The Causes of Death of Two Sub-adult Black-footed Albatrosses Returned to Torishima, Izu Island

Abstract

The causes of death of albatrosses are not well documented, owing to them breeding on remote uninhabited islands. During the chick-rearing season in late February 2004, two sub-adult Black-footed Albatrosses were found dead at Hatsunezaki colony, Torishima, Izu Islands. This locality holds the largest breeding population of this species in the western North Pacific. Leg bands indicated both birds to have been fledged at the same colony on the island in the early 2000s; one was 25 months old and another was 37 months old. The former was found to have a broken humerus and clavicle, and we therefore posit that it had died after crashing to the ground in the strong wind turbulence that had prevailed above the colony during the two days prior to discovery of the corpse. The latter individual was diagnosed with enteritis and ulcers throughout the small intestine, which probably resulted in its death.