California brown pelican
California brown pelicans (Pelecanus occidentalis californicus) visit the Bay in the summer, arriving mostly in April and May and remaining through fall. Most then depart for their breeding grounds located on islands in Baja California, Southern California, and Florida. Brown pelicans feed on schooling fish such as anchovies and smelt. It is always a joy to witness their method of feeding – diving beak first from the air to capture fish under the water. They are the only pelican to feed this way.
Pelicans are social birds and both parents build nests, incubate eggs, and raise young. Brown pelicans used to be listed as endangered due to population declines resulting from hunting (they were killed to avoid fishing competition) and DDT contamination, which caused egg-shell thinning. Brown pelicans were especially vulnerable to thin eggs because, unlike most birds, pelicans incubate their eggs with their feet, essentially standing on the eggs to warm them. Protection efforts have paid off and in 2009 they were de-listed as an endangered species.
Roosting sites provide important habitat value to pelicans and cormorants, and are prone to disturbance because pilings, docks, seawalls, etc. are often located near humans. During the non-breeding season, pelicans can flush at significantly greater distances than during the breeding seasons. Repeated disturbances of major roost sites could lead to declines in regional abundance in an area. To avoid disturbance, move steadily through an area with roosting pelicans rather than lingering and maintain a 164 foot (50 meter) buffer.
Baylands Ecosystem Species and Community Profiles: Life histories and environmental requirements of key plants, fish and wildlife. Prepared by the San Francisco Bay Area Wetlands Ecosystem Goals Project.
The Sibley Guide to Bird Life and Behavior by David Allen Sibley