Effect of habitat fragmentation on wintering migrants in the Virgin Islands [FINAL REPORT]
Askins RA, Ewert DN, Norton RL. 1988. Effect of habitat fragmentation on wintering migrants in the Virgin Islands [FINAL REPORT]. National Geographic Society
Populations of winter-resident birds were surveyed in the Virgin Islands using fixed-radius point counts. With the exception of one Yellow-throated Vireo, all of the winter residents recorded on these surveys were warblers (Parulinae). Most species of wintering migrants were largely restricted to moist forest and the adjacent moist forest I dry woodland ecotone. Both the density and species richness of migratory warblers were significantly higher in moist forest than in either dry woodland or gardens. Moreover, the average number of species and individuals per survey point was significantly higher in the extensive tracts of moist forest on St. John than in the small remnant patches of moist forest on St. Thomas. Flocking behavior of winter residents was assessed with standardized transect surveys. Most warblers observed during these surveys were participating in mixed foraging flocks. These flocks were composed almost entirely of warblers, and there was no resident nuclear species. Flocks were relatively small, rarely included more than two conspecifics, and occurred both in forest fragments and in large forest tracts.
- Type
- Published Report
- Authors
- Askins, Robert; Ewert, David; Norton, Robert
- Date of Issue
- 1988-12-19
- Publisher
- National Geographic Society
- Units
- VIIS
- Keywords
- Animal Studies, Dry Forest, Habitat Fragmentation, Habitats, Migratory Birds, moist forest, warblers, Winter