|Point Conception and Vandenberg Air Force Base hold the longest stretch of pristine coastal habitat in Central California. As the Air Force and space industries launch satellite-bearing rockets nearby, PRBO has studied seabirds at Vandenberg since 1999, including two endangered species, the California Least Tern and California Brown Pelican. This remarkable area includes a "no-take" marine reserve, providing a natural laboratory to investigate the seabirds' foraging ecology in protected and fished habitats. The diet of the Pigeon Guillemot, a featured species, varies relative to ocean conditions and habitat protection. Our studies at Vandenberg also provide a southern component for comparisons with the Farallones and other PRBO study areas to the north in the California Current System.--Bill Sydeman, Director, PRBO Marine Ecology Division|
The mission of PRBO's Vandenberg seabird program, now in its sixth year, is straightforward: learn as much as possible about the seabirds breeding at Vandenberg Air Force Base. I remember the day in April 1999 when, armed with a vague road map and a base pass granting me access, I set out to explore. At first I was overwhelmed by the area's vast expanse. Vandenberg occupies 30-plus miles of coastline with a range of habitats, from steep cliffs and jagged shores in the south to vast sandy beaches in the north, with extensive dune networks reaching inland like long fingers.
Distributed in small clumps along this coast are approximately 1,500 breeding seabirds of six species--Pigeon Guillemots, Brandt's and Pelagic Cormorants, Western Gulls, California Least Terns, and Black Oystercatchers--whose breeding dynamics we study, plus numerous California Brown Pelicans, whose roosting habits we study.
On some days, my schedule resembles that of a politician during a campaign year: 9:00 AM meeting with the oystercatchers at Rocky Point, 12:00 PM lunch with the guillemots at Point Pedernales, 2:00 PM strategize with the Least Tern management team on issues facing this endangered species. After a quick dinner and some family time, it's back into the field to meet with Julie Lanser and Elizabeth Rogan, PRBO's two other biologists at Vandenberg, and gather information on a potential colony of Ashy Storm-petrels, nocturnal seabirds. Situated just north of Point Conception, where the cold waters of the California Current meet the warm waters of the Southern California Bight,
Vandenberg is a wonderful natural laboratory--where Mother Nature hands out a new set of variables each year. This year's twist appears to be a late upwelling season that has thrown the prey base out of whack (see page 7). While Brandt's Cormorants and Pigeon Guillemots appear to be handling this well, Western Gulls and Pelagic Cormorants here are experiencing nest failures. Many of our Least Terns, having made their yearly migration from Central America, are opting not to breed altogether.
Throughout the field season, Liz, Julie and I continue our race to collect all the data we can. We know the ocean is constantly changing, and it's unknown when we'll see conditions like these again.