Miniature gps data loggers reveal habitat affiliations and movement of veeries (catharus fuscescens) during their first non-transient period in south america

Abstract

The ecology of Nearctic-Neotropical migrant songbirds in South America is largely unexplored. We used miniature global position-ing system (GPS) data loggers to determine the broad habitat associations of nine Veeries (Catharus fuscescens) during their first non-transient period in South America. Because Veeries undertake an intra-tropical migration between two separate non-transient periods, the habitat used by settled birds in South America cannot be determined from field observation or the capture of single unmarked individuals. Using satellite images, we examined coarse habitat characteristics at GPS positions from the tagged birds during their first non-transient period (December to February). We also examined habitat descriptions from existing records (e.g., published literature, museum records) of multiple birds from single sites that we considered settled individuals. All records we accepted as birds settled during their first non-transient period, including birds we tagged, were associated with stunted forests on nutrient poor soils, primarily on elevated cerrado and white sand enclaves (∼200 to 750 m) on the Brazilian Shield in southern Amazonia (cerrado, cerradão, savana metalófita-canga, campinarana, sartenejal). Notably, these forest communities are geographically limited and severely threatened due to anthropogenic conversion and occur largely in an ecologically distinct and highly threatened transitional biome between the Brazilian Cerrado and Amazonian lowlands (the Cerrado-Amazonia transition). Therefore, and considering the species' recent population decline, we believe the Veery's current global con-servation status should be reconsidered. Following Nearctic-Neotropical migration, tagged individuals exhibited three behaviors prior to intra-tropical migration: (1) a prolonged stationary period at a single site, (2) shorter stationary periods with relocation events, and (3) apparent continual movement. Our results have significant importance in terms of understanding the ecology and conservation needs of this declining species and demonstrate the utility of GPS loggers in tracking songbirds through dense tropical vegetation in remote and inaccessible regions of South America.