The Distribution of Seabirds in the Bonin Islands, Southern Japan

Abstract

The Bonin Islands provide breeding habitat for many species of seabird, but detailed information on breeding sites is unavailable. Here, we describe the recent species composition of breeding seabirds on 66 islands. A total of 15 species (Diomedea immutabilis, D. nigripes, Pterodroma hypoleuca, Bulweria bulwerii, Puffinus pacificus, Oceanodroma tristrami, O. matsudairae, Phaethon rubricauda, Sula leucogaster, S. dactylatra, S. sula, Thalasseus bergii, Sterna fuscata, Anous stolidus and A. minutus) was recorded breeding in the Bonin Islands based on field and literature surveys. The sole nesting record of S. sula was on a small island near Haha-jima, where it has failed to breed since a typhoon struck the island. We did not detect Puffinus lherminieri bannermani, although it bred on Kitaiwo-jima before World War II. S. leucogaster was the most widespread species and bred on 39 islands. The second most widespread species was P. pacificus, which bred on 35 islands. There was a positive relationship between species richness and island area. The distribution of breeding sites may be affected by human settlement and introduced species such as feral goats Capra aegagrus. Introduced animals should be controlled to protect the seabird fauna on the islands.