Matthieu Le Corre: Celestial Moderation of Tropical Seabird Behavior (Pew Marine Fellow, 2009)

Most animals, including birds, have cyclic life histories and numerous studies generally conducted on captive animals have shown that photoperiod is the main factor influencing this periodicity. Moon cycles can also affect periodic behavior of birds. Few studies have investigated the influence of these environmental cues in natural settings, and particularly in tropical areas where the change in photoperiod is slight and some bird species keep cyclic behaviors. In a paper published in the November 2011 issue of PLoS ONE Matthieu Le Corre, lecturer at the University of Réunion Island and local coordinator for the Western Indian Ocean Marine Science Association, and colleagues used miniaturized light sensors to simultaneously investigate under natural conditions the influence of photoperiod and moon phases on the migration dates and at-sea activity of a tropical seabird species, the Barau's petrel, throughout its annual cycle. They found that birds consistently started their pre- and post-breeding migrations at precise dates corresponding in both cases to a day-duration of 12.5 hours, suggesting a strong influence of the photoperiod in the regulation of migration behavior. They also found that mean population arrival dates to the colony changed from year to year and they were influenced by moon phases. The authors conclude that this is likely the first study to document a mixed regulation of the behavior of a wild bird by photoperiod and moon phases throughout its annual cycle.

To read the paper, Celestial Moderation of Tropical Seabird Behavior, visit the PLoS One website.