Environmental drivers of vigilance behaviour in painted stork (Mycteria leucocephala) nesting colonies

Abstract

Vigilance in animals, crucial for predator detection, impacts survival and reproduction by diverting time from activities like foraging and mating. Painted Stork (Mycteria leucocephala), a colonially nesting bird, experiences disturbances from avian predators and human presence while nesting in colonies across varied habitats in India. We measured environmental vigilance behaviour at two diverse types of nesting sites in North India, the National Zoological Park and Keoladeo National Park. We studied the study role of several variables viz. sex, nestling age, number of neighbours, number of visitors, and other variables on vigilance, by camera techniques. Our findings revealed significant sex-based differences, with males being more vigilant than females, likely due to their roles in territoriality, mate guarding, and nest protection. Parental vigilance increased as nestlings aged, underscoring its importance as parental investment. Generalized Linear Mixed Models (GLMMs) indicated that number of visitors, number of neighbours, and other habitat variables significantly affected vigilance behaviour. Painted Storks at the National Zoological Park displayed higher vigilance than Storks in Keoladeo National Park, attributed to site specific variables.