Avifauna of the Cayerias of Southern Cuba, with the Ornithological Results of the Paul Bartsch Expedition of 1930. Smithsonian Contributions to Zoology. Number 477.

摘要

The systematics and distribution of the avifauna of the numerous small islands scattered along the southern coast of Cuba are analyzed and discussed using a previously unstudied collection made by Paul Bartsch in 1930 and reports in the literature. Estimates of eustatic sea-level change indicate that this avifauna is no older than mid- to late Pleistocene, as the islands were doubtless submerged during earlier Pleistocene sea-level maxima. The cays were colonized from Cuba over water gaps at different times since their last emergence and over broad land connections probably during the Wisconsinan glacial age to as recently as -8000 years ago. The avifauna is a depauperate sample of that of the Cuban mainland, comprising 28 species of resident land birds. Twenty-three (82%) of these are widely distributed elsewhere in the Antillean-Bahaman region. Only 3 (11%) of the 28 species are confined to the Cuban region: Xiphidiopicus percussus, Vireo gundlachii, Teretistris fernandinae. For the small scrub and mangrove covered islands in the Golfo de Guacanayabo, 8 of the 9 resident species (89%) are widespread. The occurrence of 25 species of land birds on Cayo Cantiles (the largest number on any island of the southern cayerias), in contrast to only 17 on the larger island of Cayo Largo, reflects the importance of habitat diversity over island area in determining species richness. Both islands have reasonably well-known avifaunas. No species is endemic to the cayerias, but five have differentiated at the subspecific level within the islands: the woodpeckers Melanerpes superciliaris and Xiphidiopicus percussus, the flycatcher Contopus caribaeus, the vireo Vireo gundlachii, and the blackbird Agelaius humeralis. Populations of two other species, the thrush Turdus plumbeus and the grackle Quiscalus niger, appear to represent relict forms that have been largely replaced by other subspecies on mainland Cuba. Several puzzling patterns of distribution include the presence of Agelaius humeralis on Cayo Cantiles and in the Jardines de la Reina and its absence on the much larger Isle of Pines; the absence of the dove Columbina passerina from the Jardines de la Reina; and the absence of the flycatcher Tyrannus caudifasciatus from Los Canarreos.