The Winter Diet of Short-eared Owls in Subtropical Texas: Do Southern Diets Provide Evidence of Opportunism?

Primeras Observaciones De La Dieta Del Búho Orejicorto Asio Flammeus Bogotensis (Strigiformes: Strigidae) en Pichincha, Ecuador

“…Nuestro estudio indica que la dieta de Asio flammeus en Pichincha, Ecuador, está compuesta principalmente por roedores, mayormente especies nativas. Estos resultados coinciden con lo reportado por otros estudios llevados a cabo a lo largo del continente americano (Banfield, 1947;Clark 1975, Rau et al, 1992Hogan et al, 1996;Martínez et al, 1998;Cirignoli et al, 2001;Reid et al, 2011;Williford et al, 2011;Baladrón et al, 2014;Torres et al, 2014). No obstante, se ha reportado que las ratas del género Rattus pueden hacer una importante contribución de biomasa en la época invernal en áreas continentales (Martínez et al, 1998), mientras que en áreas insulares parece consumir mayormente roedores introducidos y aves (de Groot, 1983;Fuentes et al, 1993;Cullen & Smiddy, 2012).…”

“…El Búho Orejicorto Asio flammeus es una especie con amplia distribución mundial (König & Weick, 2008). Su dieta ha sido estudiada en varios continentes, incluyendo Europa (Roberts & Bowman, 1986;Delibes et al, 1991;Cullen & Smiddy, 2012;Kleefstra et al, 2015), África (Djilali et al, 2016), Asia (Lin & Yeh, 2002;Jathar et al, 2011) y Norteamérica (Banfield, 1947;Clark 1975;Holt, 1993;Hogan et al, 1996;Reid et al, 2011;Williford et al, 2011). En América del Sur, los hábitos tróficos de A. flammeus han sido estudiados en Colombia (Borrero 1962), Chile (Rau et al, 1992;Fuentes et al, 1993;Martínez et al, 1998), Argentina (Diéguez, 1996;Cirignoli et al, 2001;Bó et al, 2007;Baladrón et al, 2014) y Paraguay (Torres et al, 2014).…”

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“…Breeding Short-eared Owls prey primarily on small mammals, particularly voles (Wiggins et al 2006, Booms et al 2014. South of the breeding range, wintering Short-eared Owls rely on other prey, and their diet may be more varied (Valdez-Gómez et al 2009, Williford et al 2011. The pellets collected on Otero Mesa in 2014 suggested that the owls preyed heavily on small heteromyids.…”

“…While increased numbers of rodents likely contributed to the Short-eared Owl breeding on Otero Mesa, the low total biomass of the small-mammal community dominated by diminutive pocket mice (weight 6-10 g) may have resulted in owl broods smaller than in areas with larger, more typical prey, where clutch sizes are as high as 11 (Clark 1975, Wiggins et al 2006. These cases of breeding far south of its usual breeding range demonstrate the Short-eared Owl's tendency to nomadism and opportunism (Stone et al 1994, Figueroa-R. et al 2009, Valdez-Gómez et al 2009, Williford et al 2011. The species' nesting is difficult to confirm because of its nocturnal habits, selection of remote areas, reluctance of adults to leave nests, and resorting to defensive behavior only when a threat is very near a nest or young (Wiggins et al 2006).…”

Short-Eared Owl (Asio flammeus) Occurrence at Buena Vista Grassland, Wisconsin, During 1955–2011

“…Short-eared Owl populations vary in synchrony with voles or other cyclic mammals, which the owls track by long-range dispersal (Clark 1975, Korpimäki and Norrdahl 1991, Holt and Leasure 1993, Williford et al 2011). Short-eared Owls have a narrower foodniche both locally and among regions than harriers and most owls (Glue 1977, Jáksic 1983.…”