Demography and Natural History of Laysan Albatross on Oahu, Hawaii

Abstract

Laysan Albatross (Phoebastria immutabilis) began re-colonizing sites across the Pacific in the 1970s after severe population declines, and fledged the first chick on the island of Oahu in 1992. We report the status of Laysan Albatross populations at Kaena Point and Kuaokala on the island of Oahu, Hawaii and provide new demographic data for this species. Colonies on Oahu were monitored weekly from 2004 to 2008; all individuals were censused, banded, and genetically identified to gender. There was a population of 365 adults on Oahu in 2008 of which 47% were active breeders. The breeding population increased 27% annually since 1991. The high rate of increase was due primarily to immigration with some local recruitment. Recaptures indicate that seven birds were from French Frigate Shoals, one was from Midway Atoll, and 52 were from Oahu and returning to breed; all other adults were of unknown origin. Hatching rate (62%), fledging rate (78%), and overall reproductive success (48%) were comparable to other colonies despite occasional predation. The rate of adult dispersal was high with up to 10% of birds observed each day on Oahu visiting from Kauai. Adults occasionally changed breeding colonies between seasons, and even visited other islands while actively breeding on Oahu. While small, these colonies are at higher elevations and may serve as refugia in the event of sea level rise and, thus, should continue to be conservation priorities.