Structural vegetation damage and food limitation are important effects of major hurricanes, particularly for fruit/seed-eating, forest-dependent Caribbean birds with restricted distributions and small populations, such as the Bridled Quail-dove Geotrygon mystacea. Motivated by the lack of abundance estimates, corrected for detection probability, we conducted distance-sampling surveys inside and outside the Quill National Park each May in 2016-2019. Detection mode was the most important covariate, with others receiving no support from the data. Detectability of available single individuals and clusters of individuals within 60 m of transect centrelines averaged 0.957 ± 0.114 standard error for audio detections, 0.434 ± 0.052 for visual detections, and 0.693 ± 0.064 for detection modes combined. Availability averaged 0.475 ± 0.138 and the product of detectability and availability averaged 0.329 ± 0.098. Density averaged 1.459 ± 0.277 individuals ha-1 and population size averaged 642 ± 122 individuals in 440 ha. Density did not differ along and away from forest trails, but was higher inside than outside the park and at elevations within 201-400 m than 100-200 m and 401-600 m. Density declined by 76% after hurricanes Irma and Maria in 2017. We suggest that major hurricanes together with free-ranging livestock overgrazing degraded foraging habitats, limited food supply, and caused a population bottleneck. Our methodology can be implemented across the distribution range to assess population status and trends and evaluate the result of management actions at key conservation sites. Bridled Quail-dove populations probably were declining on most islands before the 2017 hurricanes and population status warrants revision.

Three subspecies of Island Thrush Turdus poliocephalus were historically found in New Caledonia. All these subspecies were considered extinct until 1978, when T. p. xanthopus was rediscovered on two small islands, Néba (∼ 3.5 km2) and Yandé (∼ 13 km2). On Néba, we estimated the population at 44–58 individuals. This Island Thrush population is dependent on the coastal forest, the richest habitat for invertebrates. However, the coastal forest habitat has been degraded in quality and extent. The Island Thrush forages in the litter by removing leaves with its bill. Fruits (diameter < 10 mm), picked from trees and swallowed whole, are also a significant component of its diet. Néba and Yandé are currently free of two nest predator species, the black rat Rattus rattus and the New Caledonian Crow Corvus moneduloides. On Néba, a low breeding success rate of 15.4% was found. To ensure conservation of these relict thrush populations, two actions at least should be implemented: setting up a biosecurity programme to keep islands free of black rats and increasing the area of coastal forest. The latter could be done by cutting down coconut trees in abandoned groves and planting tree species used by the Island Thrush to provide shade, fruits, good leaf litter, and nest support.

The Sooty Babbler Stachyris herberti, previously known from five specimens collected in Laos in 1920, was rediscovered in central Vietnam in July 1994. Fieldwork in Phong Nha Cultural and Historical Reserve located a population inhabiting lowland evergreen forest on limestone. The species was recorded on a number of occasions over several days and one female specimen was collected. The species appears to have highly specific ecological requirements and current human disturbance may have implications for its conservation at this site. A revision of its taxonomic position suggests its retention within the genus Stachyris.

In view of the continuing appropriation and conversion of natural land areas in North America for human uses, there is growing concern about the impacts of changing land use on terrestrial bird species. In order to promote conservation of critical remaining habitats for birds, Partners in Flight (PIF) initiated a project in 1997 in which bird conservation plans were prepared by members in each of 60 ecologically defined physiographical areas throughout the United States. Accurate, nationwide information on the location and extent of vegetative cover types, as well as lands under state and federal management, are critically important elements in the creation of effective bird conservation plans. The National Fish and Wildlife Foundation (NFWF) awarded a challenge grant to The Nature Conservancy's (TNC) Wings of the Americas Program to assist Partners in Flight in acquiring land cover data to serve as the foundation of the planning effort. Canon U.S.A., Inc. and the American Bird Conservancy also contributed support toward this goal. The Center for Advanced Spatial Technology at the University of Arkansas was contracted to produce the needed land cover maps and associated tabular products. Digital land cover databases created by the U.S. Forest Service, the U.S. Geological Survey, the Canada Centre for Remote Sensing, the University of California-Santa Barbara Department of Geography, and the U.S. Department of Transportation, Bureau of Transportation Statistics were used in this project. The final spatial products were produced during 1998–1999 and are described in this paper. This effort represents the first nationwide habitat mapping project in the United States aimed at supporting and enhancing conservation of terrestrial bird species.

Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species’ population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in seven areas within its Western European range (one in Portugal, four in Spain, and two in France). We found overall male-biased ASRs, as all the seven surveyed areas showed a male-biased ASR mean value. Five areas were below the threshold median value (female sex ratio = 0.4) considered to be consistent with an increased probability of extinction, according to earlier population viability analyses for the species. We also found a significant positive correlation between female ratio and the proportion of young individuals in the non-breeding flocks surveyed. Our results (strongly male-biased ASRs) support the hypothesis that the viability of Little Bustard populations in Western Europe is threatened by an excess of female mortality, something that should be quantified in the future, and emphasise the value of monitoring sex ratio as a population viability indicator in species where monitoring survival is difficult to achieve.

Studies of records of the Black-bodied Woodpecker Dryocopus schulzi through literature searches, communications with ornithologists, personal observations and data from museum specimens show that the distribution of the species is basically limited to xero-phytic chaco woodlands in western Paraguay, northern and central Argentina, and southern Bolivia. Its western limit is defined by the transition zone between the chaco and the semi-humid montane forest on the east Andean slopes of southern Bolivia and north-west Argentina; in the extreme south it extends into the dry deciduous woodlands n i the sierras of Córdoba and north-eastern San Luis. The taxonomic history of the species has been chequered; we present morphological and vocal differences from its closest relative that reaffirm its specific validity. It appears to have suffered an alarming decline over much of its former range in Argentina, and appears to survive only in two isolated population centres of significant importance, in Córdoba and adjacent San Luis and in the central part of the Paraguayan chaco. The main cause of its rarity is destruction of habitat for timber extraction and expansion of agriculture and cattle-raising.

El estudio de registros del Carpintero Negro Dryocopus schulzi mediante revision biblio-gráfica, comunicaciones de ornitólogos, observaciones personales e información adjunta a especímenes en museos, muestra que la distribución de la especie básicamente se circunscribe al bosque chaqueño de carácter xerófilo del oeste de Paraguay, norte y centro de Argentina y sur de Bolivia. Su extremo occidental alcanza la zona de transición entre el chaco y los bosques semihúmedos montanos en las sierras orientales andinas del sur de Bolivia y del noroeste argentino; en el extremo sur se extiende hasta los bosques secos decíduos de las sierras cordobesas y del noreste de San Luis. La historia taxonómica de l a especie ha sido confusa; las diferencias morfológicas y vocales que aquí se presentan y comparan con su pariente más próximo reafirman su validez específica. Parece haber sufrido una disminución preocupante en la mayor parte de su distribución original en Argentina, y quedan aparentemente tan solo un par de núcleos poblacionales aislados de cierta importancia, en Córdoba y zona adyacente de San Luis y en la zona central del chaco paraguayo. La principal causa responsable de su rarefacción se debe a la destrucción del hábitat por la explotación de los recursos madereros y a la creciente expansión de la frontera agrícola y ganadera.

Species baseline information is required for effective biodiversity conservation. Here we provide sound ecological data to support effective conservation of the Principe Scops-owl, Otus bikegila Melo, Freitas, Verbelen, Costa, Pereira, Fuchs, Sangster, Correia, de Lima & Crottini 2022, discovered in 2016. We mapped the observed and potential distribution, inferred habitat associations, estimated population size, and assessed the International Union for Conservation of Nature (IUCN) Red List category for this species. Surveys were carried out across Príncipe Island during the long and short dry seasons, recording owl presence in sampling points along transects. These data were used to model distribution, revealing that the Principe Scops-owl is restricted to 34.4 km2 in the south of the island, inside the Príncipe Obô Natural Park. Most records were in lower altitude native forest. Remoteness was the most important variable to explain presence at island level, followed by land use, which showed that the species is restricted to forest, clearly depending on native forest. Distance sampling using different models suggested a population density ranging between 33.4 individuals/km2 (95% CI: 23.6–47.2) and 46.4 individuals/km2 (95% CI: 29.3–73.6), which extrapolates to an estimated population size ranging from 1,149 individuals (95% CI: 813–1,623) to 1,597 individuals (95% CI: 1,007–2,533). We propose that the species is classified as “Critically Endangered” due to the small extent of occurrence, coupled with occurrence in a single location and inferred continuing declines in the extent of occurrence, area of occupancy, number of mature individuals and area, extent, and quality of habitat. Effective conservation of the Principe Scops-owl requires regular monitoring and further studies focusing on reproduction and potential nest predation by introduced mammals. Widespread support for the conservation of the Natural Park is vital to ensure the protection of this species and the endemic-rich native forests of Príncipe on which it depends.

Plastic pollution affects marine ecosystems worldwide and poses risks for seabirds. Most recorded impacts on organisms are negative but, in some cases, the constructive use of plastic fragments or objects by birds has also been recorded. Small blue and green plastic fragments are found scattered among nests in a large (c.500,000 pairs) Sooty Tern Onychoprion fuscatus nesting colony on Bird Island, Seychelles. We investigated whether the fragments were being imported by the birds, and if so whether import was accidental or intentional. We found that Sooty Terns were the only seabird species to have plastic fragments in their nesting area and import of fragments varied seasonally and spatially. Throughout the colony, plastic fragments were imported during egg-laying, incubation, and chick-rearing, but import declined as chicks began to fledge. A part of the colony where all eggs were harvested for human consumption received more fragments than among undisturbed nests. We failed to find evidence of ingestion and excretion of fragments and suggest other avenues for investigation.

White-necked Picathartes Picathartes gymnocephalus is a globally ‘Vulnerable’ bird endemic to the highly threatened Upper Guinea forests in West Africa. In an environment under a high level of threat, the high breeding site fidelity (or breeding site persistence) of this species enables long term monitoring of colony site occupancy, colony size and other breeding parameters, which provide multiple indicators of population status. We surveyed known colony sites and searched for new sites in three recent breeding seasons in order to assess the current population status in the most important part of their range in Sierra Leone, the Gola Forest. We found 157 active nests at 40 colonies, equating to at least 314 adult birds. Less than half of the known colonies were protected by the Gola Forest Reserve. Colonies outside the reserve tended to be confined to larger rocks and subject to disturbance from human activities in close proximity, but did not have fewer active nests in them. Colonies outside the reserve were also more likely to be inactive in a given year whereas all colonies inside the reserve were active in every survey year. A predictive distribution model indicated that the survey region could have as many as 234 nests equating to at least 468 breeding birds. There was no evidence that mean colony size had declined since surveys undertaken in the 1980s and 1990s but it was not possible to compare colony abandonment rates inside and outside the reserve over that time period. Clutch and brood sizes were similar in each year, though brood size appeared slightly lower in the third survey year possibly because of a slightly later survey date. Mean clutch and brood sizes reported during the study period were similar to those found in the 1980s and 1990s. We conclude that the population of White-necked Picathartes in the Gola Forest area has been relatively stable over the last two decades, reflecting both the efficacy of protection afforded by the Gola Forest Reserve and presumably low pressure to farm new areas in the nearby community forest. However, regular monitoring of colonies both inside and outside the reserve is required to detect any systematic impact on the birds as pressure for land increases.

Since its rediscovery in 1998, two major threats have been mentioned for the enigmatic Austral Rail Rallus antarcticus: cattle management by burning grass and rushes and predation by American mink Neovison vison. Added to the lack of a protocol to monitor this secretive bird, ever-growing threats make it necessary to study its global situation in depth to take accurate and urgent management decisions. We firstly studied how threats to the Austral Rail currently impact their occupancy and relative density (RD) at a wetland scale and habitat features associated with its presence at survey site scale inside wetlands in Santa Cruz province, Argentina. We additionally developed a monitoring protocol to detect the rail effectively and promptly by studying responses to playback with two different vocalisations at different times of the day and season. Both threats evaluated were negatively related to occupancy and RD of the Austral Rail, especially mink presence appearing to have an additive effect. We propose American mink control as crucial for Austral Rail conservation, while it would also be necessary to conserve a portion of wetlands exempt from burning and cattle presence. At survey sites, its presence was positively related with c.1–1.5 m tall rushes, whilst rails avoided low- density rush areas that resulted after management of rushes with fire to create pasture. To detect rails, both vocalisations can be confidently used at any time of the day and season. The poor knowledge about species ecology, mismanagement of vegetation in wetlands, expansion of American mink in Patagonia, construction on two dams in the Santa Cruz river basin, added to the already modified humidity conditions due to global climate change, force us to suggest that the Austral Rail should be considered as globally ‘Endangered’ (EN), to ensure the consideration of the species in management decisions.

Conservationists often find it difficult to assess long-term population change in a species when the only data available are from disparate sources. This is especially the case when a range of survey methodologies and reporting units have been utilised and the results have been published in the ‘grey’ literature. Although the production of a cohesive assessment of change may be a daunting task, in such circumstances, a sound assessment of change is often possible. We illustrate this by considering the decline of the Twite Carduelis flavirostris in England. Whilst there is evidence of decline, it is widely dispersed and the losses have yet to be formally documented. To assess longer-term change, we reviewed information available in county avifaunas and historical accounts of the status of the species throughout its former English range. Twite now only breed regularly in six of their 12 historical range counties, and in all of these six, the birds have declined markedly in abundance. We collated and analysed data drawn from a diverse range of surveys and county bird reports to assess more recent change and assessed contemporary distribution and abundance during our own surveys of breeding colonies in the South Pennines, an area supporting the last known nesting colonies in England. Combined, the data clearly indicate that the range and numbers of breeding Twite have declined considerably since the 1970s. Recent re-surveys in the South Pennines indicate a significant range contraction, with a loss of Twite from 83% of 1-km grid squares found occupied during a 1990 survey. A detailed resurvey of historical breeding sites in east Lancashire revealed a similar pattern, with 77% of sites having lost their colonies over the last four decades. We also constructed an index of change in numbers on the east and south-east coastal wintering grounds used by English breeding birds and this shows that numbers have severely declined since the 1970s, mirroring change on the breeding grounds.

This paper documents the catastrophic decline of the ‘Critically Endangered’ Fatu Hiva Monarch Pomarea whitneyi since 2000 and presents population dynamics and conservation actions for the species between 2008 and 2017. The Fatu Hiva Monarch conservation programme has prevented the extinction of the species thus far. However, after an initial increase in the population size within the management area between 2008 and 2012, recruitment subsequently declined. Improvements in the method of trapping to control cats in 2016 and 2017 coincided with encouraging results in terms of juvenile monarch survival rates, although two adult birds disappeared during the same period. The initial hypothesis, that the population would recover once the main threat, black (or ship) rat Rates Rattus predation, was effectively controlled in the breeding territories, has not proved to be correct. An alternative hypothesis assumes that cat predation, mainly on young birds, is limiting monarch recovery. Control of feral cats has been undertaken since 2010, but the implementation of a new trapping method (leg-hold traps) combined with a significant increase in cat trapping effort, has coincided with an increase in the number of cats culled, as well as monarch post-fledging survival in 2016 and 2017. For the first time in the project, no mortality has been observed for monarch chicks, fledged juveniles or immature birds. If this alternative hypothesis holds, we would expect to recruit young birds into the monarch population in the next year or two. First, this will reduce the likelihood that the Fatu Hiva Monarch will become extinct and second, provide a source population to either repopulate the island following the eradication of rats and cats or to translocate birds to a rat and cat free island.

The ‘Endangered’ Cape Vulture Gyps coprotheres has been monitored across its range for decades through disparate studies varying in geographical scope and length. Yet, no long-term, range-wide survey exists for the species. Coordinated monitoring across the range of the Cape Vulture would be logistically challenging but provide a holistic view of population dynamics in this long-lived species that forages across much of southern Africa. Here, we report breeding pair counts from seven colonies in the Cape Vulture’s north-eastern breeding region from 2010 to 2019. We used state-space models to assess population growth across time. Manutsa, Soutpansberg, and Nooitgedacht colonies increased significantly over the study period, with three other colonies having positive estimates of population growth, but 95% credible intervals overlapped zero. The smallest colony at Moletjie is declining toward extirpation; only one breeding pair remained in 2019. Our results suggest the north-eastern population has been stable or increasing since 2010 with our 2019 surveys counting 2,241 breeding pairs across all sites. Indeed, there is an 89% chance that the population across the colonies we monitored increased from 2010 to 2019. Coordinated, range-wide, full-cycle monitoring is needed to thoroughly assess conservation status and efficacy of conservation actions taken for this endangered species.

We report on what appear to be increasing predation events on nesting Thick-billed Parrots Rhychopsitta pachyrhyncha. Thick-billed Parrots are classified as ‘Endangered’ and their seasonal breeding range is restricted to increasingly fragmented and degraded high elevation mixed conifer forest habitat within the Sierra Madre Occidental region of north-western Mexico. Predation of established breeding pairs has recently contributed to the ongoing decline of Thick-billed Parrot populations by removing mature birds with high reproductive value, which has associated consequences for future recruitment. We observed increasing predation events on nesting Thick-billed Parrots by bobcats Lynx rufus accompanied by kittens throughout the 2018–2019 breeding seasons, and we speculate that recent reductions in bobcat habitat have pushed them into new ranges where they are supplementing their diet with nontraditional prey items.

An evaluation of the relative abundance of the Black Catbird Melanoptila glabrirostris was undertaken on Caye Caulker, an offshore island along the barrier reef of Belize, Central America. Although the species is locally abundant in part of the Sian Kaàn Biosphere Reserve in Mexico, the species is facing habitat fragmentation and loss due to development, both along the Mexican coastal areas and on the island habitats in Belize. The Caye Caulker population appears to be the largest in Belize. Transects of fixed radius point counts resulted in 15.5% and mist-netting resulted in 22.4% of all birds recorded being Black Catbirds. The Neotropical migrant Grey Catbird Dumetella carolinensis apparently shares the same habitat on Caye Caulker and comprised 11.2% of all birds netted. The netted Black Catbirds were noted to have substantial fat deposits. The habitat on Caye Caulker is facing probable fragmentation from recent accelerated land speculation and development of an airstrip.

The Hainan Hill-partridge Arborophila ardens is endemic to the island of Hainan, which lies off the south coast of China. Distinct subspecies of the Silver Pheasant Lophura nyethemera xvhiteheadi and Grey Peacock-pheasant Polyplectron bicalcaratum katsumatae are also endemic to the island. All three taxa are considered endangered and are very poorly known in the wild. Surveys of remaining patches of forest were undertaken between 1987 and 1994 during which local people were interviewed and some forest areas were visited. The hill-partridge was confirmed from three blocks of forest and reported from a further four. The Silver Pheasant was found in six areas of forest and probably occurs in all remaining patches of well-developed secondary and primary forest. The Grey Peacock-pheasant was recorded in five forests and reported from a further four. The hill-partridge was more restricted in its habitat use than the other two species, the latter using well-developed secondary forest in addition to primary forests. Provisional density estimates made at Ba Wang Ling National Nature Reserve were 6–8 Hainan Hill-partridges/km2, 7.5 Silver Pheasants/km2 and 3.75 Grey Peacock-pheasants/km2.

South-west China, particularly between the Himalayas and the Beibu Gulf, constitutes an important corridor for migratory raptors along the East-Asian continental flyway. However, a lack of ornithological assessment and the common practice of illegal hunting in this region emphasize the need for research and conservation actions. To investigate the ecology of migration and scale of persecution, we launched one of the first citizen-science projects in mainland China to record southward-migrating raptors and hunting gunshots from 2015 to 2019 on Guantouling, a well-known raptor site in South-west China. A total of 42,891 raptors were recorded, belonging to 30 diurnal raptor species. Grey-faced Buzzard Butastur indicus, Oriental Honey Buzzard Pernis ptilorhynchus and Amur Falcon Falco amurensis were the three most abundant species recorded. The bulk of Grey-faced Buzzard and Amur Falcon migrated through Guantouling from mid-October till early November, while Oriental Honey Buzzard migrated throughout October and early November. Precipitation slowed down migration significantly while increasing cloud cover was favoured by the three most abundant species. We found hunting mostly occurred in the afternoon, coinciding with an increasing number of Oriental Honey Buzzard, which may become a major victim of hunting. It is thus suggested to prioritize peak raptor migration period for law enforcement actions, especially on cloudy days and after passage of cold fronts, when Oriental Honey Buzzards and other species are likely to migrate. The annual counting scheme on Guantouling is not only an ecological survey, but also an effective way of engaging the public to counter raptor persecution.

The Rota White-eye, Zosterops rotensis, is a critically endangered species endemic to the island of Rota, in the Mariana Islands, western Micronesia. There has been a dramatic decline in both its population size and range over the past few decades. The population, estimated at approximately 1,000 individuals in 1999, is found exclusively in 300 ha of mature limestone forest, though nearby areas of mature limestone forest remain unoccupied. We compared the bird community, vegetation characteristics and foliage-invertebrate density in forest plot pairs with known high and low densities of Rota White-eyes. Discriminant function analysis suggested that certain vegetation characteristics were best at predicting whether a plot was high-density or low-density. High-density plots had more stems with 20–50 cm DBH, more foliage intercepts at 3–9 m, more epiphytes, greater total canopy cover and fewer overall plant species. This information is essential for the protection of the current habitat of the Rota White-eye and for future efforts in the protection and management of this species.

The diet patterns and trophic relationships are poorly understood for most tropical owl species. We used stable isotopes of carbon (δ13C) and nitrogen (δ15N) in 24 feather samples of the rare, endemic, and ‘Near Threatened’ Bearded Screech-owl Megascops barbarus to determine the trophic level of their prey and evaluate whether diet patterns vary (1) among individuals, (2) spatially along the species's range in the highlands of Chiapas, Mexico, and (3) temporally during the short- and long-term. Our results indicated that there was diet variation among individuals during the period of feather growth and there was a high positive correlation between stable isotopes in body and rectrices. The stable isotopes showed significant temporal differences in δ15N signature values, but not in δ13C values, with no obviously interpretable temporal pattern. Spatially, values of δ13C and δ15N did not vary across all nine sampled locations. The observed lower δ13C values suggested that this owl lives in humid forests. More long-term studies and spatial dietary and prey analysis will be necessary to increase our understanding of how habitat conditions determine the distribution, abundance and quality of food for the Bearded Screech-owl.

This research evaluated the nesting habitat, nest-site preferences, and nest architecture of the critically endangered White-bellied Heron Ardea insignis in Bhutan. There are fewer than 60 wild birds left in the world, distributed in Bhutan, India, and Myanmar with fewer than five active breeding pairs in Bhutan. From 2003 to 2018, 20 successful and two unsuccessful nests were located from which at least 76 juveniles were expected to have fledged. The population in Bhutan has remained at 22–30 individuals for the last decade. Site-specific data were collected from 22 nests, and additional vegetation and environmental data were collected from 14 nests and random sites. We used 20-m diameter circular plots to evaluate the site preferences. Ground vegetation, litter and rock cover were evaluated using four 1-m2 quadrats in both nest and random sites. Nesting habitat was analysed to compare characteristics of nesting sites to random sites. Our results suggest that the White-bellied Heron builds a simple platform nest within average distance of 74 m from water bodies on the tallest isolated trees at an average height of 18.3 m on an elevated site with a clear overview of surroundings and are sensitive to even slight disturbance. Our results also suggest that the bird has a preference for an east-facing aspect at an average slope of approximately 40° between the altitudes of 400–1,450 m. Our observations also suggest that the bird has abandoned all nesting sites used prior to 2015, and the frequency of nest re-use has decreased. Protecting each nest site from hazards, avoiding disturbance, maintaining safe feeding habitats and flight routes are essential to ensure continued breeding in current sites and survival of this population. Further research to better understand the habitat requirements for the White-bellied Heron is vital.