Bay Area isn’t the snake capital of the world. It doesn’t, for one thing, have green snakes, the color that people archetypically associate with them. (Children usually color snakes green.) The local rattlesnake’s scientific name used to be Crotalus viridis, the green rattler, and although there are greenish rattlers in the West, Bay Area ones I’ve seen are brownish or reddish. The only remotely green snake here is the racer, which can be olive drab when it’s not plain brown.

Archetypes aren’t everything, however, and the Bay Area may be the snake capital of the West Coast. Species from all over converge on our convenient location and salubrious climate, about equally divided among ones with northern, eastern, and southern affinities. Roughly two dozen species live here, although it’s hard to be sure because snakes are such cryptic, supple creatures. Legless crawlers may seem primitive, but fossils show that snakes are the most recently evolved of major vertebrate groups, appearing about 100 million years ago, after mammals and birds. Evolution often diversifies by simplifying: snakes have traded legs for a versatile niche in the interstices of things. And they can be hard to find there. In five decades of hiking around the Bay Area, I haven’t seen all the species thought to live here.

Only one species is really commonplace, like deer or quail. That is the gopher snake, the medium-sized tan-and-brown-mottled species that stretches lazily across paths even in the Berkeley Hills. It is an easygoing snake when mature, although little ones can be bratty, striking and vibrating their tails at passersby. I suppose one reason gopher snakes are so common and good-natured is that they are well fed: they eat an abundant variety of small mammals, including gophers.

Garter snakes are North America’s most common snakes, but there are so many species that it’s hard to know which you’re seeing. The Bay Area has three, but there are several subspecies and an impossible tangle of common names. Most garter snakes have yellow stripes, but two species here also have other colors. One of these, Thamnophis sirtalis, has red stripes or blotches—and often a blue belly. It is common in terrestrial habitats, although a subspecies, the San Francisco garter snake, is endangered. Another common species, T. elegans, has red stripes or blotches—rarely a blue belly—and lives in similar places. The other Bay Area species, T. atratus, has only yellow stripes and is common in aquatic habitats. The two terrestrial species may frequent water too, however. Garter snake identification is just a mess, although stripe color sometimes helps. Happening once on a garter snake eating tadpoles of the endangered red-legged frog, I knew it wasn’t one endangered species eating another because it had only yellow stripes.

Bay Area garter snakes, at least some of them, have one uncommon talent. Snakes are of course notorious for injecting poison with hypodermic fangs, although most don’t have poison or hypodermic fangs. But garter snakes here are famous for their ability to digest the virulently poisonous bodies of two local salamander species, the California and rough-skinned newts, which can contain enough toxins in their skins to kill multiple humans. Bay Area newts are the most poisonous on the West Coast, and they may have become so in an “arms race” with Bay Area garter snakes.

The Pacific rattlesnake is the only other species I’ve seen here very often. In protected areas like Mount Diablo, rattlesnakes can be almost as visible as gopher snakes, and they have similar lazy dispositions in my experience, although I’ve never deliberately gotten close enough to test this. (Rattlesnake venom seldom kills humans, but an envenomed bite is very painful and may cause lasting damage to tissue.) I’ve accidentally walked within a foot or two of some and gotten no response. I’ve never even provoked a rattle here. The snakes just crawl away. I’ve used a pole to coax rattlers off roads a few times, and they don’t coil or strike, just feint irritably at the pole before departing.

Perhaps Bay Area rattlesnakes are phlegmatic because, like gopher snakes, they have plentiful food sources, especially California ground squirrels. Rattlesnakes live on such close terms with the squirrels—in their tunnels—that adults may be immune to rattlesnake venom, having survived a bite or two. Rattlers mainly eat young squirrels, although adults defend their babies by kicking sand or waving their tails at them. Females rub shed snake’s skins on themselves and their babies, thus confusing the rattlers’ sensory organs.

Maybe some rattlesnakes here have just given up bothering about people because there are so many of us wandering around. Once, unwisely climbing a steep grassy slope off-trail, I came face to face with a rattler in a squirrel hole under a rock overhang, and it didn’t blink (figuratively speaking, that is—snakes don’t have eyelids). It didn’t even flick out its tongue, the serpentine version of curiosity. If a snake could have an expression, I would say it looked resigned.

The only rattlesnake bite recipient of my acquaintance was a scientist with a captive specimen. Still, it’s hard to convince people that rattlers are statistically far below bathtubs on the danger scale. Their Genesis voltage remains high enough to boil the brains of a cool customer like Joan Didion as she muses on her Sacramento Valley family cemetery in Where I Was From:

When I was in high school and college and later I would sometimes drive out there, park the car and sit on the fender and read, but after the day I noticed, as I was turning off the ignition, a rattlesnake slide from a broken stone into the dry grass. I never again got out of the car. . . .

I had seen the rattlesnake but I had failed to get out of the car and kill it, thereby violating, in full awareness that I was so doing, what my grandfather had told me was “the code of the West.”

The most disturbing snake experience I’ve had in the Bay Area wasn’t with a rattlesnake but with a common king snake, which, because it preys higher on the food chain than gopher snakes and rattlesnakes (in fact, on gopher snakes and rattlesnakes), is less numerous. I was at a stable getting manure for a garden when the bottom of the hole I was digging suddenly turned into a big black-and-white-banded snake. It didn’t do anything except crawl deeper into the dung heap, but the surprise was dizzying. There’s something powerfully chthonic about a black-and-white-banded snake, and I’ve always felt a frisson about seeing king snakes emerge from the ground, which is how I’ve usually—albeit infrequently—seen them.

Ted Hughes, English poet laureate from 1984 to 1998, evokes this in a poem about a 1959 trip across America:

WE CAME TO A STONE

Beside a lake flung open before dawn

By the laugh of a loon. The signs good.

I turned the stone over. The timeless one,

Head perfect, eyes waiting—there he lay

Banded black,

White, black, white, coiled. I said

“Just like the coils on the great New Grange lintel.”

One thing to find a guide.

Another to follow him . . .

—“The Badlands”

King snakes’ rattler diet certainly gives them cachet. And they are beautiful snakes. I think the other king snake species that occurs in the Bay Area, the mountain king snake, is the most beautiful snake in the West. It is banded black, white, black, red, black, white—as Ted Hughes might have described it. But I haven’t seen it here.

I’ve seen ring-necked snakes here about as often as common king snakes, although that’s not necessarily proof of rarity. One study estimated a population of nine hundred ring-necked snakes in an area the size of a football field. They are pretty little snakes, maximum length about three feet, with orange or yellow neck rings and bluish bodies. A smaller local snake may be even more numerous, although it’s hard to tell because it’s even less visible. The sharp-tailed snake is the smallest I’ve seen here, eighteen inches maximum, and it spends most of its sedentary life underground, emerging at night to eat slugs.

The strangest snake I’ve encountered in the Bay Area is the rubber boa, which, as its name implies, belongs to the group that includes pythons, anacondas, and boa constrictors, the ultimate World Serpents. Rubber boas are even more archetypical than giant pythons because they are a relict of the late dinosaur age—long before gopher snakes and rattlesnakes. They are as efficient at constricting their prey as their big relatives: Harry Greene, a snake expert formerly at UC–Berkeley, recorded one individual that had just eaten three moles. Their maximum length is thirty inches, however, so they tend to be overlooked. I thought a foot-long one that I encountered on the Coast Trail at Point Reyes National Seashore was a piece of brown-and-yellow bungee cord until I picked it up. Then it coiled and gripped my finger with a pair of little legs on its rear end. Boas show their evolutionary age by being the only snakes with such vestigial legs, which they use not to get around but to grip sexual partners.

I once dreamt of digging up a rubber boa so big that it curled all the way around a backyard garden. At least, its head was at one end and its tail at the other: I couldn’t see how much more of it there was, and I couldn’t decide whether to dig up more of it or to start burying it again. There was a sense of danger in this, but also of exhilaration and, somehow, reassurance. This had to do with a series of brilliantly marked birds that landed on a bare sapling in mid-garden and then zoomed away again—a crimson-black-and-white sapsucker, a scarlet-yellow-and-black western tanager, and a black-and-white poorwill. Since poorwills are actually grayish-brown, nocturnal birds that perch on the ground, the latter seemed particularly significant for some reason.

There is a group that I’m not sure about because they are so fast. I may have seen a racer or a striped racer, but all I could see was sinuous bodies slipping through chaparral or grass. I could be pretty sure it wasn’t an Alameda striped racer, a subspecies of the latter, since it is endangered. I did have an impressive sighting of another possible Bay Area member of this group—a big purplish snake called the coachwhip—but not here. It appeared so suddenly before my car at a freeway overpass south of Joshua Tree National Park that there seemed no way not to hit it, but when I stopped and looked, it had disappeared. Harry Greene observed that coachwhips “almost defy the laws of physics at times.”

The snakes I’m sure I haven’t seen are those specializing in the dry habitats of the eastern Bay Area. That is the remotest and most trashed part, between agribusiness, wind and solar farms, and hazardous research or industrial facilities. The best-known arid reptile habitat, Corral Hollow, is the site of a state vehicular recreation area, and then there was the Altamont Speedway from 1966 until it closed in 2008. Having endured the 1968 Rolling Stones concert there, I can testify to its ecological grimness. Even in protected areas like Round Valley Regional Preserve near Brentwood—actually one of the most beautiful landscapes here—local snakes are elusive because arid land species largely live to beat the heat, emerging at night.

There are four such species known here. The California night snake, the size of a garter snake, is the Bay Area’s other poisonous snake, subduing its frog or lizard prey with venom from enlarged teeth on the back of its upper jaw. It’s not dangerous to humans, so it doesn’t have a rattlesnake’s charisma. The California black-headed snake is smaller than the sharp-tailed snake and stays underground more. The glossy snake is a smaller, paler relative of the gopher snake. The long-nosed snake is a drabber relative of the mountain king snake.

If this was PBS Nature, I’d proceed to lecture about how all snakes are threatened everywhere. And it’s true enough in the megalopolis. Even in parks, mountain bicyclists who insist on illegally riding foot and horse trails kill snakes—I’ve found the bodies. Some people deliberately kill snakes just because they don’t like them, which humans probably always have done, reverence or not. Apollo, god of arts and sciences, slew the primordial Great Python, although the corpse just came apart and crawled away to become the local ones of rites and oracles.

. . . a gigantic serpent.

Python by name, whom the new people dreaded,

A huge bulk on the mountain side. Apollo,

God of the glittering bow, took a long time

To bring him down . . .

In memory of this, the sacred games

Called Pythian, were established . . .

—Ovid, Metamorphoses

There are interesting questions as to why snakes are threatened. Much native wildlife has adapted to urban living—mostly birds and mammals but some “herptiles” too. Salamanders abound in gardens; frogs and turtles survive around creeks and ponds; I’ve seen a native fence lizard in my North Berkeley neighborhood. But I’ve never seen a snake—not even the most common or most secretive kind. (Given their slug diet, little sharp-tailed snakes should be welcome garden residents and may persist in some suburban backyards, but not mine.) Cats, rats, and cars must have a lot to do with this. Sun-warmed roads are narcotic for night-roaming snakes. Still, it’s puzzling that a group that succeeds in so many other hostile environments should fail in this one.

Maybe they just need time to adapt. Snakes are slow, comparatively speaking, but so is evolution. Another interesting aspect of Bay Area snakes is that competitive exotic species and diseases don’t seem to have impacted them. Introduced mammals, birds, plants, turtles, and frogs have run riot, but I know of nothing here like the situation with escaped Burmese pythons in Florida, although pet owners must release or lose many exotic snakes here every year. I’ve never seen a feral exotic snake here, anyway. Maybe, where they do survive, native snakes have filled the ecological niches so efficiently that intruders can’t get in.

Civilization certainly has changed the Bay Area in the past two centuries with its wonders like the Golden Gate Bridge. Some say that it has “transformed” the place and proclaim an “end of nature.” That is nonsense. According to probability math, what has lasted longest will last longest. So it’s 100 million years of snakes against five thousand years of bridges. And of course the World Serpent of our blue-green ridges is not always imperceptibly slow in its movements.

Vita longia, ars brevis.