7 research outputs found

    Manx shearwater (Puffinus puffinus) rafting behaviour revealed by GPS tracking and behavioural observations

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    Before visiting or leaving their remote island colonies, seabirds often engage in a behaviour termed ‘rafting’, where birds sit, often in groups, on the water close to the colony. Despite rafting being a widespread behaviour across many seabird taxa, the functional significance of rafting remains unknown. Here we combine global positioning system (GPS) tracks, observational and wind condition data to investigate correlates of rafting behaviour in Manx shearwaters (Puffinus puffinus) at a large colony on Skomer Island, Wales. We test (1) the influence of wind direction on rafting location and (2) whether raft size changes with respect to wind speed. Our approach further allows us to describe day-night trends in (3) raft distance from shore through time; (4) the number of birds present in the nearshore waters through time; and (5) spatial patterns of Manx shearwater rafts in marine waters adjacent to the breeding colony. We find no evidence that wind direction, for our study period, influences Manx shearwater rafting location, yet raft size marginally increases on windier days. We further find rafting birds closer to the shore at night than during the day. Thus, before sunset, birds form a “halo” around Skomer Island, but this halo disappears during the night as more individuals return from foraging trips and raft nearer the colony on Skomer Island. The halo pattern reforms before sunrise as rafts move away from land and birds leave for foraging. Our results suggest that wind conditions may not be as ecologically significant for rafting locations as previously suspected, but rafting behaviour may be especially important for avoiding predators and cleaning feathers

    Biological traits of seabirds predict extinction risk and vulnerability to anthropogenic threats

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    Aim: Seabirds are heavily threatened by anthropogenic activities, and their conservation status is deteriorating rapidly. Nonetheless, these pressures are unlikely to impact all species uniformly. It remains an open question whether seabirds with similar ecological roles are responding similarly to human pressures. Our aims were as follows: (a) to test whether threatened versus non‐threatened seabirds are separated in trait space; (b) to quantify the similarity of species' roles (redundancy) per IUCN Red List Category; and (c) to identify traits that render species vulnerable to anthropogenic threats. Location: Global. Time period: Contemporary. Major taxa studied: Seabirds. Methods: We compile and impute eight traits that relate to species' vulnerabilities and ecosystem functioning across 341 seabird species. Using these traits, we build a mixed‐data principal component analysis of species' trait space. We quantify trait redundancy using the unique trait combinations (UTCs) approach. Finally, we undertake a similarity of percentages analysis to identify which traits explain the greatest difference between threat groups. Results: We find that seabirds segregate in trait space based on IUCN threat status, indicating that anthropogenic impacts are selectively removing large, long‐lived, pelagic surface feeders with narrow habitat breadths. We also find that threatened species have higher trait redundancy, whereas non‐threatened species have relatively limited redundancy. Finally, we find that species with narrow habitat breadths, fast reproductive speeds and varied diets are more likely to be threatened by habitat‐modifying processes (e.g., pollution and natural system modifications), whereas pelagic specialists with slow reproductive speeds and varied diets are vulnerable to threats that directly impact survival and fecundity (e.g., invasive species and biological resource use) and climate change. Species with no threats are non‐pelagic specialists with invertebrate diets and fast reproductive speeds. Main conclusions: Our results suggest that both threatened and non‐threatened species contribute unique ecological strategies. Consequently, conserving both threat groups, but importantly with contrasting approaches, might avoid potential changes in ecosystem functioning and stability

    Species’ traits and exposure as a future lens for quantifying seabird bycatch vulnerability in global fisheries

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    Fisheries bycatch, the incidental mortality of non-target species, is a global threat to seabirds and a major driver of their declines worldwide. Identifying the most vulnerable species is core to developing sustainable fisheries management strategies that aim to improve conservation outcomes. To advance this goal, we present a preliminary vulnerability framework for the context of bycatch mortality that integrates dimensions of species’ exposure (the extent a species’ range overlaps with fishing activities and the magnitude of activities experienced), sensitivity (a species’ likelihood of bycatch mortality when it interacts with fisheries), and adaptive capacity (the ability for populations to adapt and recover from bycatch mortalities). This allows us to classify species into five vulnerability classes. The framework combines species’ traits and distribution ranges for 341 seabirds, along with a spatially resolved fishing effort dataset. Overall, we find most species have high-vulnerability scores for the sensitivity and adaptive capacity dimensions. By contrast, exposure is more variable across species, and thus the median scores calculated within seabird families is low. We further find 46 species have high exposure to fishing activities, but are not identified as vulnerable to bycatch, whilst 133 species have lower exposure, but are vulnerable to bycatch. The framework has been valuable for revealing patterns between and within the vulnerability dimensions. Further methodological development, additional traits, and greater availability of threat data are required to advance the framework and provide a new lens for quantifying seabird bycatch vulnerability that complements existing efforts, such as the International Union for Conservation of Nature (IUCN) Red List

    Bycatch-threatened seabirds disproportionally contribute to community trait composition across the world

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    Human pressures in the ocean are restructuring biological communities, driving non-random extinctions, and disrupting marine ecosystem functioning. In particular, fisheries bycatch, the incidental mortality of non-target species, is a major threat to seabirds worldwide. Direct bycatch data are often scarce. Instead, leveraging trait-based analyses with fine-scale fisheries data could answer fundamental questions about spatial patterns of bycatch-threatened species and facilitate targeted conservation strategies. Here, we combine a dataset of species' traits and distribution ranges for 361 seabird and sea duck species with spatially resolved fishing effort data for gillnet, longline, trawl, and purse seine gears. First, we quantify geographic patterns of seabird community traits. Second, we describe how community traits could shift under local extinction scenarios in areas where bycatch-threatened seabirds spatially overlap with fishing activities. These objectives allow us to highlight the collective contribution of species currently threatened from bycatch to ecosystem functioning. We reveal distinct spatial variation in the community weighted mean of five seabird traits (body mass, generation length, clutch size, diet guild, and foraging guild) are evident. Moreover, our results show that fisheries bycatch is selectively removing a distinct suite of traits from the community within particular oceanic regions. Specifically, fisheries bycatch is threatening species with larger body masses, slower reproductive speeds (smaller clutch sizes and longer generation lengths), and specialised diet and foraging guilds. The spatial non-uniformity of the community trait shifts suggests that within specific marine regions, communities have limited redundancy and therefore may have less insurance to buffer against declines in ecosystem functioning. Our extinction scenario warns that seabirds currently threatened from fisheries bycatch substantially contribute to community functional composition. Management actions that incorporate species’ traits and fine-scale fisheries datasets as tools for marine spatial planning will add an important dimension when evaluating the success of conservation initiatives

    Global COVID-19 lockdown highlights humans as both threats and custodians of the environment

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    The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus, initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness

    Global COVID-19 lockdown highlights humans as both threats and custodians of the environment

    Get PDF
    The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness
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