If you’ve spent any time at Cesar Chavez Park on the Berkeley waterfront this winter, you may have had an odd encounter: a meeting with a small brown owl, perched on a coyote bush or popping out of the riprap at the water’s edge.
That would have been a western burrowing owl, one of the few owls that hunts by day, and the protagonist in yet another battle in the endangered-species wars.
Biologist Steve Granholm, who monitors shoreline bird populations, tells me that a couple of the birds are spending the season along the park’s northern edge, and that others have been seen south of University Avenue and near Golden Gate Fields.
You may have noticed the owl bobbing and bowing at you. That wasn’t a greeting—it was a sign of agitation—but it’s why the species has been nicknamed the “howdy owl.” It’s ironic, since, as ornithologist Paul Johnsgard has written, “in most western states the familiar ‘howdy owl’ is saying a long, sad farewell.”
What the burrowing owl lacks in stature—I believe it was Carl Hiassen who described it as about the size of a beer can—it more than makes up in personality. It has fierce yellow eyes and white eyebrow and throat markings that set off its brown plumage. Male owls flare their eyebrow and throat feathers and stretch to their maximum height while cooing to prospective mates. They may also perform a circular courtship flight.
Our local owls are only winter visitors, probably from east of the hills, although they do nest elsewhere in the East Bay. They’re unique among their family in using holes in the ground as nest sites. “Burrowing” is a stretch, though. The disjunct population of burrowing owls in Florida, where the soil can be loose and sandy, do tend to excavate their own homes. But their western cousins usually appropriate a burrow from a ground squirrel, prairie dog, or other mammal. The owls’ association with burrowing rodents is what led the Zuni Indians to call them the Priests of the Prairie Dogs.
In our area, the original architect of a burrowing owl’s nest will most likely be a California ground squirrel. Lise Thomsen, who studied the owls at the Oakland Airport more than 30 years ago, found that owls had no trouble evicting squirrels from a desirable property. She also reported that although the birds’ diet included mice and young jackrabbits, they didn’t prey on the squirrels, even vulnerable youngsters. Insects, notably Jerusalem crickets, and small birds were on the menu as well.
Burrowing owls also diverge from normal owl behavior in furnishing their nests. Thomsen’s owls used divots from the adjacent golf course, along with gum wrappers and other bits of litter. They’ll also bring home cow chips and dog feces, apparently to mask the smell of their nestlings from predators. Owls, perhaps fortunately, do not have a keen sense of smell.
The owlets have a second line of defense: a distress call that bears an uncanny acoustic resemblence to a rattlesnake’s rattle. (In South America, where burrowing owls did not co-evolve with rattlers, the call hasn’t been documented). It’s accurate enough to have fooled ground squirrels, who need to have a good ear for snake sounds, and it may deter badgers and other predators. Unfortunately, it has no effect on earth-moving equipment.
Western burrowing owls have been hard hit by the conversion of grasslands to farm fields and the extermination of the rodents that provide their housing. They’re losing ground in most of the western states, including California where they’ve been extirpated from 22 percent of their former range and are declining in another 50 percent. There have been sharp decreases in the Bay Area, much of the Central Valley, and the Southern California coast. Most of the remaining population is on private land, almost three-quarters of them on farmland in the Imperial Valley, where they’re at risk from agricultural chemicals and urban sprawl.
The South Bay may still have about a hundred pairs. But owls don’t carry much weight in Silicon Valley. In one of those gestures corporate PR types like to brag about, burrowing owls have sometimes been relocated from properties slated for development. This may be good for the company’s image but seems to be of little benefit to the birds; one study found only one relocation in eight led to successful nesting at the new site. The owls often try to return to their now-uninhabitable homes.
Since state status as a Species of Special Concern and inclusion in local Habitat Conservation Plans hadn’t stemmed the decline, environmental groups petitioned last April to have the western burrowing owl listed as endangered. It turned into a classic faceoff: in the owl’s corner, the Center for Biological Diversity, Defenders of Wildlife, and the Santa Clara Valley and San Bernardino Valley Audubon Societies; in the other, agribusiness and builders’ associations.
The Farm Bureau alleged its constituents were already protecting the owls and legal requirements would be counterproductive. Madera County rancher Clay Daulton said that with “en-croaching regulations…maybe my last resort is to pave [my land] over and make some money and retire.” The state’s scientists claimed there was no good evidence that the owl was approaching extinction—although 71 percent of California’s burrowing owl population is confined to less than three percent of the state’s area, there’s really nothing to worry about.
When push came to shove, the California Fish and Game Commission voted to deny the listing petition. “Sometimes populations relocate”, said Commissioner Bob Hattoy, a former Sierra Club executive. “We all have.” The owl’s fate is expected to wind up in court.
Relocation is easier for politicians than for owls. But the birds have been flexible enough to use farmland and parks, and a few seem willing to entertain other alternatives. The burrowing owl that turned up a couple of years ago in the Embarcadero BART station may have thought it had discovered the Ultimate Burrow.