Emma Risch
Research Mentor(s): Ethan Shirley
Mentor Department: Earth and Environmental Sciences / Museum of Paleontology
Authors: Emma Risch, Ethan Shirley, Mónica Carvalho
Session: Session 2 (10:00am – 10:50am)
Presentation Type: Poster 89
Abstract
South American forests are biodiversity hotspots and critical areas for conservation efforts. As such, forests are expected to have higher animal diversity than unforested areas, and their distribution should reflect moisture, elevation, and temperature conditions. Savannas are distributed irregularly across South America, and while often promoted as important regions for the conservation of biodiversity, they may not have the species richness of nearby forested areas. We mapped distributions of bird species and correlated richness patterns with climate and topography patterns, focusing on comparisons between forested and unforested ecoregions. Data from Birdlife International analyzed in the R epm package show overall bird species richness is generally lower in savannas than in forested areas, but higher than expected in the southern part of the Brazilian Cerrado and lower north of the Amazon River. Seedeaters and generalists are particularly rich in the southern part of the Cerrado, with fewer present north of the Amazon River and in the middle of the Amazon forest. These dietary groups seem to have an outsized effect in driving diversity patterns by deviating from the general trend. Conversely, nectarivores, insectivores, and carnivores follow a pattern of richness that aligns with the expected patterns. Fruit-eaters also exhibit a reduced richness in savannas, implying that this dietary category is principally responsible for the depauperate nature of overall bird biodiversity in those regions and contributes to the increased biodiversity in forested areas. Climate data correlate poorly with bird biodiversity patterns, even though elevation, and patterns of temperature and rainfall are the primary determinants of where savannas are located. A more nuanced approach to biodiversity will build a better understanding of its drivers, and this will help inform conservation decisions.
