Influence of urbanization on the distribution and defense strategies of the Burrowing Owl Athene cunicularia in the city of Uberl\xe2ndia, southeastern Brazil

Abstract

Urbanization causes drastic changes in habitat and species behavior. In birds, these changes influenced the extinction of some species. The Burrowing Owl Athene cunicularia (Molina, 1782) (Aves: Strigiformes) has achieved some success in its adaptive process in anthropic environments. The main objective of this study was to measure distribution of this species in urban areas. The specific objectives were to quantify and compare the occurrence of this owl and its satellite burrows among urban biotopes; evaluate the importance of satellite burrows as a defense strategy and compare the depth of burrows in different biotopes. Field activities were carried out from August 2015 to November 2016. Sixty areas were sampled in different urban regions. The species was present in 29 of the 60 sites investigated, totaling 112 individuals, 88 adults, 14 young and 10 chicks; 98 burrows were recorded, from which 22 were refuges, seven nests and 67 satellite burrows. Residential and Urban Green Area biotopes had the highest number of individuals and burrows with a significant difference relative to the Commercial/Industrial biotope. A greater number of individuals were found in areas with a high number of burrows showing a positive linear relationship between these variables. The burrows were deepest, on average, in Urban Green Area biotopes. We conclude that the species has a wide distribution in the city with significantly high numbers in the Residential biotope. This same tendency is verified for the distribution of burrows. In areas with a large number of individuals, the same was observed for the number of satellite burrows. Deeper burrows in the Urban Green Areas are perhaps due to the greater transit of people, one of the main features of this biotope and one of the major threats to the Burrowing Owls.