Bird Leg Skin Lesions and Urbanization in a Neotropical Savanna City.

Abstract

Urban sprawl threatens biodiversity and is responsible for significant changes in the species that live in these environments. Given the high cost of comprehensive surveillance, monitoring disease indirectly, such as detecting skin lesions in birds, may help us better understand the prevalence of diseases affecting wild populations. We assessed the frequency of leg skin lesions, as a proxy of disease presence, in 1,565 individuals of 25 species, along the urban matrix of a large Neotropical city, Brasília, Federal District, Brazil. We tested the hypothesis that there is an increase in the frequency of skin lesions in birds due to urban intensification. We observed an increasing trend in some bird species between the frequency of occurrence of lesions and the intensity of urbanization. Species with a higher number of captures had an increase in the percentage of lesions, indicating that the occurrence of lesions may be linked to higher population density or that detection of the effect occurs only when sample sizes are high and controlled among urbanization categories. Our study highlights how the intensity of urbanization may increase the risk of disease transmission for these species. Unfortunately, studies on this topic are scarce in Neotropical regions, despite the region's high biodiversity and urban expansion.