Distribution and Abundance of Seabirds Breeding on the California Channel Islands

The purpose of this paper is to provide an overview of The distribution, abundance, and history of the seabird populations that have bred or currently breed on the Channel Islands of California. Although adjacent to metropolitan Los Angeles and the subject of a large, albeit fragmentary, literature, the marine avifauna of southern California is surprisingly poorly known. Not only are accurate estimates of population size lacking, but often it is difficult to determine whether certain species were breeding or even present on the islands in the past. The recently completed baseline studies of marine birds and mammals of the Southern California Bight, sponsored by the Bureau of Land Management, have provided the first opportunity lor a systematic assessment of marine bird populations in this area. In this paper we (1) provide an update on the status of seabirds nesting in the Southern California Bight; (2) make comparisons of present-day populations with information on prior populations; (3) attempt to assess when and why populations have changed; and (4) discuss some of the interesting zoogeographical aspects of the southern California marine avifauna. It is not our intention that this paper provide the final or complete review of the literature on the history, ecology, or breeding biology of the species in question. Rather, we are providing a synthesis of the results of more detailed studies to be published in the future.