The Farallon Islands IBA occupies 9,203 hectares of land comprised of: open water and shrubland. The IBA is located in the Northern California ecoregion. It is owned and managed as: federal, and has the following primary uses: non-recreational fishing.

The Farallon Islands IBA contains 12 seabird species and an estimated 256,535 birds. The colony is an IBA for the following species: Black Oystercatcher (30), Brandt's cormorant (17,116), Western Gull (15,127), Cassin's auklet (18,843), Common Murre (199,268), Double-Crested Cormorant (1,122), Ashy Storm-Petrel (1,990), Leach's storm-petrel (1,400), Pelagic Cormorant (504), Pigeon Guillemot (491), Rhinoceros Auklet (516), and Tufted Puffin (128). The following species are on the Audubon WatchList: Ashy Stormpetrel and Leach's Stormpetrel. Farallon Islands are located 34 miles west of San Francisco, spanning over 15 km along the outer continental shelf. The islands are mostly a group of rocks that consist of two main islands with many seas stacks and islets. The two largest islands are Southeast Farallon and West End Island, which together are 110 acres. Cordell Bank is located 20km northwest of the westernmost Farallon islet. Cordell bank is a prominent seamount that is 35 meters in elevations and about 111 km2 in area. The closest area of mainland is Point Reyes, which is 32 km due north of the Farallon Islands.

Ornithological Summary

The Farallon Islands IBA contains 12 seabird species and an estimated 256,535 birds. The colony is an IBA for the following species: Black Oystercatcher (30), Brandt's cormorant (17,116), Western Gull (15,127), Cassin's auklet (18,843), Common Murre (199,268), Double-Crested Cormorant (1,122), Ashy Storm-Petrel (1,990), Leach's storm-petrel (1,400), Pelagic Cormorant (504), Pigeon Guillemot (491), Rhinoceros Auklet (516), and Tufted Puffin (128). The following species are on the Audubon WatchList: Ashy Stormpetrel and Leach's Stormpetrel. The Farallon Islands are one of the most important bird areas in the California Current System with 12 species and 350,000 breeding birds inhabiting it. An estimated 30% of the global Western Gull population breeds on Southeast Farallon Island making Farallon Islands the largest colony of Western Gulls. The islands also the largest worldwide population of Ashy Storm-Petrels which constitutes about 50% of the global population. Some of the largest groups of Brandt?s Cormorants, Pigeon Guillemot and Cassin?s Auklet breed here. Sooty Shearwater feed in the waters surrounding the islands, which are characterized as rich, high productivity water. Common Murre?s also breed in large numbers on the island in numbers exceeding 100,000 individuals on average. The large number of birds and high diversity of species cause the Farallon Islands to often be referred to as the ?Galapagos of California? and the islands remain the most important seabird colony in the Northeast Pacific coast south of Alaska. Ornithological Significance
These islands support an astounding number and diversity of breeding California seabirds, and in 2000, hosted the world's largest breeding colonies of Ashy Storm-Petrel (and some of largest aggregations of breeding Brandt's Cormorant (5800 birds), Western Gull (nearly 10,000 pair), Pigeon Guillemot (800+ pair) and Cassin's Auklet (Abraham et al. 2000).
Population estimates have dramatically changed since 2000, with species both gaining and losing numbers. Brandt's grew from approximately 5,800 birds in 2000 to over 20,000 breeders in 2007 and Common Murres now number close to 250,000, roughly four times the number present in 2000 (Pete Warzybok, via email 2008).
California Gulls colonized the Farallones during 2008. This is the first time this species has been recorded breeding in a wholly marine environment and brings the number of breeding seabird species on the island to 13.
The Farallones are also an important stopover location for many migrant songbirds and a refuge for vagrant species that are lost or blown off course.
Help us learn more about the birds at this IBA! Enter your birding data online at Calfornia eBird! (http://ebird.org/california/)

Conservation Issues

As Farallon Wildlife Refuge, there is limited human disturbance and many laws are in place to help protect the habitat. Altitude restrictions were put in place by the U.S. Coast Guard to limit disturbances to the nesting birds. Fishing still poses some threat, with diving seabirds getting catch in nets and depletion of prey for the birds. Although Farallon Islands are very well protected in regards to human use, introduced plants and animals still threaten species. Cats and rabbits have both been eradicated from Southeast Farallon however house mice still remain on the island. Also exotic grasses are spreading on Southeast Farallon decreasing suitable habitats for Ashy Storm-Petrels. The highest risk to the islands is pollution. As the islands are located just off the coast of San Francisco Bay, they are subject to pollution from untreated storm water, aerial pollutants, surface slicks with toxic chemicals, and contaminated sediments. As a frequently used shipping lane, oils spills are fairly frequent. About half of the ten major oil spills that occurred since 1985 occurred near the Farallon Islands, which have at least impacted Common Murre?s populations. Another potent source of pollution, whose consequences may have a large effect, is the nuclear waste site, which is the first and the largest offshore nuclear waste dump in the United States. Between 1946-1970 more than 47,800 55-gallon barrels of nuclear waste were dumped 25-30 miles west of San Francisco or around the Farallon Islands. The barrels have holes and therefore the nuclear waste is exposed to the seawater. The waters surrounding the Farallon Islands are also home to a 10 thousand ton highly radioactive aircraft carrier, which was sunk in 1951. Because of their location, the Farallon Islands are constantly at risk of pollution and other contaminates.

Ownership

The Farallon Islands IBA is owned and managed as: federal. In 1972, Farallon Islands were made a National Wildlife Refuge and were closed to all visitors except researchers. Point Reyes Bird Observatory became the official caretaker at this time. The US Fish and Wildlife Service currently own the islands and Gulf of Farallons National Marine Sanctuary manage the waters surrounding Farallon Islands. Cordell Bank is part of the Cordell Bank National Marine Sanctuary, which is managed by National Oceanic and Atmosphere Administration (NOAA) and National Ocean Service (NOS). The waters around the islands are managed as the Gulf of the Farallons National Marine Sanctuary (National Oceanic and Atmospheric Administration), and the USFWS owns the islands and manages it as part of the San Francisco Bay NWR Complex. Ecological research on birds is coordinating jointly by USFWS and PRBO.

Habitat

The Farallon Islands IBA is located in the Northern California ecoregion and contains the following habitat types: open water and shrubland. The colony occupies a total land area of 9,203 hectares. On Southeastern Farallon, Farallon weed dominates the available vegetative habitat. A total of 38 plant species live on the Farallon Islands, with only 15 native and the remain species introduced. On the southern quarter of Southeastern Farallon, thick mats of grasses grow on the rocky hills. Most of the other hills on the islands are barren. As of 1980, there were only 3 individual trees on the island, two Monterey cypresses and a single Monterey pine. The islands receive on average 42.7 cm of rain a year, mostly in the winter months between October and April. Frequent fog provides moisture and dampens much of the soil and substrates. The Farallon Islands are a barren cluster of rocks about 30 miles west of San Francisco.

Land Use

The Farallon Islands IBA is used for: non-recreational fishing. As the Farallon National Wildlife Refuge, the Farallon Islands are off limits to people, except for researchers who are working to restore and study seabird and mammal populations.

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