Ridgway's rail (Rallus obsoletus) is a near-threatened species of bird. It is found principally along the Pacific Coast of North America from the San Francisco Bay Area to southern Baja California, as well as in some regions of the Gulf of California. A member of the rail family, Rallidae, it is a chicken-sized bird that rarely flies. Its common name and Latin binomial commemorate American ornithologist Robert Ridgway. This species is closely related to the clapper rail, and until recently was considered a subspecies. It has a long, downward curving bill and is grayish brown with a pale chestnut breast and conspicuous whitish rump patch. The population levels of Ridgway's rail are low due to destruction of its coastal and estuarine marshland habitat by prior land development and shoreline fill. It has year-long, circadian activity and is most vocal nocturnally and crepuscularly. Ridgway's rail pertains to the Rallidae family within order Gruiformes. The California subspecies naturally exists in tidal salt and brackish marshes. These ecosystems are subjected to freely flowing daily tidal flows, a sustainable amount of prey food supply consisting of invertebrates, advanced tidal waterway systems, and apt nesting areas and covered spaces that serve as protection during high tides. The species was officially named by ornithologist James Maley after the renowned ornithologist Robert Ridgway. Habitat Ridgway's rail forages at the upper end of, along the ecotone between mudflat and higher vegetated zones, and in tidal sloughs. Mussels, clams, arthropods, snails, worms and small fish are its preferred foods, which it retrieves by probing and scavenging the surface while walking. The bird will only forage on mudflats or very shallow water where there is taller plant material nearby to provide protection at high tide. At such high tides it may also prey upon mice, and has been known to scavenge dead fish. One of the largest population of Ridgway's rails is in San Francisco Bay, where a total of about 1100 are resident. In the past, however, its geographic range spanned more than 90% of the range of the San Francisco Bay. Other frequent sightings of this species around the San Francisco Bay include the Napa Sonoma Marsh, Bothin Marsh in Mill Valley, Gallinas Creek in San Rafael, Arrowhead Marsh and Damon Marsh in Oakland, the Palo Alto baylands, Charleston Slough in Mountain View, Seal Slough in San Mateo and Belmont Slough. For cover, Ridgway's rail seeks out emergent