A Classification of Recent Birds.
American Museum Novitates 1496: 1-42.
American Museum of Natural History, New York.
Aus der Einleitung:
During the course of incorporating the Rothschild Collection of birds with the general collection of the American Museum of Natural History, an attempt was made to arrive at a natural arrangement for each family or other unit. This often led to rather detailed studies or to intensive efforts to determine the correct position of difficult genera. A number of publications growing from these studies are included in the bibliography (see titles by Amadon, Chapin, Delacour, Mayr, Vaurie, and Zimmer). They relate primarily to Old World families not yet included in Peters' "Check-list" for which no authoritative list exists comparable to Hellmayr's for the New World.
The principal purpose of this paper is to give these findings more general expression. We have of course incorporated the work of others whenever known to us and have included the non-passerine groups, although few changes are made from the now wellestablished sequence of Wetmore (1934, followed by Peters). Indeed we have throughout attempted to make no changes from the established sequence except when they are clearly indicated by recent evidence. Occasion is taken to give a corrected count of species in each family of birds; such a count proved a useful feature of a previous paper by the senior author (Mayr, 1946).
As a result of various discoveries and recent revisions the total number of species in the present list is 8590 as compared with 8616 in the previous one. The change within five years amounts to less than one-half of one per cent. Because of the large number of insular forms of doubtful status, the number of species of birds will always remain an estimate. The final figure may vary by several hundreds either way, depending on the point of view of the enumerator. The five "species" of Todus or the three of Rynchops, for example, might be considered races just as have the former "species" of Anhinga. Further study of continental forms, on the other hand, often gives clear-cut answers as to the racial or specific status of forms previously of dubious status. The result of the two recent counts indicates, however, that the final figure will be within 2 per cent of 8600. For all practical purposes this figure will be satisfactory as a very close approach to the actual number of species of living birds.