North America's only small black-and white flycatcher, and a common breeding species from California through the southwestern United States to Middle and South America, the Black Phoebe is invariably associated with water. Coastal cliffs, riverbanks, the shorelines of lakes and ephemeral ponds, cattle tanks, and fountains in parks are all favored habitats. Almost any semipermanent source of water with an accompanying source of mud, required for nest construction, is attractive to this species. In many areas, natural nest sites, such as sheltered rock faces, streamside boulders, and hollow cavities in trees, have largely given way to artificial nest sites provided by human-made structures. Such artificial sites have greatly increased breeding densities of this species in habitats where the lack of suitable nest sites once limited breeding. The traditionally limited availability of suitable nest sites has promoted strong nest-site tenacity in this species; individuals often reuse the same nest or nest site year after year.
Black Phoebes are monogamous and frequently raise 2 broods of young during a breeding season. Their adherent nests are composed of a mud shell lined with plant fibers, typically placed over water and plastered to a vertical wall within a few centimeters of a protective ceiling. Nest construction or refurbishment usually begins in March or April and takes from 1 to 3 weeks. After hatching, the altricial nestlings are brooded by the female for several days, are fed by both adults, and fledge in about 18 days. After breeding, some individuals wander, tending to move downslope to lower elevations, but these patterns of movement are not nearly as pronounced or well known as those of the Say's (Sayornis saya) and Eastern (S. phoebe) phoebes.
Primarily an insectivorous species, the Black Phoebe forages in open areas over water, grass, or other substrates. It is a versatile forager, sallying from perches within a few meters of the ground and hawking prey from the air or gleaning it from the ground or the surface of a pond. Individuals are known to snatch small minnows from just below the water's surface and, rarely, to eat small berries.
Since Bent's ( Bent 1942b ) summary of the literature, various aspects of the biology of the Black Phoebe have received extensive attention from researchers in California and Texas. These studies have focused primarily on reproductive biology ( Irwin 1985 , Schroeder 1985a , Wolf 1991 ), song and behavior (Smith Smith 1970g , Smith 1970f ), and foraging ecology (Verbeek Verbeek 1975a , Verbeek 1975b , Ohlendorf 1976 , Irwin 1985 ). Migratory biology, physiology and molt, and other facets of the life history of this species remain poorly known, however, especially in Middle and South America.