Impact of Hurricane Hugo on Bird Populations in Virgin Islands National Park

Askins, Robert; Ewert, David

Bird populations were surveyed in Virgin Islands National Park, St. John, U. S. Virgin Islands in 1987 (before Hurricane Hugo hit the Virgin Islands) and in 1990 (four months after the hurricane). Abundance was estimated using the fixed-radius point count method. The average number of individual permanent residents per survey point was significantly lower after the hurricane in both moist forest and dry evergreen woodland. Most of the resident species that showed substantial population declines feed primarily on fruit or nectar, which is consistent with the results of several other recent studies of the effect of hurricanes on forest bird communities. Two species of insectivorous winter residents (Parula amencana and Mniotilta varia) also had significantly lower densities after the hurricane. Although many areas within the park were defoliated after the hurricane, most of the trees remained standing and they produced new leaves ·within a few weeks. Our results suggest, however, that even relatively mild storm damage can result in substantial population declines for some species of birds. Small populations of these species might be vulnerable to extirpation by hurricanes, especially if they are confined to relatively small preserves.