Ornithology of the Marshall and Gilbert Islands

Abstract

The avifauna of the Marshall and Gilbert Islands and the sur- rounding ocean consists of 79 species, of which 37 are seabirds and 42 are land and fresh-water birds. Of these 79 species, 20 are recorded here for the first time. One species, a procellarid, is recorded here as a new breeding record for the area. In addition, many species are new records for the 50 atolls and islands located within the area. Collected bird specimens from the Marshall-Gilbert area now total 1,133 (44 species), of which 585 (43 species) were collected by the Pacific Ocean Biological Survey Program. The average number of bird species per island is 13 in the Marshall-Gilbert area. A higher number of species exists in the extreme northern Marshalls than elsewhere in the area; the number decreases southward to the southern Marshalls; an increase occurs in the extreme southern Marshalls and further increases in the Gilberts. This north-south variation may be traced to a number of environmental factors.