SEASONAL DISTRIBUTION OF THE AZUREGALLINULE (PORPHYRULA FLA l?1ltOST’Is),WITH COMMENTS ON VAGRANCY INRAILS AND GALLINULES

Specimen records and field observations of the Azure Gallinule (Porphyrulu flavirostris) provide evidence that this species undergoes seasonal movements in portions of its range. Although present year-round in much of Amazonia, it is seasonal in the Guianas, southwestern Amazonia, and Paraguay. Data from single localities within these areas also indicate that this species is seasonal. The existence of five extralimital records supports the hypothesis that this species is migratory. Presence may be timed to correspond with wet or high-water seasons. Unfortunately, the absence of label data on gonad size and fat deposits for the vast majority of the 143 available specimens limits their use in unravelling the seasonal cycle of this species. The preferred habitat of the Azure Gallinule in western Amazonia is extensive areas of marsh grass (Puspafum). An overview of rail and gallinule distribution emphasizes that many species may occur at unpredictable times and places, as might be predicted from their dependence on ephemeral marsh habitats. The two congeners of the Azure Gallinule, Purple and Allen’s gallinules (P. martinica and P. alleni), provide extreme examples of species capable of long-distance, extralimital occurrences. From these points, we conclude that the recent New York (USA) specimen of Azure Gallinule is best regarded as a record of a wild bird.

J. V. REMSEN JR. AND T. A. PARKER III, Wilson Bull., 102(3), 1990, pp. 380-399