Changes in altitudinal distribution of hummingbird diversity between forest and pasture habitats

Climate change has affected the composition of bird communities elevationally in Monteverde, Costa Rica (Pounds et al. 1999). In addition, habitat transformation from forest to pasture has favored weedy species there (Feinsinger 1988). This study sought to combine hummingbird distributions across both habitat type and elevation, as the interaction of habitat disturbance and climate change is not well understood. Past studies have shown changes in hummingbird communities for either climate or habitat changes (Oliver 1993; Donnelly 1998; Smith 2000; Lynn 2001; Winchell 2001; Spear 2004). In order to observe these changes, I hung hummingbird feeders in different elevational zones in both forest and pasture. I found that Purple-throated Mountain Gems (Lampornis calolaemus) have shifted upward in elevation, and Violet Sabrewings (Campylopterus hemileucurus) and Green-crowned Brilliants (Heliodoxa jacula) show trends towards upward movement as well. Also, I observed that the communities of both fields and forest habitats have been altered. I saw no open-area specialist species, very low numbers of any species in pasture sites, and I did not observe some common forest species. My data suggest possible changes in the composition of the hummingbird communities of Monteverde. El cambio climático ha afectado la composición de las comunidades de aves en Monteverde, Costa Rica en términos de elevación (Pounds et al. 1999). Además la transformación del hábitat de bosques a potreros a favorecido ciertas especies de malas hierbas allí (Feinsinger 1988). Este estudio trato de combinar la distribucion del colibrí en función del tipo de hábitat y la elevación, debido a que no se ha entendido muy bien la interacción de la perturbación del hábitat y el cambio climático.https://digitalcommons.usf.edu/tropical_ecology/1028/thumbnail.jp