Abstract
A time and activity budget for P. haliaetus was constructed to assess the division of labor between sexes during nesting. Females rarely flew during pre-incubation while males flew about one-fifth of the time. Females were usually sedentary during the day. Males delivered most of the nest building materials. Females performed most incubation and brooding while males delivered most of the food. Females fed hatchlings more than males. Little time was spent on aggressive behavior.