Foraging and vision

HE task of foraging is a challenging one, but it is not simply a case of a bird poking around aimlessly in the search for food. The bird must offset its energy expenditure against its energy gain. However, aligned with this need to maintain a high-energy output is the requirement to maintain a relatively low body weight. More weight requires more energy to move in flight. Foraging, therefore, accounts for a large proportion of the bird’s daily activity. Indeed, some species may forage more or less from the time they awaken until