Distance To Cover, Visual Obstructions, and Vigilance in House Sparrows

Abstract

AbstractHouse sparrows (Passer domesticus) feeding away from protective cover decrease their level of vigilance as group size increases. In contrast to recent studies, however, their level of vigilance decreases when feeding farther from cover or in the presence of visual obstructions. These apparent discrepancies reflect the potential complexity in the response of vigilance to various aspects of the risk of predation; scanning need not necessarily increase with the risk of predation. Much work as to the exact nature of the factors influencing vigilance remains to be done before we can fully understand its response to various environmental manipulations.