Selección del hábitat de nidificación de la lechuza vizcachera (Athene cunicularia) en agroecosistemas de la Pampa Ondulada

Abstract

The Burrowing owl is a common raptor species in Pampean agrosystems of Argentina, that builds nests in burrows under the ground. Given the negative effect of expanding soybean crops on avian diversity, it is key to study that effect on habitat selection at multiples scales. We investigated the use of nesting habitat before and after the growing of soybean shoots and nesting site selection after the growing of soybean shoots, at three spatial scales: nest scale (habitat type where the nest was located), nesting site scale (a circle of 50 m radius centered on the nest) and home range (a circle of 600 m radius). Surveys were conducted on secondary roads, searching for nests, and 23 random points were established on the same roads to evaluate nest site selection. Habitat use changed with the spatial scale and stage of crop development. Before the soybean shooting, 63% of nests were located into livestock fields, whereas after the soybean shooting, 55% of nests were located in field edges. At the nesting site scale, the cover of habitat types and distance to fences were similar before and after soybean shooting. At the home range scale, Burrowing Owl nested in stubble area and in cropfields before and after soybean shooting, respectively. The Burrowing Owl selected field edges to locate the nest, avoided the proximity of roads and woodlots at the nesting site scale, and selected home ranges close to fences and avoiding trees. We recommend maintaining edges of cropfields with unmanaged vegetation to provide nesting habitat for burrowing owls.