The California Gnatcatcher (Polioptila californica), is a small 10.8 cm (4.25 inches) long insectivorous bird which frequents dense coastal sage scrub growth. This species was recently split from the similar Black-tailed Gnatcatcher of the Sonoran and Chihuahuan deserts.

The male is dusky gray overall, distinguished only by its black crown and thin black beak. It has a long, thin black tail with narrow white tips and edges on the underside of the tail feathers. The female is similar to the male, but with a blue-gray instead of a black crown.

In its range from coastal Southern California south through Baja California and Baja California Sur, this inconspicuous non-migratory resident is most often seen flitting hastily into undergrowth, or heard giving its call, which sounds like a kitten's mew.

Its diet consists of small insects and spiders.

In the northern part of its range (Southern California) this species was listed as Threatened by the United States Fish and Wildlife Service in 1993 due to increasing development in its habitat (current loss of potential habitat in U.S is estimated at 70 to 90 percent (1991, )). Critical Habitat designation under the Endangered Species Act is on hold pending court-ordered review. This species is especially vulnerable because its small populations in a limited habitat often live in the prime land to be developed for housing and commerce. Though some of its habitat has been saved in national forests and state parks, its population has been severely fragmented. There are, however, ongoing efforts to preserve more open land in Southern California to help ensure that this species will not disappear from its former range. California Gnatcatchers are a focal species in many regional habitat conservation planning efforts.