Chick-provisioning behaviour of the Providence Petrel, Pterodroma solandri

Abstract

This paper provides the first detailed description of the chick-provisioning behaviour of the Providence Petrel, Pterodroma solandri, breeding on Lord Howe Island, New South Wales. Meal size, feeding frequency, timing of feeding, chick weight loss and food conversion efficiency of 5-7-week-old Providence Petrel chicks were determined using 4-h weighing techniques. Chicks were fed mainly at night, with adults returning to the colony during the day only rarely. The mean meal size fed to chicks was 88.55 g, representing 18.2% of adult body mass. There was evidence to suggest that chicks were not accepting all of the food provided to them; those chicks known to receive two feeds in a night were fed less food on their second feed. The minimum amount of food each chick required to maintain constant body mass was 32.04 g of food per day, which is much lower than the average meal size fed to chicks. Chicks received a meal once every 4 days, on average, with the mean interval between successive feeds by the same adult being 7.56 days. This long feeding interval coupled with the low meal size requirements of chicks and the presence of proventricular oil in the chicks' diet suggests that breeding adults are travelling significant distances from Lord Howe Island.