‘Subirdia’: Surprisingly, birds thrive in suburban areas
Ornithologist and UW professor John Marzluff writes in his new book, “Welcome to Subirdia,” that the suburbs around Seattle provide habitat for a greater diversity of bird species than either the city or nearby forests. And after 12 years of study, he has some theories as to why.
Seattle Times books editor
The author of “Welcome to Subirdia” will appear at 7 p.m. Wed., Oct. 29, at Third Place Books in Lake Forest Park, 17171 N.E. Bothell Way; free (206-366-3333 or thirdplacebooks.com).
John Marzluff bought two acres in suburbia 17 years ago. Marzluff and his wife, Colleen, are world-renowned wildlife researchers, and they purchased the forested tract in Snohomish County as a home for their nine sled dogs, their partners in previous research on raven behavior in the brutal Maine winter.
The dogs have passed to their reward, but Marzluff has turned his piece of suburbia into Subirdia, using knowledge gleaned from a life’s work with birds to turn his land into a haven.
The Marzluffs allow dead trees to stand — they’re visited by pileated woodpeckers, who dine on the termites within. (On one recent August day, Marzluff saw three of these majestic black, red and white birds.) Salmonberry hedges shelter Pacific wrens. Though the hum of the highway a block away is audible through the trees, the brush piles and feeders the Marzluffs have installed have attracted 60 bird species in all, including western tanagers, Pacific wrens, sparrows, towhees, juncos, Anna’s hummingbirds and owls, plus native red squirrels, Townsend’s chipmunks, tree frogs and coyotes.
Marzluff’s academic work and his lifelong passion for birds have merged in his beautiful and informative new book, “Welcome to Subirdia: Sharing Our Neighborhoods with Wrens, Robins, Woodpeckers, and Other Wildlife”(Yale University Press, 303 pp., $30). His conclusions offer hope in an era of despair at what humans’ destructive habits are doing to wildlife: Given a little help from human hands, birds can thrive in the midst of development.
An ornithologist, University of Washington professor and author of several previous books, including two on crows and ravens with local wildlife artist Tony Angell, “Welcome to Subirdia” offers a similar words-and-pictures combination — it’s beautifully illustrated with bird and wildlife art by Jack DeLap, one of Marzluff’s doctoral students at the UW.
The book’s conclusions represent decades of study by Marzluff and other researchers in areas as close as Seattle and as far afield as London, Berlin, St. Andrews in Scotland, and Auckland, New Zealand.
In urban Seattle, Marzluff’s research crew found birds even in degraded areas like the industrial neighborhood along the Duwamish River, where they spotted Caspian terns, peregrine falcons and belted kingfishers. But the greatest bird diversity occurred not downtown, or even in forest reserves, but in outlying suburban neighborhoods — “the jumbled collection of houses, allotments and gardens, derelict and vacant land, golf courses and other recreational sites, and by the cemeteries, schoolyards, highway and railway verges, business parks and shopping centres, situated amid the greenways that comprise suburbia,” Marzluff wrote in a recent opinion piece for Aeon Magazine. These areas offer shelter and food, including both bird feeders and a rich mix of plant species that birds rely on.
Bird surveys from more than 100 locations in and around Seattle, Marzluff writes in his book, revealed that “the greatest diversity was not in the most forested setting. Instead, bird diversity rose quickly from the city center to the suburbs and then dropped again in the extensive forest that eases Seattle into the high Cascades. We had discovered subirdia.”
Marzluff’s teams conducted studies of selected areas before, during and after development; birds were displaced during development, but many species came back.
“This is not an observation that comes from a quick and dirty look,” he said in a recent interview. “This is 12 years of research. Birds can thrive in our presence.”
Not all bird species are equally resilient. Marzluff classifies birds as “adapters,” “avoiders” and “exploiters.”
Adapters learn to live side by side with humans. Scientists have even documented changes in coloration and gene makeup that they attribute to adaptation to an urban environment. Adapters include red-winged blackbirds, killdeer, American goldfinches, Bewick’s wrens, barn owls, Cooper’s hawks and white-crowned sparrows.
Avoiders, birds that need habitat that only relatively wild places can provide, don’t fare so well. They include the yellow-billed cuckoo, the marbled murrelet, the pygmy owl, Wilson’s warbler, Swainson’s thrush and the Pacific wren. The Pacific wren needs a thick native understory usually removed by development, and is often shoved out by its larger Bewick’s cousin.
Exploiters include birds who we all know well — Canada geese, European starlings, house sparrows, mallards, rock pigeons and crows. These birds thrive side by side with humans — crows “love grass and a little garbage,” Marzluff says.
Why are birds so adaptable? “Flight, for one,” Marzluff says. A bird can escape threat through flight — a salamander or toad cannot. Also, birds don’t threaten people — large mammals tend to bring out a defensive response in humans.
Marzluff is relatively optimistic about the future of birds in the Seattle area, but he does worry about the gangbuster pace of development in the city and the suburbs. Right now Seattle sustains between 40 and 60 percent of its tree cover, depending how it’s measured — if that number drops below 30 percent, the fragile balance of “subirdia” will be threatened, according to landscape-ecology theory.
For the health of this system to endure, people must pitch in. Subdivisions can be designed with less lawn and more forest. On a recent walk in his own neighborhood, Marzluff showed off a subdivision laid out with smaller lawns and tracts of forest that undulate in belts behind the houses. His neighborhood surveys have showed high bird counts in these areas; not so much in another nearby neighborhood, platted out with maximum lawn and minimum trees.
As an academic who has spent his life’s work immersed in the animal kingdom, Marzluff has harbored plenty of dark thoughts about the rate of habitat extinction worldwide. But he also knows firsthand that birds can thrive, with a little help from humans, one block at a time. “Where you live is a great place to start,” he says.
Mary Ann Gwinn: 206-464-2357 or firstname.lastname@example.org. Gwinn appears every Tuesday on TVW’s “Well Read,” discussing books with host Terry Tazioli (go to www.tvw.org/shows/well-read for archived episodes). On Twitter @gwinnma.