Project Start Date: 1999

Background:
Vandenberg Air Force Base (VAFB) is located on the California coast, just north of Point Conception. This location, being close to the boundary where the cold waters of the California Current meet the warmer waters of the Southern California Bight, provides a unique opportunity to study seabird population biology in a dynamic system. In addition to being the southern mainland breeding limit for many seabird species, the California coastline north of Point Conception experiences exceptionally strong, seasonal wind-generated upwelling events. Thus, there is much interannual fluctuation in biological productivity and food web structure in this area. As top predators of marine ecosystems, seabirds are greatly influenced by these interannual fluctuations.

Although there is not a large human presence along the coastal margin of VAFB, there are human activities that could potentially have major impacts on seabird populations. These include rocket launches and oil spills from offshore oil drilling. Sonic disturbances during rocket launches can potentially cause nest abandonment, especially if they occur during key periods of the breeding season. Oil spills are notorious for their detrimental effects on seabird populations.

PRBO initiated its Vandenberg Seabird Program in 1999 with the help of Nancy Francine (biologist at VAFB). Initial studies focused on non-endangered seabirds breeding at VAFB. In 2001, we added two endangered species (California Least Tern and California Brown Pelican) to our studies. VAFB has the second largest Least Tern breeding colony north of Point Conception. Although Brown Pelicans do not breed at VAFB, the coastline contains a diverse array of roosting habitat used by non-breeding pelicans, including 4 sites identified as important pelican roosts in California.

Objectives:
1) To study the population dynamics, breeding biology, and foraging ecology of all seabirds breeding along the coastal margin in relation to oceanographic conditions.
2) To manage, protect, and aid in the recovery of California Least Terns.
3) To gather year around information about Brown Pelican activity patterns along the coastal margin, including the effects of human disturbances on attendance.
4) To study the occurrence of seabirds in marine waters.

Focal Species:
Breeding: Pigeon Guillemot, Pelagic Cormorant, Brandt's Cormorant, California Least Tern, Black Oystercatcher, Western Gull, and Ashy Storm-Petrel*.
*possible breeder, but we have yet to confirm breeding activity at VAFB.
Non-breeding: Rhinoceros Auklet, Brown Pelican, Pacific Loon, Surf Scoter, Brant, Western Grebe, and Sooty Shearwater.

Habitat Type:
Coastal rocks, cliffs, islets and sand dunes.

Partners:
Vandenberg Air Force Base
SRS Technologies

Contact: Dan Robinette

A surveying PRBO biologist.