Artificial light is the main driver of nocturnal feeding by the Rock dove (Columba livia) in urban areas

Abstract

Artificial light at night (ALAN) is one of the most extreme alterations of urban areas, which drives nocturnal activity by diurnal species. Although the Rock Dove (Columba livia) is a common species in urban centers worldwide known to have nocturnal activity in urban areas, it is unknown what is the role of ALAN in its nocturnal activity. Moreover, studies that address the relationship between ALAN and nocturnal activity of diurnal birds are scarce in the Southern hemisphere. The objectives of this study were: 1) to evaluate the extent of nocturnal activity in the Rock Dove in large cities of Argentina; and 2) to analyze the influence of ALAN, pedestrian traffic and car traffic on the nocturnal activity in two cities, Buenos Aires and Salta. I visited the most urbanized areas of five large cities in Argentina, and surveyed lighted streets once after 30 minutes after sunset. In Buenos Aires and Salta, I compared environmental conditions between sites were doves were seen feeding with random sites were doves were not recorded feeding. Nocturnal feeding of the Rock Dove was recorded in three of five cities surveyed. ALAN was positively related to nocturnal feeding activity in Salta and Buenos Aires. The results obtained suggest that urbanization promotes a nocturnal activity of the Rock Dove, which occurs in cities located in a vast range of altitudes and biogeographic contexts. Moreover, the nocturnal activity is mainly driven by ALAN, which probably alters the circadian rhythm of doves.