Habitat heterogeneity facilitates resilience of diurnal raptor communities to hurricane disturbance

Abstract

The response of avian communities to hurricane disturbance may differ according to their specific requirements or functional groups, but little is known regarding the response of top-predator birds of prey to these disturbances. We aimed to evaluate the influence of the major Hurricane Patricia on the diversity of diurnal raptors in tropical dry forest, along the coast of Jalisco, Mexico. We conducted raptor surveys at 13 sites located within the eyewall radius of maximum hurricane winds along the path of the hurricane, and 16 sites located outside the hurricane eyewall. We compared the density and species richness of raptors among four habitats of tropical deciduous and semi-deciduous forest, mangroves, and agricultural fields, within the hurricane eyewall and outside the radius of maximum winds. Our results demonstrated a reduction in raptor density in tropical forests within the radius of maximum hurricane winds, where raptor density was significantly lower in deciduous forests within the hurricane eyewall compared to deciduous forests outside the eyewall. Species richness of diurnal raptors was similar among habitats and conditions with the exception that mangroves within the hurricane eyewall had significant higher raptor species richness compared to mangroves outside the eyewall. There was also a significant increase in species evenness, and decrease in similarity, of raptor communities in mangroves and deciduous forest sites within the hurricane eyewall compared to sites outside the eyewall. The reduced density of diurnal raptors in tropical forest sites within the path of the hurricane probably reflects the impact of hurricane winds on forest structure, whereas the increase in species richness and evenness of raptor communities in mangroves within the hurricane eyewall suggests that these habitats could provide a refuge for diurnal raptors following hurricane disturbance. Our results highlight the importance of maintaining landscape heterogeneity of native vegetation to provide alternate habitats for wildlife communities following major disturbance, and facilitate their resilience to extreme climatic events such as hurricanes.