Diet of barn owl (tyto alba), spectacled owl (pulsatrix perspicillata) and rufous-banded owl (strix albitarsis) in the western andes of Colombia

Abstract

Dietary studies are one of the most developed research areas in biology and ecology studies of Neotropical owls, but most of these studies have focused on few species. Our study describes the diet of Barn Owl (Tyto alba), Spectacled Owl (Pulsatrix perspicillata), and Rufous-banded Owl (Strix albitarsis) in Jardin and Ciudad Bolivar, western Andes of Colombia. The diet of T. Alba, based on 495 prey items consisted 98.6% of vertebrates, the main food items being rodents (66%) and shrews (21.4%). Out of 142 prey items identified from P. Perspicillata fractured pellets, the main prey species were Artibeus lituratus (23.9%), Rattus norvegicus (21.8%), and Didelphis sp. (16.1%), species of small and medium-sized mammals that tolerate environmental changes and often live in urban areas. Pulsatrix perspicillata preyed also on at least 14 bird species including hummingbirds and migratory birds. Based on 165 prey items S. Albitarsis consumed more invertebrates (57.7%) than vertebrates (42.3%). Among the insects, the main preys were Coleoptera beetles and Orthoptera crickets. Among the vertebrates, the main prey species included mammals such as Thomasomys aureus, Marmosops sp., Marmosa sp., and Reithrodontomys mexicanus. These scansorial species are likely to be vulnerable to aerial predators such as S. Albitarsis which hunt from a perchs. According to standardized Levins index values T. Alba was the most selective in its food habits, P. Perspicillata had intermediate values, while S. Albitarsis showed the least selective diet.