The good, the bad, and the messy

The poultrygeist of People's Park and other fluffy-bird stories

First it was the Canada geese. After some anserine genius figured out that they didn't really have to migrate, they began their takeover of urban parks, golf courses, and other handy pieces of greensward. (Geese love golf courses. I saw my one and only endangered nene at the Big Island Country Club outside Kona, on the 12th hole.) These are untidy birds, and it's not just a matter of a little goose poop. The 2,000 Canadas at Oakland's Lake Merritt generate an estimated ton of droppings every day.

And now another large bird is making its presence felt in the East Bay: the wild turkey. For a couple of years now I've been seeing reports of turkeys in the Berkeley Hills. Last fall they showed up on the UC campus, and a lone bird, whose ultimate fate is unrecorded, hung out at People's Park during the week before Thanksgiving. Turkeys can be cantankerous birds, and there have been some awkward encounters.

The Berkeley turkeys, and most other California populations, appear to be descendants of Texas birds of the Rio Grande subspecies, introduced to the state by the Department of Fish and Game for sporting purposes. Today there are around 100,000 of them statewide, in every county but San Francisco.

How you feel about the turkeys seems to depend on how alien you think they are. Don Roberson, author of Birds of Monterey County, points out that wild turkeys - possibly the same as the living species - flourished in Southern California during the Pleistocene, and there's one enigmatic fossil from Northern California, a thighbone from Potter Creek Cave in Shasta County. Roberson contends that "the new, introduced population might be thought of as a `reintroduction' of a native species," with "little or no deleterious effect on other native species."

Is that assumption justified, though? I ran the question by Alan Krakauer, who, as a graduate student at UC Berkeley, helped clarify the wild turkey's mating system. (Bands of brothers display to females as a group, but only the dominant sibling gets to mate.) Krakauer said the answer was anyone's guess at this point, with no published studies yet. He doubts that turkeys compete with native birds such as California quail for nest sites, or exclude other bird species from their nest area. Any impact would come from direct predation on small invertebrates - snakes, frogs, salamanders - or competition with other species for acorn mast and other resources.

Krakauer referred me to UC's Reginald Barrett, who has been studying turkey ecology at Annadel State Park in Sonoma County. The Annadel turkeys, according to Barrett, feed mostly on exotic plants, with a few insects and salamanders on the side. "It would be expected that any non-native species would have some effects on native ecosystems," he says. "It will require considerable more study to document this, however."

So I'd say the jury is still out on the ecological consequences of the turkey boom. And it's not as if the California birds have escaped their natural enemies. Humans aren't the only ones with a taste for turkey. Mid-size mammals (raccoons, opossums, skunks, even rodents) and snakes prey on eggs and chicks; adults and poults (adolescent turkeys) are vulnerable to mountain lions, bobcats, coyotes, golden eagles, and great horned owls. It looks as if there's a spot in the local food chain for the newcomers.

Joe Eaton