Hawaiin Petrel in Flight (IMAGE) Smithsonian Caption 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. Credit Copyright Geoffrey Jones 2016, barraimaging.com.au Usage Restrictions News media use of the image files with credit information in relation to the publication in Proceedings of the Royal Society B is permitted. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.