Recently recognised as specifically distinct, the Príncipe Thrush Turdus xanthorhynchus is endemic to the island of Príncipe in the Gulf of Guinea, West Africa. Formerly treated as conspecific with the more abundant T. olivaceofuscus from the nearby island of São Tomé, the Príncipe Thrush is considered rare and likely to be restricted to primary rainforest. A 2007 survey of Príncipe comprising 177 point transect locations covering 13 sites under different land uses (six in primary forest, three in secondary forest and four in plantations) encountered 18 individuals. Thrushes were found only in primary rainforest, where overall densities were 0.10 birds ha−1, equating to a population size of 435 individuals (95% confidence intervals: 208–913). We adjusted this estimate to take into account the fact that the highest density (0.22 birds ha−1) only occurred above 600 m, giving a final estimated population size of only 364 birds (95% confidence intervals: 186–887). In light of evidence of recent declines, possibly driven by hunting pressure, in the number of mature individuals and the limited area of occurrence of the species, the IUCN Red List category for the Príncipe Thrush should be ‘Critically Endangered’ under both criteria B1a+b(iii and v) and C2a(ii). The recent designation of the primary forests of southern Príncipe as a protected area (Parque Natural d’Obô do Príncipe) provides an opportunity for the conservation of this newly described species, which we recommend is used as a flagship for the forests as a whole.

Peruvian Terns Sternula lorata breed in the sand desert plains of the coast of Perú and northern Chile. Because of their long-term population decline, Peruvian Tern is categorized as ‘Endangered’ on the IUCN Red List. The observations that formed the basis for that decision were made in the 1970s and 1990s. In this study, we compile information on distribution, numbers, habitat use and threats of Peruvian Terns that has become available between 2003 and 2008 from 14 localities on the Peruvian coast. Peruvian Tern sites are located between the mangroves of San Pedro de Vice in the north (5o31’S) and the wetlands of Ite in the south (17o56’S). From the 14 locations, five are reported for first time: Virrilá, Eten, Huanchaco, isla Mazorca and Ite. There were only four active breeding sites: Pacasmayo, Paraíso, Pampa Lechuzas and Tres Hermanas-Yanyarina; however, some localities were visited outside the breeding season and should be surveyed between October and February to search for nests. The presence of 283 individuals was confirmed at the 14 sites in an area of approximately 1,388 ha (which represents only 0.35% of the total suitable area for nesting along the Peruvian coast). Thus, the number of Peruvian Terns in Perú should increase with systematic surveys. Here for the first time we report the importance of wetlands for the Peruvian Terns (43% of the sightings occurred in this habitat). Wetlands can offer optimal conditions for feeding, but the cost of using them is becoming higher with a sharp increase of human expansion into coastal areas and urban development around wetlands. We identified the following threats affecting Peruvian Terns on their feeding and breeding grounds: 1) recreational activities; 2) off-road driving by fishermen and tourists; 3) wetland pollution and water use for irrigation; 4) conversion of desert plains to agricultural land; 5) management of wetland water levels; 6) presence of feral cats and dogs, and 7) oil exploration on the desert plains. These adverse factors can be eradicated by the protection of tern sites and public awareness and education. Conservation actions, monitoring and research priorities are suggested.

The Orange-breasted Falcon Falco deiroleucus, among the world's most poorly known falcons, is sparsely distributed in Neotropical forests from south-east Mexico or Guatemala to Paraguay and northern Argentina. Details of distribution and population size are poorly known throughout the species's range. From 1992 to 1997 we studied this species at 19 nest sites in Guatemala and Belize. Occupancy and productivity rates remained stable for this northernmost population over this six-year period. Sparse data on historical distribution preclude a full assessment of possible changes in population status in the Mesoamerican portion of the species's range. Today the species appears restricted to forested areas in conjunction with large nesting cliffs. No breeding record is known for any Mesoamerican nation except Belize and Guatemala. Mean number of fledglings per successful nesting was significantly higher in areas of predominantly forested mosaic habitat (2.11, n = 18) than at sites with uninterrupted mature forest (1.36, n = 11); proportion of sites occupied and of pairs fledging young did not differ between these two habitats. Based on historical and current distribution records and distribution of potential nesting habitat, we conclude that the Guatemala/Belize opulation of Orange-breasted Falcons is disjunct from the species's main range in South America, is perhaps the only local population (at best one of a small number) in Mesoamerica, and is tightly linked to the existence of suitable nesting cliffs combined with large forested areas.

The Critically Endangered Oriental White-backed Vulture Gyps bengalensis has declined across most of its range by over 95% since the mid-1990s. The primary cause of the decline and an ongoing threat is the ingestion by vultures of livestock carcasses containing residues of non-steroidal anti-inflammatory drugs, principally diclofenac. Recent surveys in Pakistan during 2010 and 2011 revealed very few vultures or nests, particularly of White-backed Vultures. From 2011 in the Tharparkar District of Sindh Province we monitored a colony of Oriental White-backed Vultures. Between 2011 and 2014 the number of active nests in this colony increased from 11 to 34 while nest density decreased from 13.7 to 9.2 nests km-2, suggesting that the colony is expanding. We conclude that the rate of increase is being subsidised by immigration, as the population demographics do not support the observed rate of increase in nests. We present the first analysis of spatial breeding dynamics for the Oriental White-backed Vulture and describe how a clustered pattern of nest trees in colonies supports a highly clustered pattern of nests. The spatial pattern of nests relies on both the distribution of trees and the ability of trees to support more than one nest. These results highlight that the preservation of larger nest trees and the sustainable management of timber resources are essential components for the conservation management of this species. We emphasise the high importance of this colony and a nearby Long-billed Vulture Gyps indicus colony in this area of Pakistan. Recommended conservation management actions include the continuation of a Vulture Safe Zone established in 2012, measuring breeding success, assessing dispersal and determining the impact of mortality on these populations.

Prolonged declines in the number of Steller’s Eider Polysticta stelleri wintering in Europe have raised concerns about the conservation status of the Western Palearctic population. Coordinated helicopter surveys of all known wintering areas in Norway and Russia and ground counts in the Baltic in 2009 found c.27,000 Steller’s Eiders, similar to numbers found during the last such survey in the mid-1990s. However, around 85% of the population now winters in Russia compared to 30–50% then. The reasons for this rapid shift in distribution are unknown but are likely linked to climate change. The continuing small population size, specialist feeding and restricted distribution of Steller’s Eider necessitate continued survey and research to track population changes and provide evidence for conservation management actions to safeguard the species.

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.

Following the catastrophic decline in populations of three species of South Asian Gyps vultures, we conducted a study to explore socio-economic variables that could facilitate conservation efforts. A questionnaire survey was carried out in 103 randomly selected households in the Rampur valley, one of the Important Bird Areas of Nepal, during 2004. Among respondents, 38% were female, 62% male, 28% illiterate and 72% literate. Households belonged to three ethno-religious groups (Hindu castes, ethnic groups and Muslim) and 96% of households had some parcels of registered land to farm. About 90% of households reared one or more types of livestock while the mean Livestock Size Unit was 3.32 per household. Livestock diseases and ailments were common and usually treated with diclofenac. Livestock carcass disposal practices were favourable to vultures because 60% of households dumped carcasses in open fields. Diclofenac is lethal to vultures; 3% of diclofenac-contaminated carcasses were available annually. The majority (78%) of respondents had favourable attitudes towards the concept of vulture conservation. Diclofenac contamination and the destruction of nesting habitat were two major threats to vultures. Ensuring healthy food through economic incentives, inculcating new values through environmental education and soliciting popular participation for habitat conservation are recommended.

Most research on cockatoos Cacatua outside Australia has focused on species that figure significantly in the pet trade. Here, we examine the status of Blue-eyed Cockatoo Cacatua ophthalmica, an extremely poorly known species endemic to the island of New Britain, in three lowland forest types: primary forest, forest that had been commercially logged of selected large trees in the previous eight years, and forest gardens (small-scale mixed agroforests or “homegardens” tended by indigenous people). During fieldwork at two lowland study sites on New Britain between December 1998 and April 1999, groups of C. ophthalmica were recorded in all forest types (maximum group size = 40), but the species was largely absent from non-forested areas. Estimated cockatoo density in selectively logged forest (64 individuals per km2) was similar to that in primary forest but densities in forest gardens at both sites (6 and 28 per km2) were considerably lower than those in primary forest (27 and 73 per km2). Most active nests found were in large trees in primary forest and the paucity of nests in logged forest, and particularly in forest gardens, is cause for concern given ongoing forest alteration on the island. While we predict that the Blue-eyed Cockatoo population on New Britain is declining, the species remains numerous and the current low levels of trapping and the large area of suitable forest remaining on the island indicate that the taxon is currently of “Least Concern”. In a wider context, C. ophthalmica is considerably more common than most of the traded cockatoos, but the tendency for cockatoo densities to be highest in primary forest, intermediate in human-altered forests and lowest in non-forest areas holds for traded and untraded species alike.

Large declines of farmland bird species have been observed in the lowlands of Western Europe, whereas important populations of some of these species have survived in parts of Eastern and Southern Europe and in small areas within Western Europe, e.g. in parts of the Alps. However, such extant hotspots of farmland biodiversity are at risk: The economic and technical developments threaten to erode biodiversity in existing hotspots, potentially repeating the collapse previously observed in Western Europe. We here present changes in the abundance of farmland birds in the Engadin in the Swiss Alps. Farmland birds such as Whinchat Saxicola rubetra and Skylark Alauda arvensis were still numerous in 1987/1988 when we first censused the area. During our second census period in 2009/2010, we noticed strong declines of such open country species, while several hedge and tree breeders as well as some species preferring warmer climate increased. We observed a good correlation between the change in the vegetation and in the birds. Both these changes were especially pronounced in areas with a recent agricultural improvement project. Thus, we believe that the change in farmland practices, which affected our mountainous study area much later than the lowlands, and possibly climate change, have led to a profound change in the regional avifauna. Using our data as a case study, we argue that similar, and similarly fast, changes may be on-going or imminent in many other areas with extant important populations of farmland species such as Whinchat and Skylark. Thus, our data add to the repeatedly declared urgency to adjust the advancement of agricultural subsidy systems to better accommodate biodiversity considerations, both in depauperated areas as well as in extant hotspots.

The Dalmatian Pelican Pelecanus crispus is a globally threatened species with three distinct populations, the smallest of which is the almost extinct eastern race with an estimated population size of 50 birds breeding in Mongolia and migrating to south-east China during the winter. We analysed recent survey information and published records to construct a picture of the annual life cycle of the Dalmatian Pelican and how it has changed over the years. We were able to obtain a total of 196 records from 82 sites in China and Mongolia dating back to 1862. Seasonal information was available for 168 records. The pelicans breed in western Mongolia and migrate in a south-easterly direction to the Bo Sea and then southwards along the coasts of Shandong and Jiangsu to the wintering area in south-east China. Return migration to the breeding grounds follows the same general path. There is some evidence that part of the population uses an inland migration route linking the wetlands along the Yellow and Huai Rivers and the middle reaches of the Yangtze River; this route was probably more important historically. The pelicans are encountering serious problems at all stages of their annual life cycle: destruction of nesting habitat and hunting in the breeding area, loss of important wetland habitats along the inland migration routes, and land claim, human disturbance and overexploitation of fisheries resources on the coast. It is highly desirable that a simultaneous count be conducted of the key wintering sites so that an accurate population estimate can be obtained. Use of satellite telemetry would provide very useful information on migration strategies and home ranges in the wintering grounds, and assist greatly in identifying key habitats for conservation action at different stages of the annual life cycle.

The Brown-banded Antpitta was last recorded in the Central Andes of Colombia in 1942 but a population of the species has been rediscovered in the Ucumarí Regional Park.

Grallaria milleri era una especie conocida de solo diez especímenes colectados en dos localidades de la vertiente occidental de la Cordillera Central de Colombia. Nueve de los especímenes fueron colectados en la cuenca del Río Quindío, a elevaciones entre 2, 745 y 3,140 m, en 1911 y 1942. El décimo especimen fue colectado en 1918, a 3 km de la ciudad de Manizales. Durante trabajo ornitológico realizado en el Parque Regional Ucumarí desde 1994, individuos de esta especie han sido capturados en redes y observados, lo cual revela la presencia de una población en este sitio intermedio entre las dos localidades originales. El Parque Ucumarí tiene 4,240 ha y protege la cuenca alta del Río Otún entre 1,800 y 2,600 m. G. milleri ha sido registrada solamente en un estrecho rango entre 2,400 y 2,600 m, en donde se han contado 93 individuos a lo largo de 6.3 km de transectos en tres tipos de hábitat: rastrojos de regenración temprana, plantaciones de aliso (Alnus acuminata) y bosques de regeneratión de treinta años. En esta localidad G. milleri es simpátrica con otras cuatro especies de Grallaria (squamigera, nuchalis, ruficapilla y rufocinerea) y con Grallaricula nana, por lo cual Ucumarí es un sitio de gran interés para la conservatión de este grupo de aves neotropicales.

Call counts of Satyr Tragopan Tragopan satyra were conducted in the Singhalila National Park, Darjeeling, India, for three years (1995–1997). Twenty-eight groups of calling birds were recorded in 1995, 19 in 1996 and 24 in 1997 with mean density estimates (groups/km2) of 6.19/km2, 4.52/km2 and 5.46/km2 respectively. During the three years, the number of calling groups varied only on one trail. Birds called early (04h45–05h00) and the calling frequency varied from 33% to 88%. Calling peaked in April and there were significant differences in the number of groups calling in April and May in 1995 and 1996. Adverse weather conditions and wind affected calling and the audibility of calls. During spring, the Satyr Tragopan was found to be associated with both open and closed habitats. The main possible threats to this species were grazing and tree lopping. Despite some shortcomings this survey method appears to be most suitable for monitoring Satyr Tragopan.

The Olrog’s Gull Larus atlanticus is an endemic and threatened species of the south-western Atlantic. Little is known about its movements during the non-breeding period. The objective of this study was to analyse the migration of the species by tracking adults from Bahía San Blas (Buenos Aires province, Argentina) with geolocators and using information of sightings of ringed gulls. Differences between males and females were evaluated using tracking data and ringed data were used to determine age differences. A single core area (kernel 50%) from 21 tracked birds was identified. This area included the study colony and also other breeding colonies located up to 300 km to the north. The range area (kernel 95%) included coastal areas up to 1,000 km from the colony. All sightings of ringed gulls (n = 41) occurred north of the breeding colony, however 12 adult individuals were sighted during the winter in its breeding grounds. Our results suggest the occurrence of partial migration behavior in Olrog’s Gull. The migration pattern reported here implies than during the non-breeding season, breeding and wintering areas away from the nesting grounds should be considered as one system in the design of conservation strategies for this regionally threatened gull.

Effective conservation measures for any bird species across their distribution ranges require detailed knowledge of landscape-specific differences in habitat associations. The Ortolan Bunting Emberiza hortulana is a farmland bird species, which experienced massive population declines during the recent decades and has become a conservation priority in many European countries. Thus, identification of the key habitat features is an important prerequisite for the conservation of the species. Here we investigate habitat associations of the Ortolan Bunting for the remaining breeding population of the species in the Czech Republic. This population is remarkable by its distribution in two markedly different environments – farmland and post-mining landscapes. The main objectives of this study were to identify habitat features associated with Ortolan Bunting occurrence within the two contrasting landscapes and at two spatial scales. Our results reveal a high degree of habitat plasticity by Ortolan Buntings in the Czech Republic which was revealed by the landscape- and scale- specific habitat associations. Habitat heterogeneity, in terms of compositional and configurational diversity, and the cover of bare ground were the most important predictors of Ortolan Bunting occurrence in both landscape types. In farmland, the species occurrence was positively associated with shrub and woody vegetation, poppy fields and set-asides, and negatively associated with grasslands, gardens/orchards, seedlings and urban habitats. In the post-mining landscape, the cover of herb vegetation and greater slope steepness and terrain ruggedness were most important habitat features. Ortolan Buntings in the post-mining landscape appear to avoid patches with a higher cover of shrub and woody vegetation, forests, seedlings and urban areas. We propose that conservation measures for Ortolan Buntings should focus on enhancing farmland habitat heterogeneity, but also on regulating the rate of succession in disturbed environments, such as post-mining landscapes.

Wind power, as an alternative to fossil fuels, is increasingly common, and is expanding worldwide. Wind farms cause mortality of flying animals through collision with moving rotor blades, and from electrocution on associated power lines. Avian mortality rates have been estimated from birds collected under turbines over varying time intervals. However, without adequate and frequent monitoring, dead birds may be removed by scavengers and thus cause an underestimation of fatalities. In this paper, we tested experimentally for possible errors arising in avian mortality caused by the removal of carcasses by scavengers. At two different wind farms and associated power lines in southern Spain, we placed pigeon and quail carcasses to determine their disappearance rate. All dead pigeons were radio-tagged to estimate distances taken by scavengers. We found significant differences in carcass disappearance rates of pigeons and quails, and between wind farms and power lines but not between habitats. All quails and 45% of pigeon carcasses had disappeared by the third and fourteenth day, respectively. Less than half (40%) of the carcasses were found < 100 m from where they were deposited. While scavenging losses may vary according to the location of the wind farm or power line, here we propose a method to estimate correctly the number of fatalities at any wind farm and power line. Using this method, we can improve our understanding of the real impact of wind structures on adjacent bird communities, and adopt appropriate measures to ensure their conservation.

The Near-threatened Orinoco Goose Neochen jubata is a poorly known South American sheldgoose with a declining population and range distribution. In this study, we surveyed the Orinoco Goose population along the middle reaches of the Rio Juruá, western Brazilian Amazonia, and its first-order tributaries. We quantified the seasonal abundance of geese, pinpointed their approximate breeding season, and examined their habitat associations and the potential effects of human activities on their abundance. Hunting by local villagers was also monitored to assess the offtake rate of this species. Orinoco Goose occurrence in the region was highly seasonal and restricted to the dry season. We estimated a mean dry-season encounter rate of 7.18 ± 2.45 adult individuals per 4-km section along this river. Immature individuals were seen along the river margins from August to December. The species showed a strong preference for sandy beaches and was primarily restricted to the main river channel, with few individuals occurring along tributaries. The encounter rate of this species was also significantly related to fluvial distance from the municipal urban centre and to the level of protection from hunting. Hunting of Orinoco Goose was reported in 12 of the 26 villages monitored. The seasonal appearance of the Orinoco Goose in the region indicates that this is a migratory population. Our study indicates that strict protection of the river margins, and sandy beaches in particular, along the main river channel is likely to be positive for the conservation of this species along the Rio Juruá. However, further knowledge of migration routes is critical for effective protection of both breeding and non-breeding populations.

Globally, vultures are one of the most threatened of all groups of birds. European vulture populations are benefited by several anthropogenic food sources such as landfills. Current European Union directives aim to decrease the amount of organic matter dumped in landfills, reducing this important food source for some vulture species. In this context, we assessed the effect of the reduction of organic waste available and accessible for scavengers in a landfill on the visitation probability and abundance of a local Eurasian Griffon Vulture Gyps fulvus population in Central Catalonia (NE Iberian Peninsula), using a long-term dataset of captured-marked-recaptured individuals in the period 2012–2018. Our results indicated a decrease in the visitation probability due to a significant reduction of organic matter dumped into the landfill after a waste treatment centre was built (0.82 to 0.76) that may cause a permanent emigration of vultures in response to food reduction. However, the estimated annual abundance of vultures tended to grow over time due to the positive trend that regional vulture populations have experienced in recent decades. These results suggest that population processes occurring at regional scales are more relevant to vulture populations than local waste management measures. A reduction in locally available food can make a site less attractive, but species with high dispersal capacity such as vultures may overcome this issue by moving to other suitable sites. Although Griffon Vultures obtain most of the food from domestic and wild ungulates, a regional application of European directives could threaten an important alternative feeding source, especially in food shortage seasons where landfills could be supporting the energetic requirements of the species. Conservation strategies should be planned to counteract the possible negative effects of new European directives on scavenger populations.

Amazona lilacina is a threatened species endemic to Ecuador, existing across a patchwork of mangroves, lowland coastal forests, agricultural and community owned land. The species was described in 2014 and listed as ‘Endangered’ on the IUCN Red List, however, full assessment of the population was lacking. Using a combination of field observations, roost surveys and community questionnaires, conducted over the last 20 years, we provide up-to-date information on the species’ Extent of Occurrence, estimate its global population size, and evaluate its level of threat. Our results suggest the species occurs across an area of 19,890 km2 in three distinct geographically isolated subpopulations. Roost surveys across the range estimate the minimum remaining population at 741–1,090 individuals and we present evidence to suggest a 60% decline over the past 19 years in one part of the species’ range. We conducted community questionnaires with 427 people from 52 communities. The presence of pet parrots was reported in 37 communities, including 17 communities which reported pet A. lilacina. From this we predict that over half of all communities within our study area keep parrots as pets and at least 96 communities keep A. lilacina. Our findings justify an IUCN Red Listing of at least ‘Endangered’ for this species and highlight the need for conservation support. In order to assess population health in more detail, further research is required to assess genetic diversity and roost dynamics, and to identify areas that may be important for feeding and nesting throughout the range. As many of these areas are likely to overlap with community owned land, we suggest that future conservation actions should revolve around, and be led by, these communities.

Chinese Grouse Bonasa sewerzowi is threatened by human activity, especially during the breeding season, in the Lianhuashan Mountains, Gansu Province, north-western China. We conducted a series of simulations on the viability of this population using the computer program VORTEX. The simulations suggested that the population had an extinction probability of 17% in 100 years using data gathered from current field work. Sensitivity analysis revealed that the predicted population trend was most sensitive to chick mortality, offspring per female per year, and adult male mortality. The first two parameters are correlated with human activity such as nest loss due to egg collecting by local people. When we set initial population size to the same size as carrying capacity, 2,500 individuals would constitute a minimum viable population (MVP). This would require a forest area of about 3,780 ha, which is smaller than the size of the Lianhuashan reserve, but the current population does not constitute an MVP due to the small initial population size. Furthermore, we found that if chick mortality declined by 5% or the number of offspring produced per female increased by 5% (i.e. reducing nest loss) under the current situation, local reserve size and current population would constitute an MVP. Therefore, the most practical and simple conservation management tool would be to increase the breeding success of Chinese Grouse, especially by limiting human activity during the incubation period.

Assessing the impacts of invasive predators on the demography and distribution of native species is critical for understanding mechanisms of species persistence and informing the design of recovery programmes. On the oceanic island of Guam, the introduction of the predatory brown treesnake Boiga irregularis after World War II caused the near-total loss of the native forest avifauna. Localised snake control measures have been implemented since the early 1990s, yet it remains poorly understood how they have impacted Guam’s remaining native bird populations. To address this question, we combined intensive area searches of Andersen Air Force Base (AAFB) with island-wide transect surveys and opportunistic sightings to provide a comprehensive update on the distribution and abundance of Såli (Micronesian Starling, Aplonis opaca) – one of Guam’s last extant native bird species. Area searches of AAFB, where the largest remnant of the Såli population persists, revealed a 15-fold population increase since the last survey in the early 1990s, and transect surveys and opportunistic sightings indicate incipient recolonisation of other urbanised areas of northern and central Guam. We estimate the current island-wide population size at ~1,400 individuals. The population increase can likely be attributed to a combination of snake control measures and the Såli’s ability to exploit urban refugia for nesting and roosting. Although these trends demonstrate some population recovery, a skewed age ratio (>90% adults and subadults) at AAFB and a highly urbanised distribution and low abundance outside AAFB indicate that snake predation continues to strongly impact the population. More intensive snake suppression efforts, particularly in forested areas, may allow for the Såli population to attain its former distribution and abundance on Guam. More broadly, our findings reinforce the importance of urban areas as refugia for some threatened species.