By 1975, cats and rabbits had been eliminated from Southeast Farallon Island to protect seabird
nesting areas. Although over 400 species of birds have been identified on the
island; the island is truly a seabird colony. In fact the Farallons are the
largest nesting colony south of Alaska. Over 250,000 birds of 13 species nest on the refuge’s 211 acres. Cassin's and Rhinoceros Auklets, California and
Western Gulls, Pigeon Guillemots, Ashy and Leach's Storm-petrels, Tufted
Puffins, Common Murres, Black Oystercatchers, and Brandt's, Double-crested, and
Pelagic Cormorants all nest the islands.
Biologists on the refuge monitor population levels and breeding success of
nesting seabirds each summer. They monitor diet by collecting samples and by observing feeding from blinds. Western gulls are notorious for defending their
territories, killing any bird that strays too close including the chicks of
neighbors. They also readily attack biologists who have to wear hard hats and
rain gear in the summer for protection.
While the seabird season winds down in August, the land bird migration is
gearing up. Of the 400 birds identified on the island, many are land birds that have not been sighted anywhere else in California. In the fall, biologists
net and band birds before sending them on their way. The few trees located on
the island act as bird magnets and help biologists sight and capture the birds.
Most of these trees grow on the leeward side of the two houses on the island,
providing biologists with outstanding birding from the inside of the house.
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Farallon National Wildlife Refuge is managed as part of the San Francisco Bay National Wildlife Refuge Complex.