Barn owl (Tyto alba) predation on small mammals and its role in the control of hantavirus natural reservoirs in a periurban area in southeastern Brazil

Abstract

The aim of this study was to inventory the species of small mammals in Uberlândia, Minas Gerais, Brazil, based on regurgitated pellets of the barn owl and to compare the frequency of rodent species in the diet and in the environment. Since in the region there is a high incidence of hantavirus infection, we also evaluate the importance of the barn owl in the control of rodents that transmit the hantavirus. Data on richness and relative abundance of rodents in the municipality were provided by the Centro de Controle de Zoonoses, from three half-yearly samplings with live traps. In total, 736 food items were found from the analysis of 214 pellets and fragments. Mammals corresponded to 86.0% of food items and were represented by one species of marsupial (Gracilinanus agilis) and seven species of rodents, with Calomys tener (70.9%) and Necromys lasiurus (6.7%) being the most frequent. The proportion of rodent species in barn owl pellets differed from that observed in trap samplings, with Calomys expulsus, C. tener and Oligoryzomys nigripes being consumed more frequently than expected. Although restricted to a single place and based on few individuals, the present study allowed the inventory of eight species of small mammals in Uberlândia. The comparison of the relative frequencies of rodent species in the diet and in the environment indicated selectivity. The second most preyed upon species was N. lasiurus, the main hantavirus reservoir in the Cerrado biome. In this way, the barn owl might play an important role in the control of this rodent in the region, contributing to the avoidance of a higher number of cases of hantavirus infection.Keywords: Calomys tener, Hantavirus Cardio-Pulmonary Syndrome, Necromys lasiurus, prey selection, Strigiformes.Predação de pequenos mamíferos por suindara (Tyto alba) e seu papel no controle de reservatórios naturais de hantavírus em uma área periurbana no Sudeste do Brasil Resumo O objetivo deste estudo foi inventariar as espécies de pequenos mamíferos em Uberlândia, Minas Gerais, Brasil, com base em pelotas regurgitadas de suindara e comparar a freqüência das espécies de roedores na dieta e no ambiente. Como na região ocorre grande incidência de casos de hantavirose, também se avaliou a importância da suindara no controle de roedores que transmitem o hantavírus. Os dados de riqueza e abundância relativa de roedores no município foram fornecidos pelo Centro de Controle de Zoonoses, a partir de três amostragens semestrais com armadilhas. No total, foram encontrados 736 itens alimentares a partir da análise de 214 pelotas e fragmentos de regurgitação. Os mamíferos corresponderam a 86,0% dos itens alimentares e estiveram representados por uma espécie de marsupial (Gracilinanus agilis) e sete espécies de roedores, sendo os mais freqüentes Calomys tener (70,9%) e Necromys lasiurus (6,7%). A proporção das espécies de roedores nas pelotas da suindara diferiu daquela observada nas coletas com armadilhas, sendo que as espécies Calomys expulsus, C. tener e Oligoryzomys nigripes foram c...

Anomalous colour in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora)

“…Because they represent the base of the trophic web for most of the large and medium vertebrates, small terrestrial mammals suffer a high risk of predation (e.g. Juarez and Marinho-Filho, 2002;Magrini and Facure, 2008;Sousa and Bager, 2008;Abreu et al, 2010). Additionally, anomalous colouration tends to strongly reduce the survival of these organisms, since these deficiencies make them visible to predators (Sazima and Di-Bernardo, 1991;Parsons and BonderupNielsen, 1995).…”

Are avian predators effective biological control agents for rodent pest management in agricultural systems?

“…Another attractive attribute is the fact that small mammals, especially rodents, are the main prey source of barn owls and its diet is an accurate reflection of the local fauna composition as well as population fluctuations of prey (Alvarez-Castaneda et al, 2004;Tores et al, 2005;Granjon & Traore 2007;Magrini & Facure, 2008;Charter et al, 2009). Despite barn owls' relatively smaller size, their high metabolic rate enables them to exhibit a relatively high consumption rate, and are reported to feed up to one fourth of their body weight in prey daily (Marti et al, 2005).…”

Barn owl pellets collected in coastal savannas yield two additional species of small mammals for French Guiana

“…Most authors who have compared inventories of small mammals through pellets analysis and through conventional trapping have concluded that those methods were complementary (Bonvicino and Bezerra 2003, Scheibler and Christoff 2007, Magrini and Facure 2008, Rocha et al 2011. Thus, our results cannot be taken as an inventory of the non-volant small mammals living in the grassy savannas, marshes, and shrublands around Sinnamary.…”