Bird Rock is a
rock formation
A rock formation is an isolated, scenic, or spectacular surface rock outcrop. Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term ''rock formation'' can also refer to specific sediment ...
and a small Pacific island west of Tomales Point in
Marin County, California
Marin County is a County (United States), county located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 262,231. Its county seat and ...
that is roughly .
A seabird colony, the island is covered with a layer of
guano
Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...
. Cormorants are common on the island, and
ashy petrels were found breeding there in 1972.
See also
*
Bird Island (Marin County, California)
Bird Island is a small island between Point Bonita and Rodeo Cove in southern Marin County, California.List of islands of California
This list of islands of California is organized into sections, generally arranged from north to south. The islands within each section are listed in alphabetical order.
The Geographic Names Information System (GNIS) lists 527 named islands in the ...
References
Islands of Marin County, California
Islands of the San Francisco Bay Area
Islands of Northern California
Geology of Marin County, California
Uninhabited islands of California
Rock formations of California
Pacific islands of California
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