The majority of information on storm-petrels comes from studies conducted on land, where these small nocturnal birds come to breed and are accessible to biologists. Few people have the fortune and insight to spend sufficient time on the open ocean studying marine birds to begin to understand the bigger picture of their distribution, abundance, and ecological significance. Larry Spear and David Ainley are among the few who have accomplished this feat. Their monograph on eastern Pacific storm-petrels reports findings from 23 cruises over 26 years covering over 110,000 km² of the eastern Pacific Ocean, stretching from the California Current south through the Humboldt Current and out to 170° W. It summarizes observations of 36,005 storm-petrels from over 9000 hours of observation and provides a comprehensive overview of 23 forms or subspecies of 13 species of this smallest, most pelagic, and widespread group of marine birds. As Spear and Ainley note, “Storm-petrels in the eastern Pacific have a diversity greater than that of any other seabird group in a comparable area of ocean.”