Prey selection and food habits of breeding Burrowing Owls (Athene cunicularia) in natural and modified habitats of Argentine pampas

Abstract

Understanding the way animals respond to novel habitats and fluctuations in food resources can provide insights into the ability of species to settle in modified habitats. We studied the patterns of arthropod selection by Burrowing Owls in natural and modified habitats. We assessed the diet of this owl by means of pellet analysis and, simultaneously, we estimated relative abundance of arthropods in the field by trapping. A similar pattern of prey selection and avoidance was found among habitats, with coleopterans the main prey consumed. Food-niche breadth was low at all habitats, reflecting the dominance of a few prey items in the diet of the Burrowing Owl. Its wide trophic spectrum as well as its ability to take advantage of dominant resources suggests that, from a feeding perspective, the Burrowing Owl can readily colonise and adapt to newly human-modified habitats.

Diet of Nestling Spectacled Tyrants (Hymenops perspicillatus) in the Southeast Pampas Region, Argentina

“…On the other hand, the strong occurrence of orthopterans in the diet towards the end of the reproductive stage could be related to their higher availability then in the study area, especially in January (Cavalli et al 2013). This pattern of seasonal occurrence of orthopterans in birds' diet well represented at the end of the reproductive cycle has been observed for other species in Buenos Aires Province, such as Yellow-winged Blackbirds (Agelasticus thilius) (Darrieu et al 2001) in the northeast and Caracara Chimangos (Biondi et al 2005) and Burrowing Owls (Athene cunicularia) (Cavalli et al 2013) in the southeast of this province. Despite the constant availability of coleopterans in the region from September to January (Cavalli et al 2013), it was a minor source of prey.…”

Does Seasonal Decline in Breeding Performance Differ for an African Raptor across an Urbanization Gradient?

“…gentilis, Rutz, 2008). This is potentially due to their relatively high mobility that could allow them to escape from some of the limitations of urban areas (Chace and Walsh, 2006), while still benefitting from the advantages, such as lower direct persecution (Rutz, 2008) and novel resources like higher abundance of avian prey or nesting sites (e.g., Palomino and Carrascal, 2007;Cavalli et al, 2014;Rullman and Marzluff, 2014;Sumasgutner et al, 2014b). However, some rodent specialists such as Barn owls Tyto alba or Eurasian kestrels F. tinnunculus show decreased fledgling success with increasing urbanization, probably due to decreased prey availability connected to sensory interference due to noise pollution for owls (Senzaki et al, 2016), or nocturnal rodents being harder to locate for a diurnal raptor in an urban environment (Hindmarch et al, 2014;Sumasgutner et al, 2014a).…”

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

“…Por este motivo, en Norteamérica se estudió la selección del hábitat de nidificación en diferentes ambientes y escalas (Lantz et al 2007;Stevens et al 2011;Crowe et al 2013). En la Argentina, la mayoría de los estudios se realizaron sobre la dieta de la lechuza vizcachera en agroecosistemas (Bellocq 1988;Cavalli et al 2014;pero ver Bellocq 1993) y en ambientes áridos (Andrade et al 2010;Carevic et al 2013). En cambio, la selección del hábitat fue menos estudiada.…”

“…Al ser un predador tope cuya dieta incluye pequeños mamíferos (Bellocq 1987;De Tommaso et al 2009;Cavalli et al 2014), las lechuzas regulan poblaciones de roedores vectores de enfermedades que afectan al hombre, como el Síndrome Pulmonar de Hantavirus (Palma et al 2012). Por lo tanto, es fundamental entender qué factores ambientales determinan las dimensiones de su hábitat de nidificación.…”

“…A pesar del disturbio generado por la soja, los resultados sugieren que la lechuza vizcachera pudo adaptarse a dichos cambios. En un estudio sobre su alimentación en hábitats naturales y modificados por el ser humano en la Pampa, Cavalli et al (2014) encontraron que la lechuza vizcachera pudo colonizar y adaptarse fácilmente a hábitats recién modificados por el ser humano, demostrando un comportamiento plástico.…”