The western Antarctic Peninsula is characterized by pronounced climate variability and a high concentration of human activities, including tourism and fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the body responsible for the conservation of Antarctic marine ecosystems and for regulating fisheries south of the Antarctic Convergence, considers Pygoscelis penguins to be key ecosystem indicator species. In this study, we used stomach content analysis and tracking data to examine diet composition and foraging parameters of chinstrap (Pygoscelis antarcticus) and gentoo (Pygoscelis papua) penguins breeding in two colonies at Cierva Cove, Gerlache Strait (64°08′ S, 60°59′ W and 64°10′ S, 60°56′ W, respectively). Our aim was to identify their main prey and the areas they use during foraging trips in the chick-rearing period of the 2024/25 breeding season. Antarctic krill (Euphausia superba) dominated the diet of both species; however, chinstrap penguins consumed smaller krill than gentoo penguins. Tracking data showed that both species foraged in coastal areas, with chinstrap penguins undertaking shorter trips, both distance and duration than their congeners. This study provides updated, spatially explicit ecological information to support management and conservation in the Gerlache Strait, a region increasingly pressured by krill fisheries.

In the context of the looming biodiversity crisis, adding patches of habitat has been proposed as a restoration strategy in several ecosystems. However, these interventions rarely mimic the conditions of the natural habitats precisely. Consequently, not all species equally benefit from the restored habitat, fostering a difference in species fitness. Using a metapopulation model with a competition-colonization tradeoff, we explore how the introduction of habitat patches where the competition ability of the superior competitor is either enhanced or diminished affects species coexistence. We show that adding habitat changes the coexistence regime at the regional scale, potentially leading to undesired consequences. Our results suggest that inferior competitors with colonization rates close to the lower bound that enables coexistence are particularly vulnerable to this kind of interventions. The impact on the coexistence regime is also dependent on the amount of habitat restored as well as the extent to which the new habitat distorts the competitive capacity of the superior competitor. Our results highlight the double-edged sword effect of suboptimal restoration, revealing potential unintended consequences that could exacerbate biodiversity loss. On the other hand, restoration favoring endangered species is also identified as a conservation tool. The present study advances in the mechanistic comprehension of habitat restoration, a necessary endeavor in the face of the challenges posed by global change.

The foraging behavior of bioindicator species, such as penguins, provides valuable insights into ecosystem functioning, helping to assess the potential effects of environmental variability and identify priority areas for their conservation. At Stranger Point/Cabo Funes (South Shetland Islands), Antarctic krill (Euphausia superba) dominates the diet of chick-provisioning Adélie (Pygoscelis adeliae) and gentoo (Pygoscelis papua) penguins. However, the marine areas used by these species had not previously been studied using GPS loggers. During the 2017/2018 chick-guarding stage, we tracked the horizontal movements of both species. The individuals predominantly moved southeast of the colony, remaining in nearby coastal habitats within the Mar de la Flota/Bransfield Strait. Maximum and total distance traveled, as well as foraging trip duration, did not differ significantly between species. However, differences were observed in trip departure times, with gentoo penguins departing earlier in the morning than Adélie penguins. Both species overlapped in their home range areas, but there was evidence of some spatial segregation: foraging effort of gentoo penguins was more concentrated closer to the colony than that of Adélie penguins. In contrast, no significant differences in trip parameters were observed in either species as the breeding stage progressed, suggesting that krill was not a limited resource during the 2017/2018 season. In line with this, no interspecific differences in breeding success were detected. Our results underline the ecological value of the coastal waters off Stranger Point, where a seamount lies about 20 km offshore, as productive foraging grounds and reinforce the importance of conserving these key habitats.

Deep uncertainty and ignorance, particularly “unknown unknowns”, represent fundamental challenges in the conservation and management of the Southern Ocean. Conventional fisheries management approaches, based on known data and predictive models, may underestimate the risks posed by complex ecological interactions and rapidly changing environmental conditions. This paper argues that acknowledging and explicitly addressing uncertainty is essential for effective and precautionary decision-making in this region. The integration of MPAs into the broader krill management framework is not only strategic but necessary to navigate epistemic blind spots and ontological uncertainty. Acknowledging what we do not, and cannot, fully know is a prerequisite for responsible stewardship of the Southern Ocean. MPAs provide a precautionary foundation for managing marine ecosystems under conditions of irreducible uncertainty.

Understanding long-term population trajectories is essential for effective wildlife management, particularly in exploited species. In Uruguay, the South American sea lion was subjected to intense commercial harvesting throughout much of the 20th century; however, post-exploitation population trajectories remain poorly documented in the country. We assessed long-term demographic trends of the two main Uruguayan rookeries, Isla de Lobos and Cabo Polonio, both Marine Protected Areas, by compiling historical pup counts (1953–2000) and conducting standardized aerial photographic surveys in 2011, 2013, and 2017. Pup abundance was estimated from aerial mosaics, corrected for detection bias, and analysed using log-linear regression to estimate annual rates of change. Between 1956 and 2017, pup production in Uruguay declined significantly at a mean annual rate of 1.9%. Cabo Polonio remained relatively stable, exhibiting only a weak and non-significant decline (–0.7% yr⁻¹), whereas Isla de Lobos showed a strong and significant annual decline of approximately 5.0%. In 2017, estimated pup abundance reached 2006 at Cabo Polonio and only 299 at Isla de Lobos. These contrasting trajectories likely reflect the legacy of intensive commercial exploitation at Isla de Lobos, where approximately 47,000 pups were removed over 24 years, followed by the continued extraction of live non-breeding individuals for zoos and aquariums. Limited demographic rescue between colonies, ongoing anthropogenic pressures, and recent stochastic events (including the 2023 outbreak of highly pathogenic avian influenza (HPAI H5N1)), further increase vulnerability of the Uruguayan colonies. Our findings underscore the need for sustained monitoring and colony-specific management to promote long-term population resilience in Uruguay.

Abstract Antarctica is facing intensifying pressures from climate change, industrial fishing, tourism and renewed geopolitical competition, even as scientific activity on the continent reaches unprecedented levels. We argue that this proliferation of research often fails to deliver the integrated, policy‐relevant knowledge needed for precautionary governance, producing what we define as epistemic opacity: a structural misalignment between knowledge production and decision‐making, producing data‐rich but insight‐poor knowledge systems. These weaknesses are magnified by funding systems that prioritize short‐term projects rewarding novelty and visibility over continuity and institutional responsibility, as well as systematic biases in long‐term monitoring. Antarctic science produces vast knowledge, yet its political and institutional architecture prevents this knowledge from becoming understanding or governance. Unless Antarctic science evolves, the 2048 review of the Madrid Protocol may arrive without the legitimacy, data or governance capacity required to confront debates over mineral exploitation and resource governance. We therefore argue that long‐term ecological research must be treated as an institutional obligation rather than a discretionary pursuit of scientific excellence and that Antarctic research infrastructure should be embedded in interoperable observatories more directly linked to existing international coordination mechanisms within the Antarctic Treaty System. Transforming Antarctic science from fragmented observation to coordinated foresight is not just essential for the continent's protection, but for testing the very possibility of collective planetary governance under accelerating change. Read the free Plain Language Summary for this article on the Journal blog.

Highly pathogenic avian influenza of subtype H5N1 (HPAIV H5N1) reached Antarctica in late 2023/2024 breeding season, but the host ecology and movement processes shaping its incursion and spread remain poorly resolved. We investigated these mechanisms by integrating viral genomics, multi-season serology, and seabird movement data at King George Island (Fildes Peninsula, South Shetland Islands), a likely gateway between South America and the Antarctic Peninsula. Across three breeding seasons (2022/23–2024/25), we collected swabs and blood serum from key scavenging and predatory seabirds (Brown skua, South Polar skua, Southern Giant petrel) and paired these data with light-level geolocator tracks (10–16 full annual tracks per species) and breeding-season GPS tracks (10–20 individuals per species). Phylogenetic analyses including three newly generated HPAIV H5N1 genomes from infected Brown skuas placed these viruses within the South Georgia–Antarctic lineage, consistent with introduction via South Georgia followed by onward spread within the region. Longitudinal serology revealed a rapid increase in cumulative exposure in scavenging species, with antibodies against influenza A virus’ nucleoprotein and hemagglutinin subtype H5 rising to high levels by 2024/25 in Brown skuas (52.2%) and Southern Giant petrels (62.5%), but remaining markedly lower in South Polar skuas (12.5%), consistent with their more pelagic and less scavenging foraging behaviour. Tracking showed that migratory connectivity was greatest during the non-breeding period but contracted rapidly during colony return and early breeding. In contrast, network simulations parameterized by high-percentile breeding-season foraging distances indicated strong peninsula-wide connectivity and non-zero potential links toward South Georgia and other sub-Antarctic stepping-stones. Together, these results provide a mechanistic, host-based framework suggesting that HPAIV H5N1 likely reached Antarctica through the South Georgia pathway, but that its regional spread was shaped primarily by foraging ecology and breeding-season movement networks rather than by long-distance migration.

The giant otter (Pteronura brasiliensis) is a charismatic, South American, social carnivore, and the largest otter species in the world. Historically, giant otters were almost extirpated due to the wildlife skin trade and are currently considered as Endangered. Using the Range Wide Priority Setting methodology, we (a group of 33 giant otter experts) updated the species’ historical range (9,021,590 km2), modelled an adjusted and more conservative aquatic historical range of 2,813,539 km2, systematized 5,593 giant otter distribution points across the range, and identified geographic areas for which there was expert knowledge (63%), including areas where giant otters no longer occur (19%), and geographic areas where giant otter presence is uncertain due to a lack of expert knowledge (37%). To prioritize conservation actions into the future and identify existing giant otter population strongholds, we used expert knowledge to identify 22 of the most important areas for the conservation of the species (i.e., Giant Otter Priority Conservation Units [GOPCUs]) that cover 29% of the historical range, and range in size from 1,367 km2 to 829,152 km2. In general, GOPCUs were relatively large and approximately 35% of the total GOPCU area is already designated as protected areas. Using the Range Wide Priority Setting results, we make a series of recommendations towards the long-term conservation of this iconic aquatic species.

Changes in prey availability can lead to mismatches between consumers and resources, decreasing the fitness of consumers, especially during periods of high energy demand such as reproduction. We investigated interseasonal variation in the foraging behaviour of chick-rearing Adelie penguins, Pygoscelis adeliae, in a declining colony in the West Antarctic Peninsula to assess the impact of changes in prey abundance. Specifically, we analysed how these changes affect the energetic cost of males and females during the breeding season. Using information from foraging trips, diet, body condition and daily energy expenditure of 38 Adelie penguins breeding in Ardley Island, King George Island, in 2019/2020 and 2021/ 2022, we found that during low food availability conditions, penguins were forced to increase their foraging effort and their body mass was lower. Specifically, females extended their foraging trips, resulting in 40% higher energy expenditure compared to a year with high prey availability. We observed no significant changes in physiological condition, breeding success or trophic niche. The lower fat reserves and higher energy expenditure of females during the breeding season with low food availability may render them more vulnerable to the challenging conditions of the winter season, with potential negative consequences on population trends. (c) 2025 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Understanding how marine predators structure and adjust their foraging in response to prey field characteristics is a longstanding objective in marine ecology. This is particularly challenging in Southern Ocean ecosystems, where logistical and financial constraints hinder assessment of predator foraging and prey field information at relevant spatial and temporal scales. Here, we examine how Adelie penguins, Pygoscelis adeliae, a key Southern Ocean indicator species, perform and organize their foraging behaviour during two contrasting years of krill (Euphausia superba) abundance. Using multiyear krill acoustic data from King George Island in the West Antarctic Peninsula (WAP), we assess broad seasonal conditions in krill availability. We also analyse a suite of penguin biologging data (spatial location, dive and accelerometry-derived activities) during the same period to identify broad behavioural differences in their bout-diving activity, a classical measure of the temporal organization of foraging in diving predators. During years of high krill abundance and availability, penguins performed shorter dive bouts (consisting of shallower and shorter-duration dives), which were more concentrated in time and space. Despite these differences in bout structure, prey capture attempts occurred at the same rate within bouts. These findings challenge traditional interpretations assuming that increased bout durations (and related proxies of prey capture effort) signal increased krill patch abundance and profitability. Although additional data are required to understand the full scope of penguin bout diving and krill prey field associations, our work improves understanding of penguin behavioural variation and provides insights into how foraging behaviours could potentially be used to interpret krill availability at predator- and management-relevant scales. (c) 2025 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

BackgroundThe Antarctic environment is susceptible to the introduction of non-native species due to its unique ecosystem, which has evolved under geographical isolation and extreme climatic conditions over an extended period. The recent introduction of the non-native winter crane fly, Trichocera maculipennis, to maritime Antarctica may pose a potential threat to the Antarctic ecosystem. In this study, we evaluated the possibility of the mechanical transmission of viruses by T. maculipennis.MethodsWe assessed the potential for the mechanical transmission of viruses using next-generation sequencing (NGS), quantitative PCR (qPCR), and virus isolation methods from T. maculipennis (Tm)-related samples (Tm body-wash fluid and Tm body-ground samples) collected from habitats and sewage treatment facilities located at three research stations in Antarctica.ResultsVirome analysis detected the genomic fragments of human adenovirus (AdV) and human endogenous retrovirus (HERV) in Tm-related samples. These viruses are commonly found in human feces. In addition, plant viruses, such as pepper mild mottle virus (PMMoV) and cucumber green mottle mosaic virus (CGMMV), both known indicators of enteric viruses, were identified in all Tm-related samples, likely originating from wastewater. However, the low quantities of AdV and HERV genomes detected in Tm-related samples through qPCR, coupled with the non-viability of AdV in virus isolation tests, indicate that T. maculipennis has limited potential for mechanical transmission under the conditions in the studies.ConclusionsOur study represents the first evaluation of the potential risk of non-native species serving as vectors for viral pathogens in Antarctica. Although the viruses detected were in relatively low quantities and non-viable, this study highlights the importance of further evaluating the risks associated with non-native species, particularly as the likelihood of their introduction increases to Antarctica due to climate change and increased human activity.

The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a disease among the main causes of amphibian declines worldwide. However, Bd studies on Neotropical amphibians from temperate areas are scarce. We present a comprehensive survey of Bd in Uruguay, in temperate central eastern South America, carried out between 2006 and 2014. Skin swabs of 535 specimens of 21 native and exotic frogs were tested by PCR. We used individual-level data to examine the relationship between infection, climatic variables, and their effects on body condition and the number of prey items found in stomach contents. Infection was widespread in free-ranging anurans with an overall prevalence of 41.9%, detected in 15 native species, wild American bullfrogs Aquarana catesbeiana, and captive specimens of Ceratophrys ornata and Xenopus laevis. Three haplotypes of the Bd ITS region were identified in native amphibians, all belonging to the global panzootic lineage (BdGPL), of which only one was present in exotic hosts. Despite high infection frequencies in different anurans, we found no evidence of morbidity or mortality attributable to chytridiomycosis, and we observed no discernible impact on body condition or consumed prey. Climatic conditions at the time of our surveys suggested that the chance of infection is associated with monthly mean temperature, mean humidity, and total precipitation. Temperatures below 21°C combined with moderate humidity and pronounced rainfall may increase the likelihood of infection. Multiple haplotypes of BdGPL combined with high frequencies of infection suggest an enzootic pattern in native species, underscoring the need for continued monitoring.

In the context of the looming biodiversity crisis, adding patches of habitat has been proposed as a restoration strategy in several ecosystems. However, these interventions rarely mimic the conditions of the natural habitats precisely. Consequently, not all species equally benefit from the restored habitat, fostering a difference in species fitness that could generate an imbalance in the equalizing and stabilizing mechanisms that enable species coexistence, leading to competitive exclusion. Using a metapopulation model, we explore how the introduction of habitat patches with biased fitness advantages affects species coexistence. We show that while adding habitat patches generally increases species occupancy, suboptimal patches can favor one species, disrupting the stabilizing and equalizing mechanisms that enable coexistence, leading to competitive exclusion. This impact on the coexistence regime is particularly pronounced in species with high niche overlap and high colonization-extinction ratios. Our results highlight the double-edged sword effect of suboptimal restoration, revealing potential unintended consequences that could exacerbate biodiversity loss. On the other hand, restoration favoring endangered species is also identified as a conservation tool. The present study advances in the mechanistic comprehension of habitat restoration, a necessary endeavor in the face of the challenges posed by global change. ### Competing Interest Statement The authors have declared no competing interest.

Anthropogenic noise is an inevitable by-product of human activities. However, the potential effects of human noise on terrestrial Antarctica’s ecosystems have been understudied. Documented impacts encompass stress, alterations in behavioural patterns, auditory masking, and, in severe instances, mortality. This Perspective note aims to call attention to human-generated noise as potential sources of impact on Antarctic wildlife and to highlight the potential of soundscape analysis as a flexible, cost-effective tool for environmental monitoring across Antarctica, complementing other non-invasive approaches. Acoustic monitoring in terrestrial environments has been extensively used in different parts of the world to assess biodiversity, monitor populations’ status and trends, and identify and monitor sources of anthropogenic disturbance. Technological advances in passive acoustic monitoring allow for the gathering of detailed information with little need of human attention, and powerful processing tools and algorithms enable researchers to analyse large collections of audio data. Cold climates limit battery-operated instruments, but solar panels in Antarctic summer trials revealed over 100 days of unattended operation, which is promising for the incorporation of acoustic monitoring in Antarctica’s environmental management toolbox.

The current highly pathogenic avian influenza H5N1 panzootic is having substantial impacts on wild birds and marine mammals. Following major and widespread outbreaks in South America, an incursion to Antarctica occurred late in the austral summer of 2023/2024 and was confined to the region of the Antarctic Peninsula. To infer potential underlying processes, we compiled H5N1 surveillance data from Antarctica and sub-Antarctic Islands prior to the first confirmed cases.

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation.

Due to its persistence and potential ecological and health impacts, mercury (Hg) is a global pollutant of major concern that may reach high concentrations even in remote polar oceans. In contrast to the Arctic Ocean, studies documenting Hg contamination in the Southern Ocean are spatially restricted and large-scale monitoring is needed. Here, we present the first circumpolar assessment of Hg contamination in Antarctic marine ecosystems. Specifically, the Adélie penguin (Pygoscelis adeliae) was used as a bioindicator species, to examine regional variation across 24 colonies distributed across the entire Antarctic continent. Mercury was measured on body feathers collected from both adults (n = 485) and chicks (n = 48) between 2005 and 2021. Because penguins’ diet represents the dominant source of Hg, feather δ13C and δ15N values were measured as proxies of feeding habitat and trophic position. As expected, chicks had lower Hg concentrations (mean ± SD: 0.22 ± 0.08 μg·g‒1) than adults (0.49 ± 0.23 μg·g‒1), likely because of their shorter bioaccumulation period. In adults, spatial variation in feather Hg concentrations was driven by both trophic ecology and colony location. The highest Hg concentrations were observed in the Ross Sea, possibly because of a higher consumption of fish in the diet compared to other sites (krill-dominated diet). Such large-scale assessments are critical to assess the effectiveness of the Minamata Convention on Mercury. Owing to their circumpolar distribution and their ecological role in Antarctic marine ecosystems, Adélie penguins could be valuable bioindicators for tracking spatial and temporal trends of Hg across Antarctic waters in the future.