EFFECTS OF HURRICANE GILBERT ON BIRDS IN A DRY TROPICAL FOREST IN THE YUCATAN PENINSULA

On 14 September 1988 Hurricane Gilbert, the strongest tropical storm ever recorded in the Western Hemisphere, passed through an area of tropical forest in Quintana Roo, Mexico, where I had been studying winter bird populations since 1984. The hurricane defoliated the forest, and created a nearly impenetrable rangle of fallen branches and vines at ground level. Point counts and mist-netting conducted 5-6 mo after the storm revealed an influx of field- and shrub-associated bird species. Most previously common insectivores and feeding generalists were present in February-March 1989, but many had declined significantly in abundance. Resident frugivores and nectarivores were especially scarce after the hurricane. Wildfires that swept through northeastern Quintana Roo in the summer of 1989 had a greater effect on birds than did the storm itself. By late winter 1990 the bird community within unburned forest was clearly converging toward its prehurricane composition. In contrast, the bird community in burned forest resembled that associated with recently abandoned agricultural fields and pastures. As a group, overwintering nearctic migrants appeared to be more resilient than year-round residents to the effects of both the hurricane and the associated fires.