Tristram's Storm Petril
Oceanodroma tristrami

SPECIES STATUS:
State recognized as Indigenous
NatureServe Heritage Rank G3 - Vulnerable
North American Waterbird Conservation Plan – High Concern
IUCN Red List Ranking - Near threatened
Regional Seabird Conservation Plan - USFWS 2005

SPECIES INFORMATION: Tristram’s storm-petrel is a large storm-petrel (Family: Hydrobatidae) with long, pointed wings, and a notched tail. Adult males and females are entirely brownish-gray. Flight pattern is typical of storm-petrels--gliding low over water searching for food. Typically forages at night, alone or with conspecifics. Their Hawaiian name, ʻĀkihikēʻehiʻale, translates to “The bird pattering on water” and highlights a unique foraging behavior where it is dipping prey from the ocean’s surface on the wing, often pattering the water with it’s feet. In Hawai‘i, diet includes fish, squid, coelenterates, crustaceans, and insects. Tristram’s storm-petrels are winter breeders, and are nocturnal at nesting colonies. Nests are placed in recesses in rocks, under piles of mined guano, or burrows that they excavate under vegetation. Eggs are laid between December through February and nestlings fledge by June. Little information on parental care of egg or young. Like most storm petrels, age at first breeding is likely three to five years and individuals likely live between 15 and 20 years.

DISTRIBUTION: Tristram’s storm-petrels breed on all NWHI, although they historically bred on MHI as well. Outside of Hawai‘i, breeding colonies only occur on three small Japanese islands. Outside the breeding season, Tristram’s storm-petrels range across the subtropical central and western Pacific Ocean.

LOCATION AND CONDITION OF KEY HABITAT: On Kure, once extirpated by rats, they are a recovering species. Due to difficulties in monitoring burrows, there is an assessment of distribution but no current baseline assessment of abundance.