Brandt's Cormorant is endemic to North America, where it occurs only in marine and estuarine environments. It breeds along the West Coast of North America, reaching Alaska in the north and Mexico in the south. In the main part of its range, from California to Washington, its life history and populations are tied to the rich upwelling associated with the California Current. In the nonbreeding season, when the effects of this current diminish, populations redistribute along the coast in concert with changing water and feeding conditions.
This species nests in colonies on the ground on rocky islets, choosing flat or sloping areas or cliffs with ledges. Nests are large and untidy, made of terrestrial plants or seaweed collected from the land or sea, or stolen from other nests. Courtship behaviors are typical of the genus Phalacrocorax, and emphasize the species' distinctive cobalt blue gular pouch.
Despite its sensitivity to disturbance by humans, Brandt's Cormorant has been well studied. In the past, populations suffered from disturbance related to the market collection of Common Murre (Uria aalge) eggs. Today, although common, Brandt's Cormorant remains at risk from commercial fishing, pollutants, and disturbance associated with the recreational use of the West Coast marine environment. Much has been learned about Brandt's Cormorant since the publication of Bent's life history of this species more than 50 years ago. Long-term monitoring of the population at Farallon Islands, California, the single largest population of this species, has helped elucidate the relationship between breeding success and the El Niño–Southern Oscillation (ENSO), which determines the timing and degree of nutrient-rich upwelling, and hence food availability ( Boekelheide and Ainley 1989 , Boekelheide et al. 1990c ). Colony inventory programs throughout much of the range of the species have facilitated population-monitoring and provided detailed distribution information ( Pitman et al. null , Speich and Wahl 1989 , Carter et al. 1992a .
The naming of Brandt's Cormorant highlights the involvement of Russian naturalists in early North American ornithology. J. F. Brandt, for whom the species is named, of the Academy of Sciences at St. Petersburg, first described Brandt's Cormorant in 1838. His description was based on a specimen, now missing, of unknown origin and unknown collector, which he found among the skins at the Zoological Museum at St. Petersburg. The specimen likely was collected by Russian naturalists during one of several expeditions to the Pacific Coast of North America during the early 1800s ( Mearns and Mearns 1992a ).