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.

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.

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.

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.

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.

We investigated Eurasian Skylark Alauda arvensis avoidance of powerlines and their pylons by assessing the spatial distribution of Skylark territories. We mapped territory centres in a central German agricultural landscape during 2020 and used Bayesian logistic regression models to test if distances from powerlines and pylons are predictive of the presence of territories. We also tested other possible predictors, namely, nearest distances from roads, vertical structures, wind energy plants, settlements, as well as the nearest pylon type and vegetation. Distances from the nearest road and settlement were positively correlated with the probability of territory occurrence. However, distance from powerlines and pylons were not significant predictors. Skylarks were also more likely to establish territories in areas where winter grain is present. We conclude that powerlines are unlikely to lead to significant habitat reduction for the Skylark that would impact local populations. We can, however, confirm avoidance behaviour towards roads and settlements, as well as a preference for areas with winter grain because the crop’s growth period coincides with the start of the breeding season, initially providing vegetation of a suitable height and coverage.

The ʻuaʻu, or Hawaiian Petrel Pterodroma sandwichensis, is an endangered seabird endemic to the Hawaiian Islands. Genetic, morphometric, and behavioural differences have previously been found between different island populations of the species. Understanding the breeding phenology of different populations of ʻuaʻu is therefore vital for conservation actions targeting the species. To assess breeding phenology of ʻuaʻu on the islands of Kauaʻi and Lānaʻi, two main techniques were used over a 12-year period: direct burrow monitoring and burrow cameras. The breeding phenology of the ʻuaʻu is described based on this data. On Kauaʻi, breeding birds arrive in the middle of April, undergo an exodus of approximately one month, and return to lay in the beginning of June. Incubation continues until early August, followed by chick-rearing, which ends on average two weeks before the chick fledges. Fledging starts in mid-October, peaks in mid-November, and ends in the third week of December. Lānaʻi birds arrive two weeks earlier and fledge one week earlier than on Kauaʻi. On both islands breeding was asynchronous with a 68-day (Kauaʻi) and 48-day (Lānaʻi) gap between first and last fledging birds. Considering phenology data across its entire Hawaiian range, ʻuaʻu first arrive on east Maui, then Lānaʻi, Hawaiʻi Island, and Kauaʻi in that order. These differences in timing presumably reflect and/or reinforce genetic differentiation between subpopulations of the species. The utility of this information is discussed in terms of directing management actions towards key periods of vulnerability to introduced predators, including peak incubation, chick emergence, and chick exercise periods. Description of island-specific phenologies is also critical to inform efforts to rescue fledglings disoriented by artificial light, mitigate powerline collisions, and refine existing monitoring and restoration projects. Future work using acoustic monitoring and data collected at social attraction sites is recommended for assessing the phenology of non-breeders at colonies.

Incomplete knowledge of the drivers of local productivity may contribute to the on-going decline of farmland bird populations despite conservation efforts. We therefore investigated spatial and temporal variation in breeding phenology, nest habitat, and nest survival in the Corn Bunting Emberiza calandra, a species of conservation concern in central and western Europe. Among 225 nests from seven study areas in cropland-dominated, mixed, and grassland-dominated landscapes, nesting phenology spread between April and August, started earlier at lower altitudes, and progressed from grassland to arable crop and agri-environment scheme flower field habitats. Nest habitats varied substantially between years, but most nests were placed in cultivated land where they were prone to fail due to land-use operations. Nest survival differed markedly between habitats, being lowest in second-year flower fields and highest in fallow grassland. Since we protected known nests, raw survival estimates only account for “natural” nest losses, e.g. due to adverse weather or predation. To estimate additional “anthropogenic” nest losses, we calculated probabilities of nesting schedules to conflict with patch-specific land-use dates. After taking into account the estimated conflict probabilities of 0.56 for mowing, 0.64 for clover harvest, and 0.38 for grazing, habitat-specific “total Mayfield nest survival” estimates declined to 21%, 13%, and 20% for meadows, alfalfa/clover-grass leys, and pastures, respectively. These habitats held about two thirds of nests in mixed landscapes, highlighting the relevance of land use-driven nest losses. To enhance productivity beyond the thresholds required for local population persistence, we propose refined conservation schemes that improve nest survival within production farmland, best coupled with the development of prolific “Corn Bunting landscapes”.

Andean Condor Vultur gryphus populations are particularly low in the northern Andes. The species is considered nearly eradicated from Venezuela and listed as “Endangered” in Ecuador and “Critically Endangered” in Colombia. Even though it is severely endangered, the size of the Colombian condor population remains unknown. Using a citizen science-based approach, we conducted the first Andean Condor count for Colombia with the help of 207 observers at 84 simultaneous observation points. We used N-mixture models for spatially replicated counts to estimate the condor population. The total number of condors recorded simultaneously was 63 individuals, and we estimated a population size of 175–269 individuals using a maximum likelihood approach and 165–222 and 172–229 for the two best models using the Bayesian approach. Adults were observed more frequently than juveniles (1:0.43), a common pattern among raptors related to the higher mortality rates of immature birds, which is a prominent conservation concern due to the status of the species and the threats it currently faces throughout the northern Andes. Our citizen science-based study made it possible to gather, for the first time in Colombia, consolidated information on the status of the Andean Condor population using a standardised methodology to provide a reference for future counts and conservation actions, both at the national level and throughout the geographical range of the species.

Obligate avian scavengers, such as the “Critically Endangered” California Condor Gymnogyps californianus, face significant threats from human activities and environmental changes. This study examines the home range and presence of reintroduced California Condors in a protected area in Baja California, Mexico, focusing on the influences of seasonality, biological factors, and food supplementation. Using spatial data collected over 12 months with telemetry equipment, we analysed condor movements within and beyond the boundaries of the Parque Nacional Sierra de San Pedro Mártir. Our findings reveal that condors spend over half their time within the protected area, with an increased presence during winter months. Supplementary feeding programmes significantly increased condor presence within the park, particularly in spring and summer. Home range analyses showed that season significantly influenced home range sizes, with smaller ranges observed during winter compared with other seasons. Additionally, male condors had larger home ranges than females during spring, but no significant sex differences were observed in other seasons. Age did not have a significant effect on home range size. This study emphasises the importance of protected areas and supplementary feeding programmes in condor conservation, highlighting the necessity of continuous monitoring and management to help support this iconic species.

The Santa Marta Sabrewing Campylopterus phainopeplus is listed as a “Critically Endangered” hummingbird endemic to the Sierra Nevada de Santa Marta (SNSM) in Colombia. Prior to 2022, there were only three documented sightings of the sabrewing since it was described in 1879, including only one record between 1946 and 2022. As a result, this “lost” species has long been one of the most poorly known birds in Colombia. We located a resident population of Santa Marta Sabrewing along the Guatapurí River near the Chemesquemena and Guatapurí villages in July 2022, and at its type locality, San José, in January 2023. Based on historical data and newly collected field observations, we assess the species’ status and describe aspects of its natural history and ecology. Our review indicates that the species has been frequently misidentified in the past, and that to date, documented evidence of its presence is limited to four localities, all of them restricted to the south-eastern slope of the SNSM, along the mid Guatapurí River basin. Consequently, this bird appears to represent a case of microendemism. This species is likely to remain listed as Critically Endangered until conclusive evidence suggests otherwise. Field observations indicate that the species is highly associated with watercourses, where males hold year-round territories and form leks. We obtained records of males in mid-elevation habitats (1,150–1,850 m) for 16 consecutive months between July 2022 and October 2023, suggesting that the species might not be an elevational migrant, as previously speculated. More information is needed to understand the species’ ecology so that effective conservation actions can be designed in collaboration with the indigenous communities with which the species coexists.

Birds show considerable spatial and temporal fluctuations in their abundance due to variations in habitat conditions. The lowland wetlands of the Pampas region in Argentina are key wintering areas for two flamingo species. The Chilean Flamingo Phoenicopterus chilensis is a year-round resident, while the Andean Flamingo Phoenicoparrus andinus is a partial altitudinal migrant that uses these wetlands in winter when some of the wetlands in the high Andes freeze over. We studied the association between the annual abundance of both flamingo species, wetland condition (water surface area and water salinity), and environmental conditions (flooding) driven by the El Niño Southern Oscillation (ENSO) over 15 consecutive winters (July–August 2008–2022) in 24 lowland wetlands in central Argentina. There were notable differences in wetland surface area and water conductivity between years, with some wetlands ranging from flooded to almost dried out. For any given year, there were also large differences in water surface area and water conductivity between wetlands. Both flamingo species showed marked fluctuations in abundance over the study period. Each year, the Chilean Flamingo was more abundant than the Andean Flamingo. The Chilean Flamingo was recorded at least once in every wetland, while the Andean Flamingo was absent from three wetlands and was not observed in two years during the study. The Chilean Flamingo was recorded in wetlands covering a larger range of water conductivity values than the Andean Flamingo (2.53–58.23 ms/cm vs 2.94–16.20 ms/cm, respectively). The abundance of both flamingo species was higher at intermediate water conductivity values and decreased at higher or lower values. These results show that these lowland wetlands are subjected to strong interannual variation in climatic conditions which affect lake conditions, and thus the abundance of both flamingo species, highlighting the importance of conserving wetlands encompassing a broad range of environmental conditions.

Persecution for belief-based uses is a major threat to raptors in West Africa. Critically Endangered Hooded Vultures Necrosyrtes monachus are traded openly in West African vodun (also known as voodoo or fetish) markets in Benin, despite national laws protecting this species. We interviewed 115 vendors selling Hooded Vultures and/or their body parts at nine different markets in southern Benin to understand the extent and drivers of this illegal trade. Over four months, we counted a total of 522 Hooded Vultures in market stalls, including whole dried vulture carcasses (73.4% of vulture products offered for sale), vulture heads (17.2%), and live birds (9.4%). Vultures offered for sale originated from at least 10 foreign countries, suggesting there are far-reaching impacts of illegal trade on Hooded Vultures. Vodun practitioners sacrifice and consume vultures in the belief these practices will protect them from witchcraft and achieve other supernatural aims, and the resulting high demand for vultures has driven the price of a Hooded Vulture to exceed the average monthly income in Benin. Despite serious legal, conservation, and animal welfare concerns, wildlife trade for belief-based use is thriving and growing in West Africa, and our findings highlight that legislation aimed at protecting vultures in Benin appears to be currently ineffective. From our discussions with traders, it appears that low education levels, weak law enforcement, and disregard for legislation contribute to this trade that threatens remaining vultures across West Africa. Public awareness campaigns to educate residents about conservation laws and improved law enforcement are urgently needed to mitigate on-going threats to this and other Critically Endangered species.

This study presents a novel approach using machine learning, specifically Random Forest modelling, to create a sensitivity map that addresses the conflict between offshore wind farms (OWFs) and wintering waterbirds in the southern Baltic Sea. This region is crucial or of great importance for wintering species such as the Long-tailed Duck Clangula hyemalis and Velvet Scoter Melanitta fusca. In 2020, the southern and central Baltic Sea hosted approximately one million wintering birds, including over 560,000 Long-tailed Ducks (35% of the species’ biogeographical population), 230,000 Velvet Scoters (41% of the global population), and 4,500 Black Guillemot Cepphus grylle (8% of the Baltic population). Within the Polish Exclusive Economic Zone (PEEZ), 21 wind farms are planned, totalling a capacity of 17.6 GW with an estimated 1,164 turbines. To assess potential risks, a Normalised Overlap Index (NOI) was calculated for each wind farm, quantifying the level of potential threat to wintering birds. High conflict zones, such as the Southern Middle Bank and Pomeranian Bay, were identified, where wind farms significantly overlap with areas of high bird density. Although the wind farms do not intersect with Natura 2000 sites, partial overlaps with Important Bird Areas (IBAs) were noted. The method developed in this study not only addresses the challenges in the Baltic Sea but also offers potential applications in other marine and terrestrial environments. This framework provides a novel tool for evaluating and mitigating the impacts of renewable energy development on wildlife, contributing to the sustainable expansion of green energy solutions globally.

The Puerto Rico Plain Pigeon Patagioenas inornata wetmorei suffered a severe population decline after hurricanes Irma and Maria in September 2017. We used distance sampling to estimate abundance (density and population size) in April–June 1986−2024, accounting for changes in detection probability. We used the distance-sampling abundance estimates to populate a Bayesian state–space logistic model and update posterior estimates of population carrying capacity, maximum population growth rate, population recovery time, and predicted abundance in April–June 2025−2034, accounting for observation and process variances. In addition, we used predicted abundance to assess potential extinction risk (probability Pr[N2025−2034 = 0|data]), population self-sustainability above 5,000 individuals (Pr[N2025−2034 >5,000|data]), and population surpassing the 2.5th percentile of carrying capacity (Pr[N2025−2034 >30,000|data]). The population has not recovered from the hurricanes, with estimated density averaging 0.0015 individuals/ha (bootstrapped standard error [SE] = 0.0006) and population size averaging 1,097 individuals (SE = 455) at the 749,000-ha survey region in April–June 2018−2024. Posterior mean estimates were 41,580 individuals (Markov Chain Monte Carlo standard deviation [SD] = 8,052) for population carrying capacity, 0.183 (SD = 0.056) for maximum population growth rate, six years (SD = 2) for recovery time, and 7,173 individuals (SD = 12,309) for predicted abundance in April–June 2025−2034. The population may reach self-sustainability levels (range Pr[N2025−2034 >5,000|data] = 0.326−0.631) but currently is undergoing a prolonged bottleneck and may become extinct (range Pr[N2025−2034 = 0|data] = 0.199−0.332), particularly if reproduction continues to be mostly unsuccessful, anthropogenic disturbances remain unabated, and on top of that another devastating hurricane makes landfall during the next 10 years. The Puerto Rico Plain Pigeon subspecies is in urgent need of management aiming to increase and maintain abundance above 5,000 individuals but preferably surpassing the 2.5th percentile of population carrying capacity as in the late 1990s (range Pr[N2025−2034 >30,000|data] = 0.000−0.181).

We review the conservation status of two small rail species breeding in the Galápagos Islands: the endemic Galápagos Rail Laterallus spilonota and the native Paint-billed Crake Neocrex erythrops, widely distributed on the South American mainland. Using distance sampling with point counts, we estimated population sizes across islands with suitable habitat from 2015 to 2025. In 2022, we reassessed long-term trends for the Galápagos Rail on Santa Cruz Island, following the monitoring protocol used in earlier censuses (1986, 2000, 2007). We estimated the Galápagos Rail population at 32,300 pairs across seven islands, including a small, newly recorded breeding population on Pinzón and Floreana, where we rediscovered the rail in 2025. Additional breeding populations of unknown size exist in the humid zones of the two northern volcanoes of Isabela and on adjacent Fernandina. The largest population, on Santiago (22,400 pairs), has recovered remarkably over 40 years since goats and other herbivores were eradicated. We found the Galápagos Rail predominantly in the humid highlands, although a few pairs were recorded in the mangrove forests of Isabela Island. The species is absent from San Cristóbal Island. On Santa Cruz it showed a clear increase between 2007 and 2022. The Paint-billed Crake breeds on the four inhabited islands (Floreana, Isabela, San Cristóbal, and Santa Cruz), with at least 6,300 pairs. It was mainly found in grasslands and open woodlands within agricultural areas at lower altitude than the Galápagos Rail, resulting in minimal range overlap. Its population and range have expanded, especially on Santa Cruz. The significantly higher recent population estimate for the Galápagos Rail compared with past estimates, along with positive trends on at least three islands, warrants reclassifying the species IUCN Red List status from “Vulnerable” to “Near Threatened”.

The endemic Crow Honeyeater Eugymnomyza aubryana of New Caledonia is classified as “Critically Endangered”. Its rainforest habitat on mainland Grande Terre has been reduced by around 80% and the remaining habitat is highly fragmented. It is likely that by early 1900, anthropogenic changes had split the Crow Honeyeater’s distribution into two populations: one in the north of the island and one in the south separated by over 200 km. From 2011, the species was only known to be present in the south of Grande Terre with its distribution centred on the Blue River Provincial Park. It is essential for the species’ survival to protect its remaining natural habitat and its nests from predators.