REPRODUCTIVE BIOLOGY AND BEHAVIORAL ECOLOGY OF ANTARCTIC SKUAS Catharacta maccormicki AND C. lonnbergi.
Keywords:Antarctic seabirds, breeding success, hybridization, siblicide, behavior, cooperative breeding
In the Antarctic (mainland, peninsula and adjacent islands) approximately 40 species of birds are known to breed. Of those, eight are penguins and the others are flying birds. Among the latter, skuas (Catharacta spp.; Stercorariidae) are distinguished for being top predators, territorialists, and by having a widespread distribution. The South polar skua (C. maccormicki) and the Brown skua (C. lonnbergi) are the commonest species of Stercorariidae in the Antarctic. These two species are sympatric in the Peninsula region, interbreed and produce viable and fertile offspring. The present review includes information on basic aspects of breeding, features of reproduction areas, reproductive success, hybridization, cooperative reproduction and behavior during foraging activities, through a critical and comparative analysis of scientific literature and the different geographic regions where these species occur. We consider that quantitative studies, with standard methodology and hypotheses to be tested on behavioral and stress ecology, non-invasive methods of evaluation of environmental contaminations, evaluation of behavioral and populational fluctuations linked to local and global climatic changes and to human presence must be a priority, especially in breeding areas where no studies have been done.