Survival, habitat use, and movements of fledgling white-throated robins in tropical agricultural habitat

I used radio-telemetry to study the behavior of White-throated Robins (Turdus assimilis) during the postfledging dependent period. The study was conducted in a mixed agricultural and forested landscape in southern Costa Rica from March through August of 2001 and 2002. One fledgling per brood was located daily until dispersal from the natal area. I compared survivorship, habitat use, and movements for fledglings from nests in coffee plantations and cattle pastures. Birds that fledged from nests in pasture moved into forest more quickly and were more likely to survive until dispersal from their natal areas than were birds from nests in coffee. Pasture habitat was rarely used during the postfledging period while coffee and forest were used extensively. Fledglings that remained in agricultural habitats were less likely to survive until dispersal than were those that moved into forested areas. Average daily distances from the nest gradually increased until fledglings dispersed away from their natal areas, always into forest, and were not different for birds from pasture or coffee. While the species can nest successfully in agricultural habitats, the use of forest positively influenced survivorship of young during the postfledging dependent period.