Terrestrial habitat preferences and segregation of four pinniped species on the islands off the western coast of the Baja California Peninsula, Mexico.

Coastal habitats are crucial to pinnipeds for resting, molting, and reproduction. We examined terrestrial habitat preferences of four pinniped species (California sea lion, Guadalupe fur seal, harbor seal, and northern elephant seal) on the islands off the western coast of the Baja California Peninsula, Mexico. Boat-based surveys were conducted while circumnavigating 10 islands or archipelagos during summer and winter in 2009 and 2010. Habitat selection was inferred based on generalized linear models using animal counts and four habitat descriptors (substrate type, tide pools, bathymetry, and surf protection). The interspecific overlapping was analyzed using the Morisita index. Sea lions, fur seals, and harbor seals used sheltered beaches and rocky platforms as breeding sites. Cobblestone and sandy beaches were the most important substrates for elephant seals. Cliffs were the least preferred habitat by all species. Although substrate preferences were similar among species, segregation was observed in most islands except at the San Benito Archipelago, where sea lions co-inhabit with elephant seals and fur seals. In the context of a recolonization process, these results could provide insights about the location of future colonies and information on habitat use, which can be used when designing conservation strategies for the islands. [ABSTRACT FROM AUTHOR]