Breeding Ecology of Adélie Penguins in Mid Victoria Land, Ross Sea Antarctica

Identifying the factors influencing seabird breeding output is critical for their conservation because breeding performance in turn influences population dynamics. This is particularly important in sensitive environments, where ecological disturbances can lead to changes in population trends of extremely specialized species in a relatively short time. Here, we have reported on the breeding output of the Adélie penguin Pygoscelis adeliae in three colonies of the Mid Victoria Land, Ross Sea (Antarctica), in 2017/2018-2018/2019 to provide scientific information for the Ross Sea Marine Protected Area research and management plan. Breeding chronology, breeding success and chick growth did not differ between study colonies and were in line with data reported for other penguin colonies across Antarctica. Penguin breeding success was higher in central than in peripheral nests and decreased with an increasing number of neighboring nesting skuas; conversely, at-nest weather conditions experienced by chicks did not seem to play a role. Our findings suggest that the quality of the nesting environment seems more important than the general condition of the colony in determining breeding output. Therefore, along with marine habitat characteristics for the planning of management and conservation of seabirds, the importance of the terrestrial environment must be also duly considered.