Information about population sizes, trends, and habitat use is key for species conservation and management. The Buff-breasted Sandpiper Calidris subruficollis (BBSA) is a long-distance migratory shorebird that breeds in the Arctic and migrates to south-eastern South America, wintering in the grasslands of southern Brazil, Uruguay, and Argentina. Most studies of Nearctic migratory species occur in the Northern Hemisphere, but monitoring these species at non-breeding areas is crucial for conservation during this phase of the annual cycle. Our first objective was to estimate trends of BBSA at four key areas in southern Brazil during the non-breeding season. We surveyed for BBSA and measured vegetation height in most years from 2008/09 to 2019/20. We used hierarchical distance sampling models in which BBSA abundance and density were modelled as a function of vegetation height and corrected for detectability. Next, we used on-the-ground surveys combined with satellite imagery and habitat classification models to estimate BBSA population size in 2019/20 at two major non-breeding areas. We found that abundance and density were negatively affected by increasing vegetation height. Abundance fluctuated five- to eight-fold over the study period, with peaks in the middle of the study (2014/15). We estimated the BBSA wintering population size as 1,201 (95% credible interval [CI]: 637–1,946) birds in Torotama Island and 2,232 (95% CI: 1,199–3,584) in Lagoa do Peixe National Park during the 2019/20 austral summer. Although no pronounced trend was detected, BBSA abundance fluctuated greatly from year to year. Our results demonstrate that only two of the four key areas hold high densities of BBSA and highlight the positive effect of short grass on BBSA numbers. Short-grass coastal habitats used by BBSA are strongly influenced by livestock grazing and climate, and are expected to shrink in size with future development and climatic changes.

Based on censuses in 2021 and 2022 of Bristle-thighed Curlews Numenius tahitiensis on 10 atolls of French Polynesia, the species has declined by c.50% over the last two decades. While the species has recently been down-listed from “Vulnerable” to “Near Threatened”, these new data would qualify it for an “Endangered” Red List status. The non-breeding population on Tuamotu numbers approximately 1,000 curlews and up to 1,500 individuals in all of Eastern Polynesia. On uninhabited islands, the expansion of copra (coconut pulp) exploitation has caused long-term disturbance for curlews, increased predation by pet dogs, and introduced or reinforced non-native rat populations. Climate change, particularly sea-level rise, will add to changes in land use that shrink the suitable habitat for Bristle-thighed Curlews in French Polynesia. As this study shows, obtaining population trends for species breeding in remote areas may best be achieved through surveys at key non-breeding sites.

There is serious concern for the future of a wide range of birds in Java and elsewhere in Indonesia due to both loss of habitat and trapping for the cagebird trade (the so-called “Asian Songbird Crisis”). Despite this concern, few data on presence and abundance of key species exist. We provide such data on 184 bird species from over two years of biodiversity surveys from 37 sites on 12 mountains in West and Central Java. Many of these species are heavily traded, endemic, and globally threatened. Several of the threatened endemics, notably Javan Trogon and Javan Cochoa, were often recorded, in terms of both geographical spread and numerical abundance. Rufous-fronted Laughingthrush, Spotted Crocias, and Orange-spotted Bulbul, believed to be threatened by trapping for the songbird trade, appear to remain fairly widespread. By contrast, Brown-cheeked Bulbul, Chestnut-backed (Javan) Scimitar-babbler, Javan Oriole, and especially Javan Blue-flycatcher, recorded on just a single occasion, and Javan Green Magpie, which we failed to record with certainty, now appear to be extremely rare. Our encounter rates, while not pinned to specific mountains for security reasons, represent an important baseline against which future changes in abundance can be gauged.

Traditional policies on using wild species are critical in developing scenarios for community engagement in conserving wild species populations. As such, this study examines the traditional practice of harvesting eggs from Moluccan Scrubfowl Eulipoa wallacei on Haruku Island, Indonesia, and its implications for bird population conservation. Using a closed-ended questionnaire, we surveyed 200 respondents in the productive age group (aged 15–65 years). It was found that most of the community supported adopting the traditional policies due to the high demand for eggs, which required daily harvesting. According to the community, egg harvesting has no adverse effect on bird populations, but hunting and habitat destruction does reduce the number of eggs available for harvesting. The community concluded that traditional conservation policies prioritise the conservation of adult birds and their habitats, not bird eggs. Particular attention should be paid to egg conservation efforts by establishing a quota for egg harvesting and limiting egg-harvesting time. Conservation efforts must also take into account the growing community awareness of the importance of conserving Moluccan Scrubfowl eggs.

Understanding the distribution and extent of suitable habitats is critical for the conservation of endangered and endemic taxa. Such knowledge is limited for many Central African species, including the rare and globally threatened Grey-necked Picathartes Picathartes oreas, one of only two species in the family Picathartidae endemic to the forests of Central Africa. Despite growing concerns about land-use change resulting in fragmentation and loss of forest cover in the region, neither the extent of suitable habitat nor the potential species’ distribution is well known. We combine 339 (new and historical) occurrence records of Grey-necked Picathartes with environmental variables to model the potential global distribution. We used a Maximum Entropy modelling approach that accounted for sampling bias. Our model suggests that Grey-necked Picathartes distribution is strongly associated with steeper slopes and high levels of forest cover, while bioclimatic, vegetation health, and habitat condition variables were all excluded from the final model. We predicted 17,327 km2 of suitable habitat for the species, of which only 2,490 km2 (14.4%) are within protected areas where conservation designations are strictly enforced. These findings show a smaller global distribution of predicted suitable habitat forthe Grey-necked Picathartes than previously thought. This work provides evidence to inform a revision of the International Union for Conservation of Nature (IUCN) Red List status, and may warrant upgrading the status of the species from “Near Threatened” to “Vulnerable”.

This is the fourth comprehensive assessment of the population status of all wild bird species in Europe. It identifies Species of European Conservation Concern (SPECs) so that action can be taken to improve their status. Species are categorised according to their global extinction risk, the size and trend of their European population and range, and Europe’s global responsibility for them. Of the 546 species assessed, 207 (38%) are SPECs: 74 (14%) of global concern (SPEC 1); 32 (6%) of European concern and concentrated in Europe (SPEC 2); and 101 (18%) of European concern but not concentrated in Europe (SPEC 3). The proportion of SPECs has remained similar (38–43%) across all four assessments since 1994, but the number of SPEC 1 species of global concern has trebled. The 44 species assessed as Non-SPECs in the third assessment (2017) but as SPECs here include multiple waders, raptors and passerines that breed in arctic, boreal or alpine regions, highlighting the growing importance of northern Europe and mountain ecosystems for bird conservation. Conversely, the 62 species assessed as SPECs in 2017 but as Non-SPECs here include various large waterbirds and raptors that are recovering due to conservation action. Since 1994, the number of specially protected species (listed on Annex I of the EU Birds Directive) qualifying as SPECs has fallen by 33%, while the number of huntable (Annex II) species qualifying as SPECs has risen by 56%. The broad patterns identified previously remain evident: 100 species have been classified as SPECs in all four assessments, including numerous farmland and steppe birds, ducks, waders, raptors, seabirds and long-distance migrants. Many of their populations are heavily depleted or continue to decline and/or contract in range. Europe still holds 3.4–5.4 billion breeding birds, but more action to halt and reverse losses is needed.

Spix’s Macaw Cyanopsitta spixii is one of the most endangered Neotropical Psittacidae species. Extinct in the wild in the year 2000, in June 2022 the first cohort of C. spixii was reintroduced to its original habitat. For a successful reintroduction of the species, it is necessary to examine the viability of the population against natural and external threats and the environmental requirements for success. Thus, this paper presents a “Population Viability Analysis” (PVA) for Spix’s Macaw. It used the Vortex and RangeShiftR software, biological and environmental data from a bibliographic survey, and information provided by the field team responsible for the reintroduction of the species, and who work directly with the species in captivity. We found that the minimum viable population (MVP) for reintroduction of the species is 20 individuals. However, considering the impact of disease, drought, hunting, and illegal trafficking, this population can only persist if the release of individuals from captivity occurs annually over the next 20 years combined with the reforestation of natural habitat to support population growth.

Vultures are long-lived species sensitive to human-caused mortality that has already determined a widespread collapse in Asian and African populations. They provide significant ecosystem services (regulatory and cultural) consuming livestock carcasses and saving greenhouse gas emissions, favouring nutrient recycling, environmental sanitation, and providing financial revenue. Appraising the incidence and causes of mortality could help to improve management and conservation actions. We compiled records of reported mortalities for the reintroduced Griffon Vulture Gyps fulvus population of the central Apennines in Italy (123 cases, July 1994–December 2020). The average mortality was 4.69 vultures per year (± 1.14 SE), with no significant temporal trend. The peak of mortality events, estimated by harmonic regression analysis, was in March, while the minimum occurred in October. No differences were found among age classes and sex ratio mortality was established at 1.43:1 (M:F, N = 68). Out of 103 (83.7%) vultures which underwent a post-mortem and toxicological screening, 53% were poisoned, mainly by carbamates, and 27% died of unknown causes. Overall, direct or indirect anthropogenic mortality caused 67% of deaths. Even considering an inherent bias associated with reported mortality as to the prevalence of causes of death and estimation of mortality rates, the overwhelming relevance of poisoning highlights that existing anti-poisoning efforts should be refined and incorporated into a coordinated multidisciplinary strategy. A standardised approach, from vulture carcass discovery to post-mortem procedures and toxicological analysis, should be applied to reduce uncertainty in the determination of causes of death, increasing effectiveness in the prosecution of wildlife crimes. As most of the poisoning cases affecting the Griffon Vulture population in the central Apennines likely represent a side (though illegal) effect of retaliatory efforts to defeat livestock predators, effective strategies in reducing human–wildlife conflicts should be applied.

The Taita Falcon Falco fasciinucha is known to occur and breed at only a few locations in eastern and southern Africa and is currently listed as globally “Vulnerable” and “Critically Endangered” in South Africa. An accurate estimation of its conservation status is however hampered by a lack of data and understanding of the species’ habitat requirements and competitive interactions with congeners. Our aim was to address some of these knowledge gaps. We conducted cliff-nesting raptor surveys across a substantial area of the Mpumalanga/Limpopo escarpment in north-eastern South Africa and modelled habitat suitability for nesting Taita Falcons in relation to the proximity of conspecifics and a community of five other sympatric cliff-nesting raptor species, and in relation to a suite of biotic and abiotic environmental variables. Results suggested the location of Taita Falcon nest sites was negatively associated with distance to the nearest pair of conspecifics and the nearest pair of Lanner Falcons Falco biarmicus, and positively associated with tracts of intact, unfragmented forest and woodland around the base of the cliffs. Our results indicated that Taita Falcon and Lanner Falcon appeared to be responding in opposite ways to a directional change in environmental conditions. This response appeared to be detrimental to Taita Falcon and beneficial to Lanner Falcon. Furthermore, the degradation and destruction of Afrotropical woodland and forest is a documented and ongoing reality, both locally and across much of the Taita Falcon’s global distribution. We argue that our findings are sufficient to justify uplisting Taita Falcon to globally “Endangered”.

Frigatebirds have been in taxonomic oblivion for nearly a century. A new genetic study by Martins et al. (2022) provides a stimulus and potential basis for a long-overdue modern review, which might lead to recognition of up to five new species-level taxa, two of which would be “Critically Endangered” globally and may already be effectively extinct. Even some of the more widespread frigatebird taxa are subject to multiple anthropogenic threats and, outside strictly protected and managed areas, may already be in serious decline. Seabird experts and organisations need urgently to review all available data relevant to frigatebird taxonomy and populations, collect additional material for genetic analysis, undertake new assessments of conservation status, and (in collaboration with appropriate regulatory authorities) propose and execute appropriate conservation and management actions.

Southern Black Korhaan is “Vulnerable” to extinction and a South African endemic that is restricted to the area of the Northern Cape Province that is west of the Great Escarpment, and to the area south of the Great Escarpment in the Western Cape, and the western section of the Eastern Cape Province. The 1990, 2014, and 2020 land use land cover (LULC) databases prepared for South Africa were used to determine the LULC categories that best describe suitable habitat for the birds using beta regressions and data on the exact locality of the birds from BirdLasser. The South African Bird Atlas Project (SABAP) reporting rates were used to determine the change in the relative abundance of the birds between the first and second SABAP. Beta regression models were compiled using the bird’s reporting rate and the total surface area, and three other landscape metrics, of the per pentad LULC categories considered to be suitable habitat for them. These models and the SABAP reporting rates revealed that Southern Black Korhaan is adversely affected by the loss of, especially, its fynbos habitat to crop agriculture. In 2020, the area of suitable habitat available to the bird was estimated to be 2,035,526 ha on terrain with a slope of ≤4°. Southern Black Korhaan remains “Vulnerable” to extinction because of the continued decline of >30% in the size of its population over three generations (31 years). The cumulative effects of habitat fragmentation and loss on Southern Black Korhaan and other threatened taxa must be mitigated by conserving and, where appropriate, rehabilitating suitable habitat (e.g. Gouritz Cluster Biosphere Reserve’s Corridors and Rehabilitation Project) in the protected areas, critical biodiversity areas, and ecosystem support areas identified in the provincial spatial conservation plans. Together these areas form a perforated landscape that ensures maximum connectivity between the remaining patches of indigenous habitat.

Forest raptor nest-site selection is mostly influenced by the quality of the habitat, food resources, and competition. Here, we identified common targets of trees selected as breeding sites and differences in selection traits, i.e. prey availability and intra- and interspecific competition, among Booted Eagle, Long-legged Buzzard, Black Kite, and Common Kestrel in a Mediterranean Cork Oak forest (private protected reserve of 25 km2). Using generalised linear mixed models we developed species-specific models describing nesting habitat selection. We tested the overlap in nesting habitat selection among species using environmental principal component analysis. The densities of forest raptor breeding pairs were high (3.1 pairs/km2) and the distance between occupied territories was short, strongly connected with food availability and competition. The results showed that all the species, with the exception of Common Kestrel, selected for nesting areas characterised by higher conspecific distance, highlighting the importance of conspecific competition. Booted Eagle and Black Kite selected areas with a high abundance of rabbits. The height of the nesting tree, the size and distance between surrounding trees, and the scrub cover were significant habitat characteristics for Booted Eagle and Long-legged Buzzard. Indeed, the environmental analyses showed a moderate nest site overlap between Black Kite and both Booted Eagle and Long-legged Buzzard, and a high overlap between Common Kestrel and both Booted Eagle and Long-legged Buzzard. Our study improves knowledge of the habitat requirements for nest selection and the potential competitive interactions between these raptor species in Mediterranean forests, and highlights the need for implementation of habitat management and conservation strategies.

Raptors play a unique role in ecosystem services and are regarded as effective indicators of ecosystem health. In recent years, varieties of anthropogenic factors have threatened the majority of raptor species worldwide. Nepal is considered a global hotspot for threatened and declining raptor species, but there is limited information on the direct human threats to the raptor populations living in the country. In this paper, we identify important anthropogenic threats to raptors in Nepal based on raptor mortality data collected by powerline surveys and from monitoring of GPS-tagged raptors, complete various reports, and social media. We found that powerlines, poisoning, and persecution, mainly shooting, are significant threats to raptors in Nepal that were largely overlooked previously. We report 54 electrocuted raptors affecting eight species, 310 poisoned raptors of 11 species, and five persecuted raptors of four species; among them vultures are the most affected (>88%). Based on our findings, to safeguard the future of Nepal’s raptors, we propose the retrofitting of power poles and the use of flight diverters on powerlines in the most affected areas to reduce raptor interactions with powerlines, as well as an effective conservation education programme to prevent the use of unintentional poisoning.

The Puerto Rican Nightjar Antrostomus noctitherus is an endemic Caprimulgid found in dry coastal and lower montane forests of south-western Puerto Rico. Information on the species (e.g. abundance, nesting biology) has been mostly restricted to forest reserves (i.e. Guánica Forest and Susúa Forest) with limited information available from private lands. We collected stand-level vegetation structure and geographical information from forest reserves and private lands to model habitat suitability and distribution for the Nightjar. Results of the stand-level model indicated forest type and midstorey vegetation density best predicted Nightjar habitat. Our spatial model predicted considerably more Nightjar habitat (17,819.64 ha) located outside protected areas than previously reported. Further, the model highlighted several localities of importance for the species across southern Puerto Rico, all located within private lands. We used a patch occupancy approach to assess regions identified by the landscape-level model as suitable for the Nightjar and documented the presence of the species in 32 of 55 sites, located in 12 of 18 municipalities across southern Puerto Rico. The protection and restoration of forest across the southern coast of Puerto Rico would help to ensure the long-term persistence of the Nightjar across a considerable portion of its range. Addressing habitat needs may be the single most effective mechanism to achieve recovery of the species.

The increase in the semi-wild Northern Bald Ibis Geronticus eremita population in Birecik, south-eastern Turkey motivated the Working Group of the Agreement on the Conservation of Africa-Eurasian Migratory Waterbirds (AEWA) to propose the establishment of a second semi-wild Northern Bald Ibis population in Turkey. This paper presents an assessment approach that identifies potential suitable breeding sites and foraging habitats within a large geographical area of approximately 380 × 60 km (23,000 km2) in south-eastern Turkey, which includes former breeding sites. This approach makes use of open-source and easily available geographical information. The structured approach is based on three key parameters, namely: (1) suitable breeding rocks; (2) suitable foraging habitats: (3) available water-bodies. This led to the identification of three potentially suitable areas around Derik and Yesilli in the Mardin province and around Yarbasi in the Sirnak province. The occurrence and spatial distribution of the three key parameters were mostly identified using Google Earth Pro 2021 within a radius of 10–20 km around the three sites. This procedure allowed an initial, cost-effective identification of potentially suitable areas, providing the basis for subsequent geographically focused comprehensive feasibility studies and on-the-ground risk assessment. However, geopolitical and pragmatic constraints may further affect and restrict a final selection of sites.

Records of the Nubian Bustard Nubotis nuba range across the drier northern component of the Sahel zone in Africa from Mauritania through Mali, Niger, and Chad to Sudan. Reports of significant hunting pressure have caused it to be treated as IUCN “Near Threatened” for almost 40 years, but information relating to distribution and population trends remains scattered, anecdotal, and unevaluated. All accessible evidence bearing on its conservation is therefore assembled and reviewed here. The lack of records from Mauritania since 1984, Mali since 1974, and Sudan since 1988 suggests that populations there may now be very small and perhaps entirely extinguished. Records from Niger and Chad remain many, thanks largely to the assiduous reporting of observations on the West African Bird DataBase (WABDaB) by researchers involved in ungulate conservation. The national nature reserves of Aïr and Ténéré (RNNAT) and Termit and Tin-Toumma (RNNTT) in Niger and the Ouadi Rimé–Ouadi Achim Faunal Reserve (RFOROA) in Chad emerge as vital to the long-term survival of the Nubian Bustard, given the accumulating evidence in both countries of (1) widespread habitat degradation and conversion, as human populations and their livestock expand in numbers and range in the Sahel, and (2) intensifying persecution, as highly mobile and well-armed local poachers plus Gulf state hunters gain increasing vehicular access to the remotest regions, depleting all huntable wildlife (a Sahel-wide bird study, 2011–2019, encountered just 16 bustards of four species – none Nubian – in 487 observation days). Populations of Nubian Bustard must now be greatly fragmented and depleted, with many entirely lost, so targeted programmes to minimise disturbance, persecution, and damage to habitat in the three key reserves (including the exclusion of powerlines) are urgently needed. Ultimately however the survival of this and other endemic Sahelian species can only be secured via a huge programme of ecologically and economically sustainable management practices.

Many Afro-Palearctic songbird migrants have declined, with conservation efforts mainly focused on the restoration of breeding habitat. However, pressures outside the breeding season might play a role. This includes the possibility that local relict populations no longer maintain the original phenotypic variation in migration patterns, with a loss of flexibility. The Great Reed Warbler Acrocephalus arundinaceus kept stable population levels in central and eastern Europe, but was almost extinct in the western part of the breeding range. In the Rhine delta the population declined from 10,000 individuals around 1950, to fewer than 100 at present. Here we document migratory timing, routes, and destinations of members of this remnant songbird population. It turned out that the remaining adults still showed high diversity in migratory phenotypes. This is even true in each of the two last tiny subpopulations in the Netherlands (of 50 and 15 pairs). So, even very small populations maintain the possible adaptive phenotypic variation, and with hindsight this justifies the breeding habitat restoration efforts currently underway.

Population size is one component of several criteria in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species (Red List). For these criteria, the quality of the population estimation can therefore have significant impact on the assessed status. To evaluate population estimate quality, we selected 473 species of land birds from the Americas considered by the Red List to be “Critically Endangered”, “Endangered”, or “Vulnerable” at the end of 2021, of which 414 (88%) had a population size estimate. For these species, we determined the age of the estimate and how the population estimate was derived, grouped into eight categories. For 87 species (18%) the population estimate was derived by sampling a small area and extrapolating to the entire range of the species; for these, the population size estimate depends on the estimate of range size. For the subset of 22 of these with complete data, we compared range size estimates obtained from maps published by IUCN with maps produced using the methods of Huang et al. (2021) to see how range map differences could affect population size estimates and therefore Red List status. Potentially half of these species (11 of 22) could change status using the new maps. More than one-third of the population size estimates (38%, 161 species with a date of population estimate) were made in 2000 or earlier. A majority of the species, 63% (300 of 473 species), do not have population size estimates made using a scientific sampling method, although the majority since 2010 have been made using a sampling method, reflecting an effort by Red List assessors to include more scientific information. We encourage the ornithological community to work to obtain current, high quality population size and range estimates to improve the quality of Red List status assessments.

The Seychelles Kestrel Falco araeus is an endemic species confined to the larger granitic islands in the Seychelles archipelago. It is classified as “Vulnerable” and became extinct on Praslin and La Digue islands in the 1970s, leading to an attempt of reintroduction in 1977. This reintroduction was not a success, with the last census reporting only four breeding pairs on Praslin Island. Studies on the Seychelles Kestrel are very limited and dated, and a lack of data on the biology and ecology of the species has made it difficult to make a thorough assessment of the cause of the current decline of the Praslin population. In order to determine the limiting factors on Praslin we investigated the following ecological parameters: nest-site availability, trophic availability, predatory pressure, and interspecific competition. Data were collected on Mahé and Praslin islands in three habitats (i.e. urban, suburban, and forest areas) and compared to determine if limiting factors differed among islands, habitats, and islands*habitat. We only found a significant difference in nest-site availability, with Praslin showing a marked lack of nesting cavities. Breeding pairs on Praslin are probably forced to nest in suboptimal sites. Indeed, the breeding success rate on Praslin is very low, and most of the nests there fail. The Seychelles Kestrel population on Praslin is in decline and cannot be sustained without human intervention. Such an intervention must take into account the ecological parameters highlighted in the present study.

Wetlands act as islands of high biodiversity within the ecological landscape and provide crucial ecosystem services to society. Anthropogenic activities are driving wetland degradation and it has become increasingly rare to find wetlands that do not show signs of biodiversity loss or alteration. The exacerbated loss of biodiversity in wetlands has a negative impact on the local economy and ecosystem services provided by these systems. We responded to the South African National Biodiversity Assessment (NBA) call to document wetland biodiversity against the backdrop of sustained wetland degradation in southern Africa. We monitored the soundscape of a high-elevation wetland in the Golden Gate Highlands National Park (GGHNP) from June 2019 to December 2020 across 24 localities using a rolling grid layout. We detected 35.9% of the avian species previously recorded from ad hoc sightings in the GGHNP of which 68.1% are wetland obligate species. We contributed an additional 10.2% new species records to the avian diversity of the GGHNP, including 24 species that are considered threatened by the International Union for Conservation of Nature (IUCN). Our remote monitoring technique enabled the first ever continuous monitoring using remote acoustic equipment for a high-elevation wetland in South Africa, thus providing a valuable contribution to the NBA call.