The Bonin petrel (Pterodroma hypoleuca) is a seabird in the family Procellariidae. It is a small gadfly petrel. 995,000 individuals, about 99% of the total population, breed on the Northwestern Hawaiian Islands, while 5,000 individuals (1% of the population) breed off the coast of Japan on the Bonin and Volcano Islands. Its secretive habits and limited range have resulted in few studies and many aspects of the species' biology are poorly known.