Habitat Selection of Dispersing Juveniles of the Main Avian Top Predator of the Andean Montane Forests: Conservation Implications

ZULUAGA, SANTIAGO; VARGAS, F. H.; ARÁOZ, R.; GRANDE, J. M.

Boise, virtual

Conferencia; Raptor Research Foundation 2021 Annual Conference; 2021

Raptor Research Foundation and The Peregrine Fund

Large raptors are the most mobile top predators and in consequence, they are essential components of ecosystem in fragmented landscapes. However, large raptors (e.g., eagles) are also one of the most threatened groups of raptors in the world and are frequently affected by habitat fragmentation. The Black-and-chestnut Eagle (Spizaetus isidori), with a long period of natal dispersal, is a top forest predator of the Andean montane forests. Andean montane forests in the altitudinal band between ∼500 and 3,500 meters (i.e., the altitudinal distribution of the Black-and-chestnut Eagle), has probably lost more than half of its original vegetation cover. Our hypothesis is that habitat selection of dispersing juveniles of the Black-and-Chestnut Eagle will vary according to the remaining native forest, altitude, and slope. We captured six juveniles in four nests of the species within fragmented landscapes of South America (three nests in Colombia and one in Argentina). We tagged them with ~30 gr Global Position System (GPS) with data downloading via Global System for Mobile communication (GSM) (i.e., GPS/GSM loggers). Habitat selection was determined using a resource selection function (RSF). During the first year of natal dispersal, juveniles occupied large home ranges (mean = 996.3 km2; SD± 606; range = 294-2130 km2). While juveniles moved in their process of natal dispersal through fragmented landscapes, they selected areas with higher remaining forest cover, medium altitudes, and higher slopes than the mean available. Our study showed that juvenile Black-and-chestnut Eagles can tolerate a certain level of fragmentation during their period of natal dispersal although they clearly select forested areas. Thanks to the high dispersal capacity of juveniles through fragmented landscapes, Black-and-Chestnut Eagle can still keep essential ecological functions in the fragmented Andean montane forests of South America.