Birds of Kīlauea Point
Brown Booby / Sula sula rubripes / ‘A
Frequently sighted fishing offshore and seen roosting along the Na Pali Coast, but it does not nest on Kaua‘i. In recent years, however, nesting sites have been observed on nearby islands.
Feeds by plunging head first into the water from the air. Usually forages near shore, often within 80 km of breeding grounds. Solitary feeder. Primary prey item is flying fish. Feeding generally occurs during daylight hours.
Breeding season occurs between March and November. Breeds colonially. Nests are located on the ground and consist of a shallow depression surrounded by twigs or other vegetation. An average of two chalky white eggs are layed. Lacks brood patch and instead incubates with feet. Parents share incubation duties. Average incubation shift is 12 hours. Incubation period averages 43 days. The first egg hatches several days before the second. The first chick to hatch ejects the second chick from the nest shortly after it emerges from the egg, so generally only one chick survives. Chick feeding occurs on average once every 17 hours. Fledging occurs 85-103 days after hatching. Post-fledging care and feeding continues for 1-2months.