SEGREGATION IS KEY IN THE SURVIVAL OF ANTARCTIC PETRELS
According to niche theory, mechanisms exist that allow co-existence of organisms that would otherwise compete for the same prey and other resources. How seabirds cope with potential competition during the non-breeding period is poorly documented, and had been particularly little studied for small species scientists say.
Spanish researchers conducted the study in the sub-Antarctic island of Bird Island in the archipelago of South Georgia, placing geolocators by light levels in 100 individuals of four species of petrels: Pelecanoides urinatrix, Pelecanoides georgicus, Pachyptila turtur and Halobaena caerulea; small birds that feed primarily on krill, during the non-breeding period. During the breeding season, the scientists collected geolocators with the registered information for all the positions of the marked birds for a year.
The results show a clear spatial segregation and segregation in the niche between the species studied, showing new signs of ecological mechanisms, primarily related to the reduction in competition for food resources during the non-breeding period, which would explain the coexistence of these abundant subantarctic predators in common nesting areas, "adds Navarro who leads the study.
Joan Navarro et al. 2015. Spatial distribution and ecological niches of non-breeding planktivorous petrels. Nature
Photo: Blue petrel by Ruth Brown
