Changes in bird communities of Admiralty Bay, King George Island (West Antarctic): insights from monitoring data (1977–1996).

Abstract: The paper summarizes results of twenty years of seabird observations carried out between 1977 and 1996 on the western shore of Admiralty Bay (King George Island, South Shetlands, Antarctic). Changes in population size, distribution and phenology of the breeding species as well as the appearance of non-breeding species are reported. A total of 34 species of birds were observed, including 13 breeding species. Among the non-breeding species, four were observed to visit the site regularly, six rarely, and the remaining 11 were observed only occasionally. Among breeding populations, three Pygoscelis penguin species, the main krill consumers, were most numerous. The Adélie Penguin (P. adeliae) dominated among the penguins nesting in the investigated areas, reaching 23,661 breeding pairs in 1978. Two other penguin species were less abundant with population sizes of approximately 7,200 breeding pairs for the Chinstrap Penguin (P. antarcticus) and 3,100 breeding pairs for the Gentoo Penguin (P. papua) in the same year. During the following two decades, breeding populations of pygoscelid species experienced a declining trend and their numbers were reduced by 68.0% for Chinstrap, 67.1% for Gentoo, and 33.9% for Adélie Penguins. The data reported here represent a unique reference basis and provide valuable information about indicator species, suitable for comparison with contemporary observations of bird populations in the Antarctic Peninsula region, a place of rapidly occurring climate changes and intensive harvesting of marine living resources

What affects the probability of biological invasions in Antarctica? Using an expanded conceptual framework to anticipate the risk of alien species expansion

Successful alien species invasion depends on many factors studied mostly in post invasion habitats, and subsequently summarized in frameworks tailored to describe the studied invasion. We used an existing expanded framework with three groups of contributing factors: habitat invisibility, system context and species invasiveness, to analyze the probability of alien species invasions in terrestrial communities of Maritime Antarctic in the future. We focused on the first two factor groups. We tested if the expanded framework could be used under a different scenario. We chose Point Thomas Oasis on King George Island to perform our analysis. Strong geographical barrier, low potential bioclimatic suitability and resource availability associated with habitat invasibility significantly reduce the likelihood of biological invasion in Antarctica. An almost full enemy release (low pressure of consumers), the high patchiness of the habitat, and the prevalence of open gaps also associated with habitat invasibility increase the possibility of invasion. The dynamics of functional connectivity, propagule pressure and spatio-temporal patterns of propagule arrival associated with human activity and climate change belonging to the system context contribute to an increase in the threat of invasions. Due to the still low land transport activity migration pathways are limited and will reduce the spread of alien terrestrial organisms by land. An effective way of preventing invasions in Antarctica seems to lie in reducing propagule pressure and eliminating alien populations as early as possible. The expanded conceptual framework opens up wider possibilities in analyzing invasions taking place in different systems and with multiple taxa

Antarctic fur seal (Arctocephalus gazella) annual migration and temporal patterns of on-shore occurrence of leucistic individuals on King George Island.

Non-invasive tracking the on-shore occurrence of the atypically pigmented animals and determination of land residency duration of leucistic seals would help us find out more about the rotation of the migrating population. During seven austral summer seasons (2011–2018), by counting the animals every 10 days at the Cape Lions Rump shore, King George Island, South Shetlands, in the Antarctic Specially Protected Area No. 151 and the adjacent ice-free land (31.52 km2) we registered fourteen leucistic individuals per a total of 43,919 animals. Moreover, daily monitoring of local fauna resulted in further 33 leucistic animals (together 47, in all seasons). Whilst the results of 10-day censuses of the total population were similar inter-seasonally, a tendency for increased occurrence of leucistic individuals in successive seasons was revealed. Generally, the number of animals increased significantly as season progressed. Since leucistic individuals stayed on-shore for 1–2 days usually, it can be hypothesised that the observation of migrating Antarctic fur seals every 3 days does not involve the same individuals. Also, additional every 5-day censuses taken in one season in ASPA 151 resulted in a higher seasonal number of animals, which proves that more frequent counts help us estimate population abundance more efficiently. Thus, every 5-day counts are proposed as a feasible and justified method of population monitoring

Pygoscelid penguins breeding distribution and population trends at Lions Rump rookery, King George Island

Abstract: Long term changes (46 years) in the abundance of pygoscelid penguins breeding populations and nests distribution in the Lions Rump (King George Island) colony were in− vestigated in three time intervals, according to previously published two censuses and one original study conducted in 2010. At that time a detailed colony map based on the GIS system was made. Results of this study showed different trends for each investigated species. In the last three decades Adélie penguin breeding populations showed strong declining tendencies (69.61%). In contrast, the population of gentoo penguins represents the reverse trend, increas− ing 171.85% over the same period. Observed changes in both penguin population sizes are re− flected in the different spatial and geographic distribution of their nests. The population changes observed at the Lions Rump colony are consistent with the relevant pygoscelid pen− guin tendencies in the western Antarctic Peninsula region. Breeding penguin population dy− namics at Lions Rump area with a minimal disturbance by human activity may well illustrate a natural response of those birds to environmental changes in the Antarctic

Are the diets of sympatric Pygoscelid penguins more similar than previously thought?

In recent years, functional changes in Southern Ocean are becoming more noticeable, due to climate change and increasing human impacts, including a growing fshery that is concentrating in the Antarctic Peninsula (AP) region. Antarctic krill Euphausia superba is often the primary prey species for animals such as Pygoscelis penguins, a sentinel species for ecosystem monitoring and management. During the last two decades in the AP gentoo penguin numbers (Pygoscelis papua) have increased and their range has shifted southward, in contrast to the decline in numbers of Adélie (P. adeliae) and chinstrap (P. antarcticus) penguins. Given divergent population trends, the goal of this study was to examine diferences in their diet, and size structure of Antarctic krill recovered from penguin diet samples. The study is based on diet samples collected during the austral summers on King George Island (South Shetland Islands) where P. adeliae, P. antarcticus, and P. papua breed in mixed colonies. Results indicate that the penguins consumed krill of similar sizes during the breeding period. In contrast to prior diet studies, we found higher proportions of krill in the gentoo diet and changes in the percentage of krill in the diet relative obtained during 1970s. The similarity in diets among all three species suggests that the availability prey items (e. g., fshes) may be changing and driving higher dietary overlap. Moreover, we also check diferences in krill length among penguin individuals and we did not fnd any statistically signifcant diferences. We also found plastic debris in penguin stomachs during both summers

Mapping Glacier Forelands Based on UAV BVLOS Operation in Antarctica

The aim of this article is to show geomorphological mapping of remote Antarctic locations usingimagestakenbyafixed-wingunmannedaerialvehicle(UAV)duringtheBeyondVisualLineof Sight (BVLOS) operations. We mapped landform assemblages developed in forelands of Ecology Glacier (EGF), Sphinx Glacier (SGF) and Baranowski Glacier (BGF) in Antarctic Specially Protected Area No. 128 (ASPA 128) on King George Island (South Shetland Islands) and inferred about glacial dynamics. The orthophoto and digital elevation model allowed for geomorphological mapping of glacial forelands, including (i) glacial depositional landforms, (ii) fluvial and fluvioglacial landforms, (iii) littoral and lacustrine landforms, (iv) bodies of water, and (v) other. The largest area is occupied by ground moraine and glacial lagoons on EGF and BGF. The most profound features of EGF are the largelatero-frontalmoraineridgesfromLittleIceAgeandthefirsthalfofthe20thcentury. Largeareas of ground moraine, frequently fluted and marked with large recessional moraine ridges, dominate on SGF. A significant percentage of bedrock outcrops and end moraine complexes characterize BGF. The landform assemblages are typical for discontinuous fast ice flow of tidewater glaciers over a deformable bed. It is inferred that ice flow velocity decreased as a result of recession from the sea coast, resulting in a significant decrease in the length of ice cliffs and decrease in calving rate. Image acquisition during the fixed-wing UAV BVLOS operation proved to be a very robust technique in harsh polar conditions of King George Island

Rapid environmental changes in the western antarctic peninsula region due to climate change and human activity

The Antarctic and the Southern Ocean are a critically important part of the Earth system. The climatic, physical, and biological properties of this region are closely linked to other parts of the global environment. 200 years of direct human impact, recent climate amelioration and changes in the main sources and circulation of biogenic compounds as well as accumulation of industrial contaminants have significantly affected the whole ecosystem. Particularly sensitive is the region of the Western Antarctic Peninsula, which is considered to be one of the hot spots of the Earth. In this paper, we review recent literature and compare it with historical data to estimate and predict the consequences of this process. The Antarctic ecosystems can no longer be regarded as pristine. Global as well as local human influence has transgressed the barriers isolating that continent from the rest of the World, causing previously observed changes to accelerate

Individual variation in migratory movements of chinstrap penguins leads to widespread occupancy of ice-free winter habitats over the continental shelf and deep ocean basins of the Southern Ocean

A goal of tracking migratory animals is to characterize the habitats they use and to interpret population processes with respect to conditions experienced en route to, and within, overwintering areas. For migratory seabirds with broad breeding ranges, inferring population-level effects of environmental conditions that are experienced during migratory periods would benefit by directly comparing how birds from different breeding aggregations disperse, characterizing the physical conditions of areas they use, and determining whether they occupy shared foraging areas. We therefore tracked 41 adult and juvenile chinstrap penguins (Pygoscelis antarctica) from three breeding locations in the northern Antarctic Peninsula region during the austral winter of 2017. The satellite tracking data revealed overlap of individuals over continental shelf areas during autumn months (MarMay), shared outbound corridors that track the southern Antarctic circumpolar current front, followed by occupancy of progressively colder, deeper, and ice-free waters that spanned the entire western hemisphere south of the Polar Front. Despite broadly similar physical environments used by individuals from different colonies, the proportion of birds from each colony that remained within 500km of their colony was positively correlated with their local population trends. This suggests that local migration strategies near the Antarctic Peninsula may benefit breeding populations. However, the magnitude of intercolony and intra-colony overlap was generally low given the broad scale of habitats occupied. High individual variation in winter movements suggests that habitat selection among chinstrap penguins is more opportunistic, without clear colony-specific preference for fine-scale foraging hotspots. Mixing of individuals from multiple colonies across broad regions of the Southern Ocean would expose chinstrap penguins from the Antarctic Peninsula to a shared environmental experience that helps explain the regional decline in their abundance