Hummingbird Diversity and Assemblage Composition in a Disturbed Tropical Dry Forest of Guatemala

Abstract

Central American dry forest has experienced high rates of deforestation and intense human-induced disturbance. As a consequence, the remaining forests exist almost entirely as small, degraded, and isolated fragments. Until now, the effect of anthropogenic disturbance on the diversity of Central American tropical dry forest is largely unexplored, making it difficult to understand the consequences for plant and animal communities and the provision of ecological services. Here, we address the impact of small-scale anthropogenic disturbance on local richness and abundance of hummingbirds in a dry forest of Guatemala. To do this, we established 15 point counts on nine transects located within patches of dry forest with different levels of human-induced disturbance. Visits to each site were done twice during the dry season and twice during the rainy season. We found differences in overall number of hummingbird registered between the dry and the wet seasons; we registered higher number of hummingbirds at the end of the wet season and beginning of the dry season, when the availability of flowers was higher. These data suggest that seasonal resource variation could be an important factor influencing the variation in the number of hummingbird present at our study area. Our results also showed resilience of hummingbirds to different levels of disturbance probably related to the generalist behavior of the dominant resident species and the availability of food resources for hummingbirds at different levels of disturbance.