Nest-Box Occupancy by Neotropical Raptors in a Native Forest of Central Argentina

Abstract

Abstract Breeding populations of raptors are sometimes limited by nest-site availability and the use of nest boxes to bolster such populations is widespread. In the neotropical forest, little is known about the ecology of cavity-nesting raptors and their use of nest boxes. Here we examine occupancy patterns of nest boxes by five raptor species during eight years in a semiarid forest of central Argentina: the American Kestrel (Falco sparverius), the Spot-winged Falconet (Spiziapteryx circumcincta), the Tropical Screech-Owl (Megascops choliba), the Barn Owl (Tyto alba), and the Ferruginous Pygmy-Owl (Glaucidium brasilianum). We analyze the influence of vegetation type on nest-box selection, report cases of nest usurpation, and present information on the breeding rates of some of these species. The raptor species showed a marked selection for nest boxes surrounded by grassland, where hunting success may be higher, and avoided those nest boxes placed in habitats dominated by dense shrublands. We observed two ...