Time budget of South African cliff swallows during breeding

Abstract

The use of time by the South African cliff swallow was determined and use of energy calculated by using equations for predicting standard metabolic rate and the cost of flight. The highest daily energy expenditure was during the feeding of nestlings when 9,22 h were spent foraging. The cost of 127 kJ for building a nest is very low if it is considered that the nest is usable for a number of years.