Food-niche pattern of the Barn Owl(Tyto alba)in intensively cultivated agricultural landscape

Abstract

This study investigated the dietary niche of the Barn Owl (Tyto alba) in an intensively farmed landscape, based on pellet samples from 12 nesting pairs containing 25 animal taxa and 1,994 prey items after the breeding season in 2016. Based on land use categories of the buffer area around each nest, three landscape types (agricultural, mosaic, urban) were considered, to analyse the diet composition and food-niche parameters. Niche breadth was calculated at the local and landscape level. Small mammals were the most frequent in the diet than other prey in each of the landscape types. The Common Vole (Microtus arvalis), considered to be an important agricultural pest was the most numerous prey in all landscape groups. The trophic niche of Barn Owl varied between 0.69 – 0.86 at the local level, and the overall value of niche breadth was significantly higher in the urban than in the other two landscape types. Our results showed that the increase of Common Vole frequency lead to a decrease in niche breadth; significantly negative relationship was detected between these parameters. Despite differences in niche breadth, similarly high niche overlaps were detected by the randomisation test in the three landscapes. Our results suggest that the diet composition of Barn Owls, mainly their food-niche pattern, reflected prey availability in the comparison of the studied landscapes, which pointed out that it is necessary to examine the dietary difference of Barn Owls at the finer scale of land use.

Diet composition of introduced Barn Owls (Tyto alba javanica) in urban area in comparison with agriculture settings

“…Marti, 1988; Taylor, 1994; Leveau et al, 2006; Bernard et al, 2010; Marti, 2010; Milana et al, 2016). Similar to other food-niche analysis of barn owls in Europe (e.g., Milchev, 2015; Horváth et al, 2018), North America (Marti, 1988; 2010) and South America (e.g. Leveau et al, 2006; Teta et al, 2012), the low values of niche breadth analysis from agricultural areas in this study reflect the high abundance of an available and profitable prey, i.e.…”

“…Common house shrews were the second most consumed prey of barn owls in urban areas. These rodent species are the reported principal prey species in barn owl diet by several studies (Glue, 1967; Love et al, 2000; Hindmarch & Elliot, 2015; Horváth et al, 2018) and this species are more abundant in urban settings compared to agricultural settings (Chang et al, 1999). During tracking of released barn owls, Norway rats and house shrews were observed and frequently encountered in residential neighbourhoods, eateries, garbage dump areas and commercial areas within the study site (personal observation).…”

“…Barn owl diet also depends on the abundance of food supply, prey accessibility, which is affected by habitat characteristics, and general opportunistic feeding strategy (Taylor, 1994; Bond et al, 2005; Horváth et al, 2018; Arlettaz et al, 2010). As opportunistic predators, barn owls will hunt to maximize their nutrient intake and minimize energy expenditure (MacArthur & Pianka, 1966), hence prey size would play an important role in determining barn owl prey selection.…”

Nesting success and productivity of the Common Barn-owl Tyto alba: results from a nest box installation and long-term breeding monitoring program in Southern Hungary

“…The multiannual population cycles of the Common Vole were widely investigated (Jacob et al 2014) and three-year-long population cycles were documented in Europe (Tkadlec & Stenseth 2001, Lambin et al 2006. Predominance of Common Vole was typical in diet of Barn Owls from the pellet analysis which was conducted in Baranya County (Horváth 1999, Horváth et al 2018. The direct monitoring of Common Vole activity in the intensively used alfalfa fields in our investigated area was started in the collapse phase after the 2014 outbreak, based on counting reopened burrow entrances, and detected the next increasing phase of this rodent in 2017 (Somogyi & Horváth 2019).…”

Contribuição Para O Conhecimento Da Dieta De Corujas (Aves: Strigiformes) No Sul Do Brasil

“…porte (Tomazzoni et al 2004, Motta-Junior 2006, Baladrón & Bó 2017. Dessa maneira, o grupo desempenha importante papel biológico (Horváth et al 2018). No Brasil, os estudos que abordam a dieta de Strigiformes concentram-se na região sul e sudeste (Motta-Junior & Alho 2000, Motta-Junior 2002, Scheibler & Christoff 2004, Motta-Junior 2006, Lemos et al 2015.…”