VALUE OF OAKS TO WILDLIFE IN THE URBAN FOREST OF SACRAMENTO, CALIFORNIA
Daniel A. Airola; Conservation Research and Planning; 114 Merritt Way, Sacramento, CA, 95864; (916) 494-1283; d.airola@sbcgloblal.net; Steven E. Greco
Urban development occupies >375,000 ha (6%) of California's Central Valley, and expansion continues to displace natural and agricultural landscapes. The value of urban areas as habitat for native wildlife, and the characteristics that determine their values, however, remain little-studied. I present three studies of bird use of native oaks in urban Sacramento. One study showed a strong association between the abundances of oak canopy and 20 insectivorous neotropical migrant songbirds. Another study showed that in the non-breeding season, 13 species occur or are substantially more abundant in urban forest only when native oaks are present. Another study showed that urban California Scrub-Jays (Aphelocoma californica) traveled up to 660 m to harvest and cache acorns and dispersed thousands of acorns from groups of bearing oaks. Most oak seedlings in urban gardens are removed as weeds, but jays establish many oaks urban lands that are less intensively managed, contributing to habitat for other species. Study results demonstrate previously undocumented importance of oaks to urban wildlife and suggest that protecting oaks and increasing their planting in urbanizing areas of the Central Valley could provide substantial future habitat benefits for native birds.
The Anthropocene: Decline & Extinction I