The frequency of extreme weather events, including heat waves, is increasing with climate change. The thermoregulatory demands resulting from hotter weather can have catastrophic impacts on animals, leading to mass mortalities. Although less dramatic, animals also experience physiological costs below, but approaching, critical temperature thresholds. These costs may be particularly constraining during reproduction, when parents must balance thermoregulation against breeding activities. Such challenges should be acute among seabirds, which often nest in locations exposed to high solar radiation and predation risk. The globally endangered bank cormorant Phalacrocorax neglectus breeds in southern Africa in the winter, giving little scope for poleward or phenological shifts in the face of increasing temperatures. Physiological studies of endangered species sensitive to human disturbance, like the bank cormorant, are challenging, because individuals cannot be captured for experimental research. Using a novel, non-invasive, videographic approach, we investigated the thermoregulatory responses of this seabird across a range of environmental temperatures at three nesting colonies. The time birds spent gular fluttering, a behaviour enhancing evaporative heat loss, increased with temperature. Crouching or standing birds spent considerably less time gular fluttering than birds sitting on nests (ca 30% less at 22°C), showing that postural adjustments mediate exposure to heat stress and enhance water conservation. Crouching or standing, however, increases the vulnerability of eggs and chicks to suboptimal temperatures and/or expose nest contents to predation, suggesting that parents may trade-off thermoregulatory demands against offspring survival. We modelled thermoregulatory responses under future climate scenarios and found that nest-bound bank cormorants will gular flutter almost continuously for several hours a day by 2100. The associated increase in water loss may lead to dehydration, forcing birds to prioritize survival over breeding, a trade-off that would ultimately deteriorate the conservation status of this species.

1. An increasing number of species are facing unprecedented levels of threat to their long-term survival due to the direct and indirect impacts of climate change.Key opportunities for science to inform wildlife management are linked to increasing our understanding of how changes in climatic conditions will impact species, as well as whether, and how, managers may facilitate species' ability to adapt to change. However, information on species' climate change vulnerability and the effectiveness of potential conservation actions are not yet strategically collected or collated; this disconnect between threat level, ecological research and conservation practice is reducing the opportunities to guide decisionmaking, ultimately hindering conservation outcomes.2. To demonstrate this point, we explore how existing knowledge can be brought together in a pressure-state-response framework that connects climate change ecology, conservation evidence assessments and management. Seabirds in Western Europe are used as a case study, as they are well-researched and vulnerable to climate change. Using a combination of literature reviews and surveys, we identify the main threats posed to seabirds in the region by climate change, as well as existing conservation actions that could be applied to lessen the impacts of each of these threats. 3. Our results show that 29% of the types of actions considered for reducing the impacts of climate change on seabirds are either associated with conflicting evidence or lack sufficient information to make robust conclusions about their | 1179

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How to best track species as they rapidly alter their distributions in response to climate change has become a key scientific priority. Information on species distributions is derived from biological records, which tend to be primarily sourced from traditional recording schemes, but increasingly also by citizen science initiatives and social media platforms, with biological recording having become more accessible to the general public. To date, however, our understanding of the respective potential of social media and citizen science to complement the information gathered by traditional recording schemes remains limited, particularly when it comes to tracking species on the move with climate change. To address this gap, we investigated how species occurrence observations vary between different sources and to what extent traditional, citizen science, and social media records are complementary, using the Banded Demoiselle ( Calopteryx splendens ) in Britain as a case study. Banded Demoiselle occurrences were extracted from citizen science initiatives (iRecord and iNaturalist) and social media platforms (Facebook, Flickr, and Twitter), and compared with traditional records primarily sourced from the British Dragonfly Society. Our results showed that species presence maps differ between record types, with 61% of the citizen science, 58% of the traditional, and 49% of the social media observations being unique to that data type. Banded Demoiselle habitat suitability maps differed most according to traditional and social media projections, with traditional and citizen science being the most consistent. We conclude that (i) social media records provide insights into the Banded Demoiselle distribution and habitat preference that are different from, and complementary to, the insights gathered from traditional recording schemes and citizen science initiatives; (ii) predicted habitat suitability maps that ignore information from social media records can substantially underestimate (by over 3500 km 2 in the case of the Banded Demoiselle) potential suitable habitat availability.

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With key information linked to thematic maps, this section evaluates the climate change vulnerability of ten species of ducks and phalaropes (Anatidae and Scolopacidae) – Long-tailed Duck, Harlequin Duck, Velvet Scoter, Common Scoter, Red-breasted Merganser, Red Phalarope, Red-necked Phalarope, Steller’s Eider, Common Eider, and King Eider – in the North-East Atlantic. The assessments for every species cover three categories each: the exposure, or the magnitude in percentage and the characteristics of climate change; the sensitivity, or how much and by which climatic events the species are affected, depending on their biological features; the adaptive capacity, or the potential of species to respond to climate change. Assessments of local conservation actions that can be implemented to reduce climate change impacts are listed here in readily consultable tables. This section focuses on the effectiveness of interventions against increasing mammal predation that threatens ducks and phalaropes. Criteria of relevance, strength, and transparency measure the effectiveness of the actions.

As this is evidence-based guidance, appendix 1 provides references and further details to the first section of each bird species examined so far – auks, ducks and phalaropes, gannets and cormorants, gulls, loons/divers and grebes, petrels and shearwaters, skuas, and terns – for each of the three criteria for assessing climate change impacts: exposure, sensitivity, and adaptive capacity. This appendix is meant for those who wish to examine the primary sources or find additional reading. Appendix 2: This appendix provides access to two searchable folders, which include the accompanying methodology and references to the second section of each species – the potential actions in response to climate change. The “Methodology” folder contains information on how the species assessments and the conservation actions were chosen and scored. The “References” folder contains a complete list of all studies used in this guide. The studies documenting the effectiveness of actions on seabirds have been used as the primary evidence base for the second section of each species.

This introduction outlines the content, the language, and the structure of the present volume, a widely referenced guidance for anyone who wishes to quantitatively assess climate change threats to seabirds in the North-East Atlantic. The book has a bipartite structure for each seabird species examined – auks, ducks and phalaropes, gannets and cormorants, gulls, loons/divers and grebes, petrels and shearwaters, skuas, and terns. The first section reviews the vulnerability of each seabird species and their habitats to climate change. The second section lists and estimates the effectiveness of local preventive actions to limit the impacts of climate change through specific criteria. Complementary appendixes contain additional information on sources, references and the methodology used by the contributors to this volume.