Risk-sensitive foraging by a migratory bird (Dendroica coronata)

Abstract

Because migration is a period of exceptional energy demand, individuals in migratory disposition should be particularly sensitive to variability in food availability, i.e. show risk-sensitivity in their foraging behavior. When given the opportunity to feed at either a constant or a variable reward station, birds in migratory disposition (experimentals) chose the variable reward (risk-acceptance) more often than the constant reward during the premigratory fattening period as they gained weight and accumulated an energy reserve, while control birds not in migratory disposition consistently preferred the constant reward (risk-aversion). Once birds in migratory disposition attained maximum body weight and began to show nocturnal restlessness, their behavior changed and they, too, behaved in a risk-averse manner.