Habitat selection by owls in a seasonal semi-deciduous forest in southern Brazil.

W Menq,L Anjos

doi:10.1590/1519-6984.07614

Abstract

This paper tested the hypothesis that the structural components of vegetation have impact over the distribution of owl species in a fragment of a semi-deciduous seasonal forest. This paper also determined which vegetation variables contributed to the spatial distribution of owl species. It was developed in the Perobas Biological Reserve (PBR) between September and December 2011. To conduct the owl census, a playback technique was applied at hearing points distributed to cover different vegetation types in the study area. A total of 56 individual owls of six species were recorded: Tropical Screech-Owl (Megascops choliba), Black-capped Screech-Owl (Megascops atricapilla), Tawny-browed Owl (Pulsatrix koeniswaldiana), Ferruginous Pygmy-Owl (Glaucidium brasilianum), Mottled Owl (Strix virgata) and Stygian Owl (Asio stygius). The results suggest that the variables of vegetation structure have impact on the occurrence of owls. The canopy height, the presence of hollow trees, fallen trees and glades are the most important structural components influencing owl distribution in the sampled area.

Highlights

Birds of prey, as well as other animal groups, are not evenly distributed in the different habitat types that make up a landscape (e.g. Thiollay, 1994; Granzinnolli and Motta-Junior, 2008)
This study aimed to identify which variables of the vegetation affect the spatial distribution of each owl species the most
The results suggest that M. atricapilla, S. virgata, G. brasilianum and P. koeniswaldiana are more abundant in environments with a greater number of arboreal individuals with CBH between 91 and 150 cm, with fallen trees, Table 1

Summary

Introduction

As well as other animal groups, are not evenly distributed in the different habitat types that make up a landscape (e.g. Thiollay, 1994; Granzinnolli and Motta-Junior, 2008). As well as other animal groups, are not evenly distributed in the different habitat types that make up a landscape Thiollay, 1994; Granzinnolli and Motta-Junior, 2008). Habitat selection by an animal is the result of its ecology, behaviour and physiology, or the interaction of these aspects (Cody, 1985; Tapia et al, 2007). The biology of nocturnal birds of prey, such as owls, is less well known than that of daytime birds of prey, especially regarding habitat use and selection. Some studies conducted in the northern hemisphere have suggested a connection between owl distribution and features of vegetation structure or landscape (Solis Junior and Gutiérrez, 1990; Laidig and Dobkin, 1995; Carey and Peeler, 1995).

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