The Hawaiian petrel flies great distances over the north Pacific Ocean to feed, and all the while nitrogen from its diet is slowly integrated into its bone collagen. The birds come to land only to raise their young in the Hawaiian Islands. Ancient petrel bones found in archaeological and paleontological sites in Hawaii and held in the Smithsonian’s National Museum of Natural History preserve stable isotopes of nitrogen in differing proportions that can help scientists understand how the birds’ food web has changed over time. The birds’ ancient bones are a treasury of information about historical change in a large, remote ocean.
Copyright Geoffrey Jones 2016, barraimaging.com.au