Land-use changes are considered one of the main drivers of biodiversity loss. Agricultural intensification, pastoral abandonment, and changes in forest management have led to the homogenisation of landscapes. In particular, the encroachment of grasslands and the densification of forests that are no longer pastured threaten species that require multiple habitats to nest and forage, such as the European Nightjar Caprimulgus europaeus. Whereas previous studies have focused on understanding factors influencing the decrease of nightjars at regional or national scales, here, we aimed to assess fine-scaled habitat selection by nightjars within nesting and foraging sites based on high-resolution GPS tracking data. Vegetation structure and composition were quantified in the field. In the nesting habitat, nightjars prefer open forests with a low percentage of trees and where the ground is not covered by more than 40% of grass and crawling bushes (dwarf bushes such as Juniperus species). In contrast, when foraging, nightjars select open grasslands and biodiversity-friendly managed vineyards, both richly structured, i.e. interspersed or surrounded by other land-use types such as hedges or isolated trees. Both the nesting and foraging habitats are currently threatened, either by the abandonment of forest management, which makes stands denser and more homogeneous, or through agricultural intensification, which reduces land-use diversity. Clear habitat-specific management recommendations and political incentives are needed to simultaneously preserve and/or restore these critical habitats, which are important for nightjars that use complementary resources for nesting and foraging.

Bycatch, the incidental capture of non-target species in fishing gear, has been recognised as the most significant global conservation threat affecting seabird species. Geographically, bycatch rates vary widely, depending on local fishing efforts, environmental features, and seabird community composition. Regional and local research is essential due to the complexity of accurately extrapolating general conclusions regarding the impacts of bycatch. Existing European bycatch research predominantly focuses on northern regions, leaving a significant knowledge gap regarding bycatch in the Mediterranean Sea. This work presents findings of wintering diving seabirds as bycatch of small-scale fisheries in a coastal area of the northern Adriatic Sea, based on data collected between 2021 and 2023. Seabird distribution varied along the depth profile. The bathymetric range between 3 m and 5 m was the most exploited by fishermen. Bycatch of seabirds was confirmed in the study area, with five species recorded, i.e. Black-necked Grebe Podiceps nigricollis, Red-throated Loon Gavia stellata, Black-throated Loon Gavia arctica, Mediterranean Shag Gulosus aristotelis desmarestii, and Great Crested Grebe Podiceps cristatus. Our results suggest that bathymetry likely plays a strong influence on bycatch occurrence. Incidental captures were not widespread but appeared concentrated in the shallowest depths <5 m and the range <2.5 m was identified as particularly susceptible due to the low associated fishing effort and the majority of bycatch events recorded. We estimate that between 46 and 108 birds were incidentally captured during the research period. This study identifies key factors shaping the areas of bycatch vulnerability and risk, proposing a spatial–temporal mitigation framework within Natura 2000 sites and highlighting the value of local stakeholders’ engagement.

Medium to small petrels that mostly nest in burrows or crevices represent a large fraction of the world’s seabirds, yet their population trends are largely unknown. This lack of knowledge, which has implications for conservation planning, results mostly from methodological difficulties and from the approaches that have been used for their monitoring. Here, we present the surveying scheme created to monitor Cory’s Shearwater Calonectris borealis breeding numbers at their largest known colony, Selvagem Grande (Portugal). We defined 60 circular plots at fixed locations on this 2.45 km2 island and counted nests with eggs annually at the end of laying. Results show that the population increased at 1.45% (95% confidence interval [CI]: 0.72–2.01%) per year between 2009 and 2023. We estimate that the current population size is 38,830 pairs (95% quantile CIs = 34,373–43,713). To the best of our knowledge, this study provides the first systematic information (using fully repeatable methods and providing CIs for the estimates) on population trends of Cory’s Shearwaters, one of the most abundant seabirds in the warm temperate and subtropical North Atlantic and one of the most studied petrels globally. Monitoring using the approach detailed here requires two days of work (by 2–3 persons) per year. Our results and simulations indicate that this is a powerful methodology, with narrow confidence limits for estimated trends and an ability to detect small population changes over short time spans. We suggest that more monitoring protocols similar to this one (with necessary site-specific adaptations, particularly for potential colony expansion where suitable habitat exists) should be developed and implemented in a range of colonies with crevice and burrowing nesting petrels to improve our knowledge on the population status of a broad fraction of the world’s seabirds.

Birds are often used as ecological indicators because they are widely distributed across diverse habitats and display distinct behavioural responses to environmental changes. The Endangered Grey Crowned Crane Balearica regulorum is regarded as a flagship species of Africa’s wetland and grassland habitats, both of which are undergoing substantial transformation to alternative land uses. The delayed reproductive strategies and habitat specialisation of this crane species makes them more vulnerable to extinction, but this risk is further compounded by data paucity. We employed traditional and contemporary survey methods to collect breeding metrics to calculate stage transition probabilities (i.e. egg–hatchling, hatchling–juvenile) and to identify possible macro-environmental factors that either promote or hinder their reproductive output in a key agricultural area in KwaZulu-Natal, South Africa. We found that Grey Crowned Cranes have a low hatching rate of 38.4% (95% confidence interval 29.3–48.4%) and show that this low hatching rate is exacerbated under high rainfall intensity. Multivariate analyses and multi-model inference revealed that successful nest-sites were generally associated with larger open water-bodies, greater distances from shore, and increased proximity to secondary roads, buildings, and natural grasslands. Although increased agricultural activities might promote greater foraging opportunities, the overall breeding outcomes of this species were poor in this key agricultural region. Our findings stress the urgent need for further fine-scale data collection and monitoring activities to better inform conservation strategies for this species. We also encourage future studies to focus on aspects affecting Grey Crowned Crane breeding in regions where proximity to human activities is inevitable.

The Eastern population of the Lesser White-fronted Goose (EPLWFG) Anser erythropus is shared between Russia and China. The summer range of the EPLWFG has been recognised as a continuous area extending from the Olenyok River in the west to the Anadyr River in the east and northwards from 64°N. The aim of this study was to provide information on breeding behaviour; nest-sites, nesting habitats, and time of nesting; nesting success; timing of summer movements including moult migration; moult timing, duration, and moulting habitats; site fidelity; and the effect of human presence. To accomplish this, we combined the results from field surveys with GPS/GSM tracking. A total of 30 summer tracks from 19 individual EPLWFG were analysed. We estimated breeding propensity in 93.8% of adult LWFG, and this factor did not seem to depend on breeding success in the previous season. Reproductive success was 13.3% in all nesting attempts. Non-breeders arrived three-week later and departed a week earlier. The EPLWFG are highly mobile during the summer. The core moulting site for the entire EPLWFG was discovered by this study and is located along the lower reaches of the San-Yuryakh and Kyuanekhtyakh rivers flowing towards the Omulyakhskaya Bay of the East Siberian Sea. The EPLWFG flightless period was 24.8 ± 2.8 days. A part of failured EPLWFG (43.7 %) migrated back to its early summer breeding/staging site after having completed moult. The strong site fidelity (100%) of adult birds to both nesting and moulting sites promotes the formation of local breeding populations, which could be considered conservation units if genetic studies support this differentiation. The EPLWFG selects the remotest and least human-accessible area for their remigial moult, and the main site was discovered with the help of tracking.

The global population and status of Snowy Owls Bubo scandiacus are particularly challenging to assess because individuals are irruptive and nomadic, and the breeding range is restricted to the remote circumpolar Arctic tundra. The International Union for Conservation of Nature (IUCN) uplisted the Snowy Owl to “Vulnerable” in 2017 because the suggested population estimates appeared considerably lower than historical estimates, and it recommended actions to clarify the population size, structure, and trends. Here we present a broad review and status assessment, an effort led by the International Snowy Owl Working Group (ISOWG) and researchers from around the world, to estimate population trends and the current global status of the Snowy Owl. We use long-term breeding data, genetic studies, satellite-GPS tracking, and survival estimates to assess current population trends at several monitoring sites in the Arctic and we review the ecology and threats throughout the Snowy Owl range. An assessment of the available data suggests that current estimates of a worldwide population of 14,000–28,000 breeding adults are plausible. Our assessment of population trends at five long-term monitoring sites suggests that breeding populations of Snowy Owls in the Arctic have decreased by more than 30% over the past three generations and the species should continue to be categorised as Vulnerable under the IUCN Red List Criterion A2. We offer research recommendations to improve our understanding of Snowy Owl biology and future population assessments in a changing world.

Amazon parrots stand out as one of the most illegally traded Psittacids in the neotropics. However, the lack of effective tools for determining the geographical origin of confiscated individuals has impeded the development of well-informed release programmes. In this study, we evaluated the efficacy of the cytochrome oxidase subunit I (COI) gene to identify phylogeographical groups and infer the origins of seized individuals across six Amazon parrot species. Through comprehensive genetic and phylogenetic analyses of 140 COI sequences from individuals with documented geographical origin, a genetic reference database was assembled. The most likely origin of 156 seized parrots was inferred by comparing their genotype to this database. Within the Yellow-headed Parrot Amazona ochrocephala species complex, our analyses revealed the presence of seven distinct phylogeographical groups, exposing a notable poaching impact in the Middle Magdalena’s river valley. For the Southern Mealy Amazon A. farinosa, three distinct genetic groups were identified, with seized individuals showing comparable proportions originating from both the Cis- and Trans-Andean regions. Noteworthy genetic differentiation was observed between individuals of Festive Amazon A. festiva from the Caquetá–Amazon Rivers and those from the Meta River, with two seized individuals assigned to the former. The Scaly-naped Amazon A. mercenaria exhibited genetic divergence between individuals from the central Andes and the Sierra Nevada de Santa Marta. In contrast, the Orange-winged Amazon A. amazonica and Red-lored Amazon A. autumnalis did not display significant phylogeographical structure. However, analyses of seized individuals of A. amazonica suggested a potential underestimation of its genetic diversity and structure. This study illustrates the utility of mitochondrial molecular markers in determining the most probable area of origin for confiscated Amazon parrots, aiding in release programmes and enhancing the monitoring of natural populations.

In sub-Saharan Africa, and particularly within Ghana’s savanna ecosystem, scientific studies on the distribution patterns and habitat use of raptors, including vultures, are scarce. Despite global research on vulture abundance and habitat preferences, data from West Africa remain limited. This study examines the abundance of four vulture species, focusing on their seasonal activity, age distribution, and preference for three specific habitats, i.e. woodlands, riparian forests, and grasslands, in the southern part of Mole National Park (MNP), Ghana. We conducted a survey using 39 line transects during both dry and wet seasons to make an inventory of these species. Employing a generalised linear model, we assessed the influence of seasons, age, and habitat types on vulture abundance. Our survey recorded a total of 466 vultures, with Hooded Vulture Necrosyrtes monachus and White-backed Vulture Gyps africanus being the most frequently observed. Vulture numbers were notably higher in riparian and woodland areas than in grasslands, and adults were more prevalent than juveniles across all observed species. The study highlights the need for continuous monitoring and the protection of critical riparian habitats to aid in the conservation of these threatened species within the MNP.

Owing to habitat loss, the entire breeding population of the globally threatened Aquatic Warbler Acrocephalus paludicola, a flagship bird species of fen mires, is now limited to scattered areas in east-central Europe. The breeding biology of the Aquatic Warbler was studied between 2012 and 2015 in calcareous fens dominated by the Cladietum marisci sedge community at the south-western range limit of the species, near Chełm, in south-east Poland. Two nesting peaks were observed during the breeding season, corresponding to first and second breeding attempts. Nest densities were greater during the first- rather than the second-brood period but singing male densities did not differ between the brood periods. Clutch size and post-hatching fledging success were significantly lower during the second-brood period. Total nest fledging success (whether or not a nest fledged at least one young) was 76.6% in 124 nests with known outcomes with an average of 2.7 (± SE 0.2) fledglings per nest. Mayfield probability of nest survival was 56.9% with losses mainly due to predation (55%), nest desertion or female predation (28%), and changes in water level (14%). Nest survival to fledging increased along the gradient of increasing levels of litter layer thickness, stagnating water, and vegetation height at the nest, and increasing height of the nest above the soil. Fledgling production tended to be lower than in the Biebrza Marshes (north-east Poland) habitats, assumed to be optimal for breeding. Otherwise, the reproductive success estimates did not deviate from nests found in the core breeding areas in north-east Poland or Belarus. Brood feeding frequency (15.5 ± 1.0/hour) was similar to that observed in the Biebrza Marshes. Our results suggest that the calcareous fens at the margins of the current species’ range provide a suitable breeding habitat. However, as the nesting area has contracted, management programmes tailored to the ecological requirements of the Aquatic Warbler are required.

Poisonous birds are rare but on New Guinea, including Indonesia’s easternmost provinces, no less than nine poisonous species, eight pitohuis and one species of ifrita, are found. Pitohuis when handled can cause sneezing with numbness and burning of nasal tissue and nausea in humans. In the bird markets of western Indonesia novelty birds are traded at a premium and overexploitation of popular songbirds leads traders to find replacement species to meet demand. We conducted over 800 surveys in the bird markets of Sumatra, Java, Bali, Lombok, and Sulawesi between 1994 and 2023 and from 2015 onwards we assessed the online trade in pitohuis and Blue-capped Ifrit Ifrita kowaldi. We identified the species, recorded their prices and location, and the date when the birds were offered for sale. We analysed temporal trends, volumes, prices, and geographical origin of the sellers. Between 1994 and 2014 we did not encounter a single pitohui in the Indonesian bird markets. In the following years we recorded 113 pitohuis in 12 bird markets and we recorded 199 pitohuis for sale online; 248 were variable pitohuis and 54 were Hooded Pitohui Pitohui dichrous. No ifritas were recorded. Most pitohuis were recorded in eastern Java and Bali. Prices differed between eastern Java (mean of US$93) and western Java and Bali (US$185), possibly suggesting pitohuis arrive from West Papua in eastern Java and from there make their way to the outer markets. Pitohuis are marketed as “Papuan Straw-headed Bulbuls”; the Straw-headed Bulbul Pycnonotus zeylanicus is a very popular and expensive songbird from Southeast Asia, including western Indonesia, that has become rare both in the wild and in the markets due to overexploitation. Discussions about pitohuis on online forums rarely mention “poisonous” but when it is mentioned traders dismiss this as something not to worry about and they claim it to be dietary-dependent. Poisonous pitohuis are novelty, as well as master, birds in Indonesia, where they are marketed for their song ignoring any negative side-effects of them being poisonous. The trade in novelty species, when detected early, does allow for the authorities to intervene in a timely manner to ensure that this trade does not impede their conservation.

There are six species of flamingos in the world, all under pressure from human activities in their wetland habitats. Obtaining global population estimates for flamingos is challenging because of their broad geographical range, nomadic movements, capacity for long-distance flight, and the complexity of international monitoring. Two species, the Andean Flamingo Phoenicoparrus andinus and Puna Flamingo P. jamesi, during key parts of their life cycle, use wetlands in the Andes of South America, where they coexist at various sites. We compiled historical information on population estimates and ecology for these two species and integrated data collected on regional simultaneous censuses to describe population trends, current and emerging threats, and provide recommendations for conservation action. Long-term population trends have been difficult to establish given the unreliability of population estimates prior to the late 1990s. Systematic, regional censuses carried out regularly since 1997 have produced robust population estimates for the Andean and Puna flamingos (most recently, 78,000 and 154,000, respectively) and show populations of both species to be stable and increasing. Increasingly rapid changes in wetlands caused by human activities such as industrial-scale mining in breeding and foraging sites in the high Andes wetlands, and agro-industrial activities in their lowland wintering sites, focused on areas of the highest concentrations of flamingos pose threats to their survival and ability to reproduce. In addition, climate change is projected to reduce wetland habitats and some localised effects have already been detected. Continued research on the ecological drivers of flamingo abundance, movements, and population genetics to understand population structure and dynamics are necessary, as well as the identification of response variables to changing environmental conditions. Interdisciplinary and systems-level approaches in the context of international collaboration in monitoring and conservation planning among a diversity of stakeholders will be required to safeguard flamingo populations and wetland habitats.

Resource partitioning is a critical mechanism underlying the coexistence of close relative species that feed on similar resources. Based on foraging data, we built a plant–seedeater interaction network for three sympatric species of Neotropical seedeaters – namely Tropeiro Seedeater Sporophila beltoni, Black-bellied Seedeater Sporophila melanogaster, and Tawny-bellied Seedeater Sporophila hypoxantha, and tested to what extent the three species shared resources. The interaction network was non-nested and modular, forming three modules, each one comprising one seedeater species and their most consumed plants, indicating the existence of resource partitioning. Modules may result from multiple non-exclusive factors, including differences among seedeater species in habitat use, bill sizes, feeding habits, structure of vegetation for nesting, and abiotic factors that influence plant composition. Our results indicate that the effective conservation of these species requires the protection of areas that include the three distinct subsets of plants used by these birds during the breeding season and also indicates which plants may be used for the restoration of grasslands in the region.

Wilkins’s Finch Nesospiza wilkinsi is endemic to Nightingale Island (2.5 km2), Tristan da Cunha. It feeds on the woody fruits of the Island Tree Phylica arborea and in 2017 had a population of 120 breeding pairs. In 2021 it was uplisted from “Endangered” to “Critically Endangered” following damage to P. arborea woodland during severe storms in 2019. During a brief visit to Nightingale in February 2024, we confirmed that the finch population in the area of storm-damaged woodland has decreased by up to 75%, but the density in other areas was similar to that prior to 2019. Extrapolating from the 2017 survey, we estimated the current population to be 60–90 breeding pairs. Surveys of P. arborea structure in the storm-affected area indicated that some large trees had survived, despite being flattened, that recruitment of new trees is occurring, and that fruit loads on surviving trees are similar to those in 2017. Satellite imagery from 2005 showed similar woodland loss during another severe storm in 2001 to that experienced in 2019, indicating that the finch has survived similar events in the past. Coupled with the successful release of a biological control agent to limit the impact of the introduced brown soft scale Coccus hesperidum on Phylica fruit production, the future prospect for Wilkins’s Finch is less bleak than previously thought. However, the risk that global warming is increasing the frequency of severe storms remains a concern. Planting more woodland patches in sheltered areas would help to offset future storm damage.

In the Anthropocene, recognising nature’s role in human well-being is pivotal for biodiversity conservation. Despite their significance, knowledge gaps persist regarding ecosystem services, even for well-studied species like vultures. Our study focuses on the Griffon Vulture Gyps fulvus in Sardinia, Italy, exploring their cultural and regulating services, including carcass disposal and resulting greenhouse gas (GHG) mitigation. Through surveys of natural reserve visitors and data on carcass provision and GHG emissions, we assess public perception, economic value, and environmental impacts associated with vultures. The public perception of Griffon Vultures is predominantly positive, with a strong acknowledgment of their role in disease prevention and carcass disposal, highlighting their contribution to regulation services. Furthermore, vultures are widely recognised as a key element characterising the agropastoral landscapes of Sardinia, underscoring their cultural importance. The economic evaluation, through willingness to pay for vulture-watching and photography opportunities, indicates a significant appreciation of these birds, with almost three-quarters of respondents willing to pay an entrance fee at vulture observation sites. We also show that supplanting the disposal role of vultures at studied feeding sites (during 2017–2022) would result in the emission of 96 tons of CO2 equivalent, which highlights the critical role of vultures in climate mitigation. This study not only sheds light on the ecological and cultural significance of Griffon Vultures in Sardinia but also underscores the economic and environmental benefits of their conservation. It emphasises the need for continued efforts in vulture conservation, integrating ecological, cultural, and economic perspectives to foster a sustainable coexistence between humans and wildlife.

We report the non-breeding range of an adult Rapa Shearwater Puffinus myrtae, as estimated from data collected by one light logger deployed from 31 August 2019 to 22 July 2020. The Rapa Shearwater is classified as “Critically Endangered”, with a strong decline in breeding numbers reported recently. As the species is threatened by various introduced mammals on the breeding colonies, the main objective of this tracking essay was to identify the oceanic regions where the birds forage during the non-breeding season. The non-breeding range of this bird was located south-east of Rapa Island, where fishery activities are limited. The conservation efforts for the Critically Endangered Rapa Shearwater should first focus on securing mammal-free sites for breeding colonies.

Species’ declines are caused by a combination of factors that affect survival and/or breeding success. We studied the effects of a set of environmental and anthropogenic variables on the disappearance of Canarian Houbara Bustards Chlamydotis undulata fuertaventurae on Fuerteventura (Canary Islands), once the main stronghold of this endangered bird. Of 83 male display sites detected in 1997–1998, only 29 remained occupied in 2020–2021 (a 65% decrease in only 23 years). We compared habitat quality, density of conspecifics, other steppe birds and crows, presence of human infrastructure, and degree of environmental protection between these 29 extant sites and the 54 extinct sites using univariate analyses and generalised linear models (GLMs). The most influential variable in the abandonment of display sites was the Normalised Difference Vegetation Index (NDVI), an indicator of green vegetation productivity, which suggests a strong effect of habitat aridification due to climate change on the population’s extinction process. Powerline density was the second most important factor. This suggests that houbaras have survived where a greater abundance of food resources has enabled a higher breeding success, and where powerline fatalities have caused lower mortality over the years. Higher densities of houbaras, and other steppe birds and crows at extant display sites confirmed the better habitat quality in these areas. Extant display sites, located generally in protected areas, also had lower densities of human infrastructure (e.g. buildings, roads). We discuss the conservation implications of these results and provide management recommendations for this endangered subspecies.

As a result of increasingly intensified agricultural practices in Europe over the last century, agroecosystems have experienced severe biodiversity declines. Among the species experiencing negative population trajectories in agricultural habitats are meadow and farmland birds, which have suffered a loss in both habitat and food availability in cultivated fields. In Denmark, biotope plans (a requirement to establish small agro-environmental habitats on properties with stocking of game birds) have been implemented as a measure to mitigate biodiversity declines in the agricultural landscape and, in this paper, we investigate to what extent these initiatives fulfil the intended purpose with respect to birds in the breeding season. We demonstrate that some initiatives like hedgerows, areas of open vegetation, scrub, and lakes seemed to increase avian diversity locally, but also that other measures such as vegetation strips, grass strips, and bare soil strips had little effect given the current implementation of these initiatives. Benefitting species were mostly scrub- and woodland species that now inhabited previously open landscapes after the establishment of suitable habitats, and the initiatives failed to show clear positive effects on meadow birds and farmland birds for which they were originally intended. The most commonly registered species in our data set was (released) Pheasant Phasianus colchicus, which emphasised that the stocking of game birds can have a clear effect on avian species composition in areas where this practice is exercised. Future studies are needed to clarify how this stocking may affect local biodiversity of different taxonomic groups.

Reintroduction includes the captive propagation and movement of extirpated animals or plants into areas of historical and native distribution. Many biotic or abiotic factors can affect a founder population when small numbers are released into unfamiliar novel environments, particularly at the early stage of reintroduction. The inclusion of behavioural and ecological components plays a crucial role in the decision-making process of endangered species conservation efforts such as reintroduction. Since the resident population of Oriental Storks Ciconia boyciana was locally extirpated in South Korea in 1971, its founders have been established through reintroduction since 2015. The aim of this study was to investigate the demography, habitat use, and movement patterns of stork founders using the first two-year demographic and tracking data. Stork founders maintained their population size, which slightly increased in the long term. The patterns of habitat use and movement depended on rice paddy fields for foraging and breeding along with mixed effects of breeding status and season. Considering ecological and life history-related perspectives, we also discuss the potential adaptiveness of founder Oriental Storks as a resident population in a novel environment in South Korea.

Forests of urban/suburban areas are being increasingly restored, but before/after-control/impact studies addressing effects on biodiversity in peri-urban forest restorations are virtually lacking. Using a before/after-control/impact (BACI) design, we explored the effects on birds (commonly used as indicators for restoration impacts) of small-scale restoration interventions in 2019 targeting residual forests north of Milan, in the largest Italian conurbation, with trees and shrub planting around existing patches or in formerly cultivated areas. Birds were surveyed in 2018, 2019, and 2021, at 20 intervention and 20 control sites. We evaluated the short-term effects of restoration by analysing changes in avian communities (i.e. richness, richness and abundance of forest specialists, single species’ abundance), considering the effect of year and intervention (i.e. before/during/after intervention). Species richness of breeding birds was largely unaffected by on-going interventions, while it was positively related to concluded restoration. The abundance of five individual species varied according to restoration: on-going interventions had positive effects on two species, Common Blackbird Turdus merula and Hooded Crow Corvus corone cornix, and negative effects on Barn Swallow Hirundo rustica, while concluded restoration positively affected two species, Common Blackbird Turdus merula again, and the forest specialist Marsh Tit Poecile palustris. Even small-scale interventions in peri-urban areas may provide tangible benefits to breeding birds in the short term: peri-urban forest restoration could contribute to biodiversity conservation.

Heat stress from high temperatures has been recognised as a threat to several bird species and one that is likely to increase in severity and frequency as a result of global environmental change. Many seabirds are particularly vulnerable as their adaptations to forage in cold water can make it hard for them to resist heat gain while on land. The African Penguin Spheniscus demersus forages in cool water (10–20°C) but breeds and moults on land where temperatures can exceed 30°C. Little is known about its thermal physiology and when heat stress will occur. Here, we provide the first account of changes in body temperature and behaviour in African Penguins in response to an experimental increase in ambient temperature from 20°C to 35°C. Surprisingly, the highest body temperature observed (39.2°C) was recorded at the start of the study. Presumably, this response in body temperature was due to the stress of transport and handling. Penguins returned to normal body temperature (37.3°C) after 3.5 hours and maintained normothermia for roughly an hour. We then observed the onset of heat storage at an ambient temperature of 29°C, whereafter body temperature increased steadily at a rate of ca.0.2°C per 1°C increase in ambient temperature. Panting commenced at an ambient temperature of 31.4°C, when body temperature was 37.8°C. In addition to panting, penguins changed their posture to facilitate heat dissipation by standing, raising their heads, and extending their flippers. Our results corroborate field observations and support the argument that African Penguins are highly vulnerable to heat stress in the near future as extreme heat events become more severe and frequent due to climate change. Our results also confirm that penguins are sensitive to handling, which elicits a hyperthermic response. Given the general sensitivity of penguins to disturbance, from a conservation perspective, we advise that cautionary measures be implemented at colonies during critical life-history stages.