![]() ![]() ![]() Though it is known in Adélie penguins in East Antarctica that there is a significant spatial and temporal variability in nest attendance, we found no studies in chinstrap penguins that analyzed these site-specific variations. The method we used to estimate the number of nests is based on the assumption that the ratio of adults and nests in the colonies in the study area and in the colony at Deception Island is similar. We consider the establishment of new colonies during a period of general population decline in the area to be rather unlikely. The two colonies at Unnamed Island #2 and #3 that were newly discovered during this study were very small and may have been overlooked or found irrelevant by the authors of previous studies. The comparison with Shuford and Spear also revealed that the colony at Nancy Rock had been abandoned. The population of the colony at Withem Island had probably also decreased since 1984, but has remained stable since 2013/14. The colonies at Unnamed Islands #1 and Smilets Point decreased by about 45% since 1986/87. Nevertheless, at four colonies, the accuracy of the previous surveys allowed a more accurate estimation of the population change. ![]() However, due to the low accuracy of the previous studies, we do not have strong evidence of a decline. In the southern subarea, the estimated total population in season 1984/85 was 70% larger than in this study. The results proved the suitability of the use of small and lightweight fixed-wing UAVs with electric engines for mapping penguin colonies in remote areas in the Antarctic. However, we also found four chinstrap penguin colonies that have grown since the 1980s against the general trend on the South Shetland Islands. The comparison with previous studies revealed a decline in the total abundance of occupied nests. To model the number of occupied nests based on the number of adults counted in the UAV imagery we used data derived from terrestrial time-lapse imagery. We determined the exact position of 14 chinstrap penguin colonies, including two small unknown colonies, with a total abundance of 35,604 adults. With multiple flights, we covered a total distance of 317 km. We used a battery-powered fixed-wing UAV to survey colonies along a 30-km stretch of the remote coast of southwest King George Island and northwest Nelson Island (South Shetland Islands, Antarctica) during the austral summer 2016/17. Unmanned aerial vehicles (UAVs) have an unprecedented potential for measuring these changes by mapping indicator species such as penguins even in remote areas. Antarctic marine ecosystems undergo enormous changes, presumably due to climate change and fishery. ![]()
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