[Zoogeography and Taxonomic Relationships of Seabirds in Northern North America]
by
M. D. F. Udvardy
California State University
Sacramento, California 95819
Abstract
The zoogeography and taxonomic relationships among 42 living and 1 extinct species of marine birds from the northern and northwestern coasts of North America are described. Seventeen species are circumpolar in distribution; 17 are endemic to Beringia, and 8 have origins in the North Pacific.
This discussion concerns the northern and western coasts of the continent, from about the Mackenzie Delta westward and southward to the mouth of the Columbia River. Besides bona fide seabirds, I include marine birds that predominantly breed and feed on or around the marine littoral, but exclude two groups: shorebirds, jaegers, and phalaropes, which breed inland and move out from the Arctic after an undetermined postbreeding period; and Anseriformes which become "marine birds" in their southern winter quarters. What remains is 42 living species (Table 1).
The Procellariiformes, or tube-nosed seabirds, have a predominantly southern hemispheric, Gondwanan distribution. The North Pacific basin is an important feeding ground of several shearwaters (Puffinus spp.) that breed in the South Pacific and subantarctic. Only three species breed in the area under consideration: the fulmar (Fulmarus glacialis) and two storm-petrels (Oceanodroma spp.), all of which are still relatively widespread.
Of the Pelecaniformes, the very successful, worldwide cormorants (Phalacrocorax spp.)—inland water as well as coastal and "amphibious" species are on every continent—are ancient Pacific dwellers, with a high grade of endemism here: Of the two subarctic species, one (P. perspicillatus) became extinct long ago, and the other, the red-faced cormorant (P. urile), is very restricted, and deserves our greatest attention. The pelagic cormorant (P. pelagicus), Brandt's cormorant (P. penicillatus), and the double-crested cormorant (P. auritus) are widespread and successful, extending south of the area here considered; double-crested cormorants also breed inland and across toward the North Atlantic coast. As fish-eaters they are often persecuted where coastal fishermen possess firearms, and thus are sensitive to increasing human influence on the coasts.
Two species of arctic geese need special attention. The emperor goose (Philacte canagica) is a Beringean endemic and lives in a very restricted area of both sides of this sea; its status (endangered?) is unknown to me. Since the black brant (Branta bernicla) is a long-range migrant, it is hunted as a game bird at its winter grounds, and subject to management measures. Whereas the emperor goose is a unique offshoot of the genus Anser, the Pacific brant is considered a subspecies; its general distribution is circumpolar.