Asian Journal of Environment & Ecology

Birds occupy nearly every terrestrial, freshwater and marine habitat on Earth, and this ecological reach is matched by an extraordinary range of strategies for finding, capturing and processing food. This review brings together recent research on the behavioural, sensory, cognitive and ecological dimensions of avian food acquisition, paying particular attention to how these processes are being reshaped by climate change, habitat modification, urbanisation and pollution. It begins with the theoretical foundations of foraging behaviour, including patch-use and energy-maximisation models, before turning to the sensory systems birds use to detect food, from vision and hearing in raptors and owls to olfaction and remote touch in seabirds and shorebirds. Cognition, tool use and social learning are then considered as mechanisms that allow some species to acquire novel foraging skills, alongside social foraging phenomena such as flocking, information sharing and kleptoparasitism. Later sections address foraging under environmental pressure: polar and marine systems, anthropogenic food subsidies in cities, agricultural intensification, migratory stopover ecology, plastic and light pollution, and thermal constraints on activity, with a further section on frugivory and the mutualistic role that fruit-eating birds play in seed dispersal. A recurring theme is the contrast between the behavioural flexibility that allows many species to persist, and sometimes thrive, amid rapid environmental change, and the vulnerability of specialists whose foraging strategies remain tightly bound to particular sensory cues, prey types or habitat structures. The review closes with a discussion of future research priorities, overall conclusions, and the limitations inherent in a narrative synthesis of this kind.