Effects of Human Land Use on Western Burrowing Owl Foraging and Activity Budgets

Abstract

Western Burrowing Owls (Athene cunicularia hypugaea) often live in close proximity to humans, yet their behavioral responses to anthropogenic land use are largely unknown. We compared the diurnal foraging and activity budgets of adult male Burrowing Owls during the breeding seasons of 2004 and 2005 at three urban and three rural sites in northwestern Texas. The owls (N = 17 urban, 10 rural) spent most of their time being vigilant, resting, preening, perching, and in the burrow; less time was spent hunting, eating, provisioning the mate or young, flying, or engaging in other behaviors. Activity budgets did not differ significantly with land use. There were significant differences in activity budgets among study sites and with respect to times of day, weather variables, and numbers of owlets. Although hunting success and provisioning rates did not vary between urban and rural sites, aerial insects were taken as prey more often at urban than at rural sites. More foraging attempts occurred in habitats dominated by forbs, grasses, and bare ground than in areas with woody vegetation or impervious surfaces. Urban sites generally had more human forms of disturbance, but more mammalian and avian predators of Burrowing Owls were observed at rural sites. Our understanding of the behavioral effects of urbanization is still in its infancy, but the study of urban behavioral ecology will likely increase in importance as urban development continues.