Seabirds are among the most threatened vertebrates, under pressure from fisheries bycatch, climate change, overfishing, and human disturbance. In France, demographic studies have highlighted adult survival as a key factor in population trends, which calls for large-scale marine conservation efforts. In this context, the Natura 2000 policy requires the designation of Special Protection Areas (SPAs) to protect seabirds under the Birds Directive. To assess the completeness of the French marine SPA network, data from aerial, boat, and coastal surveys, as well as tracking devices and distribution models, were collected for 57 seabird taxa. This data collection allowed the EU minimum criteria for a coherent SPA network to be spatially implemented, and the most ecologically valuable areas for seabirds around metropolitan France to be identified and prioritised, and overlaid with the current French SPA network and Marine Important Bird Areas (mIBAs) to identify potential inconsistencies. This analysis revealed seabird hotspots outside the existing ecological network, confirming some insufficiencies for coherent seabird conservation. Although data dependent, this analysis highlighted the limitations of using global proportion coverage to assess network coherence when coverage of biodiversity and abundance hotspots was not achieved. Furthermore, these results summarised the main target areas for policy makers to effectively improve seabird conservation around metropolitan France. In a context of increasing demands for marine spatial planning, improvements in this knowledge, the SPA network and conservation actions are required.
High pathogenicity avian influenza virus (HPAIV) caused the worst seabird mass-mortalities on record in Europe across 2021-2022. The northern gannet ( Morus bassanus ) was one of the most affected species, with tens of thousands of casualties in the northeast Atlantic between April-September 2022. Disease outbreaks can drastically modify the movement ecology of animals and diminish spatial consistency, thereby increasing the potential for disease transmission. To detect potential changes in movement behaviour, we GPS-tracked breeding adults following the initial HPAIV outbreak, at three of the largest gannet breeding colonies where major mortality of adults and chicks occurred (Bass Rock, Scotland, UK; Grassholm, Wales, UK; Rouzic island, Brittany, France). Crucially, GPS-tracked birds remained faithful to their breeding sites and did not prospect other breeding colonies. They performed regular foraging trips at sea, similar to their behaviour before the outbreak. Gannet foraging effort was nonetheless lower than in 2019, thus surviving birds may have benefited from reduced intra- and interspecific food competition. Breeding colony fidelity of adult northern gannets following HPAIV mass-mortalities suggests limited long-term capacity to virus spread, which may contrast with the behaviour of adults during the disease outbreak, or with that of younger individuals.
Plastic pollution is distributed patchily around the world's oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species.
IntroductionIn Antarctica, there is growing concern about the potential effect of anthropogenic activities (i.e., tourism, research) on wildlife, especially since human activities are developing at an unprecedented rate. Although guidelines exist to mitigate negative impacts, fundamental data are currently lacking to reliably assess impacts. Physiological tools, such as circulating corticosterone levels, appear promising to assess the potential impact of human disturbance on Antarctic vertebrates.MethodsIn this study, we compared the body condition, and the physiological sensitivity to stress (i.e., basal and stress-induced corticosterone level) of adult and chick Adélie penguins between a disturbed and an undisturbed area (i.e., 2 colonies located in the middle of a research station exposed to intense human activities and 2 colonies located on protected islands with minimal human disturbance).ResultsWe did not find any significant impact of human activities on body condition and corticosterone levels in adults (incubating adults, brooding adults). In chicks, there were significant inter-colony variations in stress-induced corticosterone levels. Specifically, the chicks from the disturbed colonies tended to have higher stress-induced corticosterone levels than the chicks from the protected areas although this difference between areas was not significant. In addition, and independently of human disturbance we also found significant differences in adult body condition, and chick corticosterone level between colonies.DiscussionOverall, our study suggests that this species is not dramatically impacted by human activities, at least when humans and penguins have cohabited for several decades. Our results support therefore the idea that this species is likely to be tolerant to human disturbance and this corroborates with the persistence of Adélie penguin colonies in the middle of the research station. However, our results also suggest that chicks might be more sensitive to human disturbance than adults and might therefore potentially suffer from human disturbance. Our study also suggests that specific individual and environmental variables outweigh the potential minor impact of human disturbance on these variables. Combining corticosterone with complementary stress-related physiological markers, such as heart rate, may strengthen further studies examining whether human disturbance may have subtle detrimental impacts on individuals.
Many animals migrate after reproduction to respond to seasonal environmental changes. Environmental conditions experienced on non-breeding sites can have carryover effects on fitness. Exposure to harmful chemicals can vary widely between breeding and non-breeding grounds, but its carryover effects are poorly studied. Mercury (Hg) contamination is a major concern in the Arctic. Here, we quantified winter Hg contamination and its carryover effects in the most abundant Arctic seabird, the little auk Alle alle. Winter Hg contamination of birds from an East Greenland population was inferred from head feather concentrations. Birds tracked with Global Location Sensors (GLS, N = 28 of the total 92) spent the winter in western and central North Atlantic waters and had increasing head feather Hg concentrations with increasing longitude (i.e., eastward). This spatial pattern was not predicted by environmental variables such as bathymetry, sea-surface temperature or productivity, and needs further investigation. Hg concentrations in head feathers and blood were strongly correlated, suggesting a carryover effect of adult winter contamination on the consequent summer concentrations. Head feather Hg concentrations had no clear association with telomere length, a robust fitness indicator. In contrast, carryover negative effects were detected on chick health, as parental Hg contamination in winter was associated with decreasing growth rate of chicks in summer. Head feather Hg concentrations of females were not associated with egg membrane Hg concentrations, or with egg volume. In addition, parental winter Hg contamination was not related to Hg burdens in chicks' body feathers. Therefore, we hypothesise that the association between parental winter Hg exposure and the growth of their chick results from an Hg-related decrease in parental care, and needs further empirical evidence. Our results stress the need of considering parental contamination on non-breeding sites to understand Hg trans-generational effects in migrating seabirds, even at low concentrations.
Effective conservation assessments require detailed information of species' ecological niches during the whole annual cycle. For seabirds, this implies investigating the at-sea distribution and foraging behaviour during both the breeding and non-breeding periods. However, until recently, collecting information about small species has been precluded by the excessive size of the required devices. This lack of knowledge is exacerbated in the case of polytypic genera with species sharing very similar appearance and behaviour, such as the super-abundant prions (Pachyptila spp.). The present study investigates the year-round at-sea distribution and foraging ecology of the fairy prion (Pachyptila turtur) in southeastern Australia. Miniaturized GPS loggers during the breeding season and geolocators (GLS) during the non-breeding period were used over 4 consecutive years (2017-2021), with results that highlight the importance of the continental shelf-edge waters for fairy prions throughout the year. In addition, contrary to previous assumptions, the GLS data revealed an unsuspected post-breeding migration to the waters south of Australia, during which individuals probably undergo a rapid moult of flight feathers. Understanding the at-sea distribution and ecology of prions during the whole annual cycle will be fundamental to their conservation as it can reveal species- or population-specific threats that have been overlooked because of their status as abundant species.
Albatrosses are amongst the most globally-threatened species and fisheries bycatch is one of the major conservation issues worldwide. Among the albatrosses the Amsterdam albatross is listed as one of the most endangered species. Within the current National Plan of Actions framework, the present study outlines the first results of a multi-year survey evaluating juvenile dispersal and immature at sea distribution using geolocation and conservation implications. Here we report the first evidence of an Amsterdam albatross wandering for extensive periods outside the Indian Ocean, in the Pacific Ocean. This unprecedented and novel finding is discussed in terms of overlaps with fisheries and conservations issues. This study brings new insights on movements of vagrant stages of an endangered species, paving the way for refined assessments updates of species vulnerability to ongoing anthropogenic threats while providing basic conservation guidance. This makes it possible to point out the responsibility of the various management bodies both for the high seas regional fisheries management organisations and for exclusive economic zones.
Defining the impact of anthropogenic stressors on Antarctic wildlife is an active aim for investigators. Telomeres represent a promising molecular tool to investigate the fitness of wild populations, as their length may predict longevity and survival. We examined the relationship between telomere length and human exposure in Adélie penguin chicks ( Pygoscelis adeliae ) from East Antarctica. Telomere length was compared between chicks from areas with sustained human activity and on neighboring protected islands with little or no human presence. Adélie penguin chicks from sites exposed to human activity had significantly shorter telomeres than chicks from unexposed sites in nearby protected areas, with exposed chicks having on average 3.5% shorter telomeres than unexposed chicks. While sampling limitations preclude our ability to draw more sweeping conclusions at this time, our analysis nonetheless provides important insights into measures of colony vulnerability. More data are needed both to understand the proximate causes (e.g., stress, feeding events) leading to shorter telomeres in chicks from human exposed areas, as well as the fitness consequences of reduced telomere length. We suggest to further test the use of telomere length analysis as an eco-indicator of stress in wildlife among anthropized sites throughout Antarctica.
Most Procellariform seabirds are pelagic, breed in summer when prey availability peaks, and migrate for winter. They also display a dual foraging strategy (short and long trips) and sex-specific foraging. The Westland petrel Procellaria westlandica , a New Zealand endemic, is one of the rare seabirds breeding in winter. Preliminary findings on this large and sexually dimorphic petrel suggest a foraging behaviour with no evidence of a dual strategy, within a narrow range and with shared areas between sexes. To investigate further this unusual strategy, the present study determined the fine-scale at-sea behaviours (global positioning system and accelerometer data loggers) and trophic niches (stable isotopes in whole blood) of chick-rearing individuals (16 males and 13 females). All individuals foraged on the shelf-slope of the west coast of New Zealand's South Island with short, unimodal trips. Both sexes foraged at similar intensity without temporal, spatial or isotopic niche segregation. These findings suggest the presence of a winter prey resource close to the colony, sufficient to satisfy the nutritional needs of breeding without increasing the foraging effort or intra-specific competition avoidance during winter. Additional data are needed to assess the consistency of foraging niche between the sexes and its reproductive outcomes in view of anticipated environmental changes.
Spatiotemporal dynamics of ecosystems can challenge the pertinence of Marine Protected Area (MPA) planning. Seasonal environmental changes are extreme in polar regions, however MPA planning in East Antarctica relies mostly on species' summer distribution only. Thirteen Adélie penguins were tracked from Ile des Pétrels (Terre Adélie), and their seasonal distribution and behaviour were compared to the proposed “D'Urville Sea-Mertz” MPA. During the phase of high food-demand preceding moult, penguins used mostly (68.4%) this proposed area. However, following autumnal sea ice extension, penguins migrated north-westwards: overall, 73% of their locations were outside the MPA proposal, and this was up to >99% during winter (in July), the season when penguins maximized their dive depth and time (August and September, respectively). This study thus supports the proposal of implementing a “krill no-take zone” policy in this MPA, in line with the pre-moult foraging of these krill predators in this area. Further protection of the year-round habitats of migratory Adélie penguins could be achieved by inter-connecting the East Antarctic MPA proposals along the ice edge during winter, thereby mirroring the ecosystem's seasonal dynamics.
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 614:183-197 (2019) - DOI: https://doi.org/10.3354/meps12910 Foraging ecology of a winter breeder, the Fiordland penguin Timothée A. Poupart1,2,3,*, Susan M. Waugh2, Charles A. Bost3, Akiko Kato3, Colin M. Miskelly2, Karyne M. Rogers4, John P. Y. Arnould1 1School of Life and Environmental Sciences, Faculty of Science & Technology, Deakin University, 221 Burwood Highway, Burwood, VIC 3125, Australia 2Museum of New Zealand, Te Papa Tongarewa, PO Box 467, Wellington 6011, New Zealand 3Centre d’Études Biologiques de Chizé, UMR7372 CNRS/Univ La Rochelle, 79360 Villiers-en-Bois, France 4National Isotope Centre, GNS Science, PO Box 31-312, Lower Hutt 5040, New Zealand *Corresponding author: timothee.poupart@gmail.com ABSTRACT: Breeding in most species is timed to coincide with the greatest availability of food resources to support the increased energetic needs of reproduction. Correspondingly, the majority (76%) of seabird species in temperate and polar regions breed in spring/summer, matching the peak in ocean productivity. The Fiordland penguin Eudyptes pachyrhynchus is one of only 34 seabird species worldwide that have part of their breeding cycle during the winter, and its chicks fledge when the eggs of congeneric Eudyptes species in the same region are only starting to hatch. Little is known of the foraging ecology of this species and the factors that may influence its timing of breeding. In the present study, the foraging behaviour of breeding individuals from Taumaka/Open Bay Island, New Zealand, was investigated using GPS, dive recorder and tri-axis accelerometer data loggers. In total, 35 individuals (4 males, 31 females) were tracked at sea, revealing extensive use of continental shelf slope (200-1000 m) habitat within 42 ± 5 km of the colony. Individuals foraged mostly during daylight in the epi-pelagic zone (mean modal depth 22 ± 2 m) and prey encounter events occurred in 50% of dives. Blood isotopic signatures suggest a trophic level indicative of squid consumption, supporting previous findings that winter-spawning squid are the most important prey type. The results of the present study suggest that a winter-breeding strategy by seabirds can reflect locally abundant prey resources and suitable conditions at the time for breeding. KEY WORDS: Foraging behaviour · Winter breeding · Bio-logging · Prey encounter · Eudyptes pachyrhynchus · New Zealand Full text in pdf format Supplementary material PreviousNextCite this article as: Poupart TA, Waugh SM, Bost CA, Kato A, Miskelly CM, Rogers KM, Arnould JPY (2019) Foraging ecology of a winter breeder, the Fiordland penguin. Mar Ecol Prog Ser 614:183-197. https://doi.org/10.3354/meps12910 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 614. Online publication date: April 04, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.
Parental care can lead to a conflict of interest between parents and offspring. For central place foragers, conflict is expected to be particularly intensive in species that feed on relatively inaccessible, distant food resources. Some pelagic seabirds use distinct foraging strategies when provisioning young versus self-feeding: short trips near the colony versus long trips far away. Limited empirical evidence shows that the strategy used by parents depends on their own state and that of their young, suggesting that dynamic optimization may help reduce conflict. Tests of this hypothesis, however, are scarce. Using a combination of GPS tracking and nest monitoring, we examined whether foraging strategy choice by Manx shear-waters, Puffinus puffinus, is explained by the body condition of parents and offspring before trip departure, and whether choice affects condition upon return. When chick body condition was poor prior to departure, subsequent foraging trips by adults were significantly shorter and chick condition upon return improved. When chick condition was good prior to departure, the reverse happened. There was no evidence that adult condition affected subsequent trip choice, but adults returning from slow, long-duration trips were in comparatively better condition. Thus, although the trips that were good for offspring were different to those that were favourable for adults, trip choice was only dependent on chick condition, which may explain why there was no evidence for a trade-off between adult and chick condition during individual trips. Our results suggest that spatiotemporal variation in foraging strategies is driven by the conflicting needs of parents and offspring, but that the parents can reduce the conflict, resulting in no detectable trade-off under these conditions. This link between parental care and space use is likely to be widespread in central place foragers but remains largely unexplored in most systems. (C) 2019 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.
Predators generally time their reproductive events to match the peak in prey resource availability in order to sustain the elevated energy requirement of offspring provisioning. Consequently, most temperate/polar seabirds breed in spring/summer, including the majority of small albatross species that have short breeding cycles. In contrast, the southern Buller's albatross Thalassarche bulleri bulleri has a delayed breeding schedule, with chick-rearing extending throughout the entire austral winter. In the present study, the fine-scale at-sea movements and trophic niche of chick-rearing southern Buller's albatross were determined at Hautere/Solander Island (New Zealand, 46 degrees 35' S, 166 degrees 54' E) during the 2016 and 2017 chick-rearing periods to investigate the winter foraging strategy used during this nominally challenging period. The tracks recorded by 15 males (n = 43) and 11 females (n = 21) revealed that foraging behaviour accounted for only a small proportion of time at sea, primarily influenced by the time of day. Foraging occurred mainly in the neritic waters of New Zealand's South Island shelf, with individuals under-taking consistent short trips (<= 230 km from the colony) or alternating short and long trips up to 1500 km from the colony. Fine-scale tracking data revealed that males spent more time foraging, during shorter trips than females. Their isotopic niches were small, with overlap between sexes, but with males having higher delta N-15 values than females. Time spent foraging was influenced by both static and dynamic oceanographic variables. These findings suggest that southern Buller's albatross foraging behaviour, despite having to sustain chick provisioning in winter, is similar to that of summer-breeding congeners.
Environmental and anthropogenic influences in the marine environment are primary drivers of behavior and demographic outcomes for marine birds. We examined factors influencing the foraging patterns of the Westland Petrel (Procellaria westlandica), a highly threatened, endemic petrel that inhabits subtropical water masses primarily in the Tasman Sea, with a poorly known at-sea distribution. Risk assessments place the species at moderate risk of population impacts from fisheries-related mortality. Studies in the 1990s indicated that trawl fisheries would have an important influence on the Westland Petrel's foraging behavior. We investigated the influence of climatic conditions, marine productivity, bathymetry, the core fishery zone, concurrent fishing activity, light conditions, sex, and breeding stage on Westland Petrel foraging patterns. We analyzed the stable isotopes of carbon and nitrogen from blood sampled during the incubation period and examined changes in isotopic niche width over a 6-yr period. We found that the Westland Petrel's foraging zone varied only slightly between years and that the location of intensively used areas was strongly influenced by bathymetric slope and latitude, and negatively influenced by chlorophyll-a. The core fishery zone had a secondary influence, suggesting that these petrels co-occur with fisheries, but are not dependent on waste for food. Trophic niche width was significantly wider during strong El Nino conditions, indicating that food type, rather than location, was most affected by climatic variation. Consistent use of one marine area across varying times and conditions increases the risk of adverse effects of climate or human-induced impacts on the species. However, marine spatial management tools become viable in these conditions. Further, with rapid increases in sea surface temperatures and extreme values recorded in the region in recent periods, changes to fisheries zones and distributions of natural prey of the species are likely to occur and may change the population's sustainability.
In the d'Urville Sea in East Antarctica, a population of roughly 20,000 pairs of Adelie penguins of Iles des Petrels (Terre Addle) has experienced two massive breeding failures, with no chick surviving the 2013-14 and 2016-17 breeding seasons. In both seasons the extent of sea ice in front of the colony persisted throughout the breeding cycle of the birds. The timing of sea-ice recession differed greatly between seasons and the absence of polynya in a crucial phase of the cycle were paramount in driving these failures. The change in the icescape in front of Ile des Petrels following the calving of the Mertz glacier in 2010, together with increase in precipitations and changes in sea-ice firmness explain this situation and are discussed in the present manuscript. To prevent additional future impacts on this colony, like competition with fisheries for instance, we strongly support a scientific research zone in the d'Urville Sea- Mertz area, one of the three zones of proposed Marine Protected Area in East Antarctica to the Commission for the Conservation of Antarctic Marine Living Resources.
Jellyfish and other pelagic gelatinous organisms (“gelata”) are increasingly perceived as an important component of marine food webs but remain poorly understood. Their importance as prey in the oceans is extremely difficult to quantify due in part to methodological challenges in verifying predation on gelatinous structures. Miniaturized animal‐borne video data loggers now enable feeding events to be monitored from a predator's perspective. We gathered a substantial video dataset (over 350 hours of exploitable footage) from 106 individuals spanning four species of non‐gelatinous‐specialist predators (penguins), across regions of the southern oceans (areas south of 30°S). We documented nearly 200 cases of targeted attacks on carnivorous gelata by all four species, at all seven studied localities. Our findings emphasize that gelatinous organisms actually represent a widespread but currently under‐represented trophic link across the southern oceans, even for endothermic predators, which have high energetic demands. The use of modern technological tools, such as animal‐borne video data loggers, will help to correctly identify the ecological niche of gelata.
Albatrosses are flexible and adaptable predators, relying on live prey as well as carrion. Use of predictable food sources and reliance on human-produced resources are well-known trait in long-range feeders like albatrosses and petrels. Breeding Buller's albatrosses studied at Solander I. (Hautere), New Zealand fed their chicks the remains of sooty shearwater juveniles (tītī in Māori), which are harvested from nearby muttonbirding sites. Evidence of this food type was found at over 10% of nests examined, and 17-40% birds that were fitted with GPS loggers visited muttonbirding sites in this and previous studies. Muttonbirding is a traditional practice that has continued for centuries, with up to 120 tonnes of offal discharged to the sea annually during the present day harvest. It coincides with the energetically-demanding early chick period for the albatrosses. Our finding suggests that the offal may be an important, but overlooked element in the albatross diet. As an important supplementary food for the albatrosses it is likely to have contributed to the 3% per annum growth of their populations since the first comprehensive population surveys in 1969.
The little penguin Eudyptula minor is primarily an inshore forager with its range generally limited to c. 30km of breeding sites during the nesting period. However, exceptions with greater foraging distances have been recorded in Australia. To investigate the foraging range plasticity in New Zealand we used GPS tracks gathered on 68 individuals in three regions of central New Zealand between 2011 and 2016. Foraging patterns varied between sites and between years. Tracks revealed that penguins can rely on distant foraging areas while incubating, with nesting birds travelling up to 214km to feed. Isotope analyses of blood samples showed that this distant food across deep waters (0-200m) is likely to be squid dominated. During the chick rearing period, birds undertook a diet shift to a higher trophic level while foraging closer to their colony, and possibly near river plumes. These findings highlight the need to consider the little penguins' large potential foraging ranges when managing threats and changes to the environment.
Concern of pelagic gelatinous organisms taking over perturbed marine ecosystems has led to a recent increase in research into this group. However, the significance of this group as prey remains challenging to assess, and hence, gelatinous consumers are often depicted incorrectly as dead ends of pelagic food webs. In the Southern Ocean, where a shift in trophic webs may favour gelatinous animals, we video-monitored prey intake of a key predator. Twenty-eight chick-rearing Adélie penguins Pygoscelis adeliae from Dumont d’Urville station (66°40′S, 140°01′E) were instrumented with miniaturized video loggers in 2014–2015. Among other items (krill, fish), 101 gelatinous organisms (n = 79 jellyfish, 6 salps and 16 unidentified) were observed on 13 of 21 exploitable video footages (total: 59 h). Importantly, 65.3 % of gelatinous organisms were attacked, but among them salps were not attacked. Attacks on jellyfish were significantly associated with the visible presence of the jellyfish’s gonad. Jellyfish were encountered at an average depth of 26.2 ± 10.4 m, significantly shallower than krill. Attacks occurred mostly during bottom, but also descent or ascent dive phases. Concomitant GPS location for four birds revealed that attacks on jellyfish occurred above the shelf, 35 km north from the colony, where sea ice concentration reached 88 %. These results indicate that Adélie penguins occasionally feed on jellyfish, even though other prey types are also available. Refining our perception of scyphozoans’ niche may thus help anticipate the functional response of the food webs to the extensive changes witnessed in the Antarctic environment.