We applied the ecological niche/habitat modelling approach to predict the potential winter distribution of the endangered Black-capped Vireo Vireo atricapilla. We used historical and current field records along with climatic and topographic variables to generate three different models (Biomapper, Maxent, and GARP). Using field data on species occurrence, a model was selected based on the accuracy of assessment results. A final model was obtained by eliminating those areas mapped as known unsuitable habitat, using high resolution land use/land cover data. The GARP model obtained the best accuracy values. It showed the winter distribution of the Black-capped Vireo to cover an area in western Mexico of about 141,000 km2 that runs along the Pacific coast from southern Sonora (Río Yaqui, Alvaro Obregón Dam) to the southern state of Oaxaca (Salina Cruz on the Pacific coast and Matias Romero, and inland). One third of the proposed model’s area was located at elevations of 0–500 m, while 83% occurred at elevations < 1,250 m; however, a significant area (17%) consists of sites > 1,250 m in elevation. For the most part, the distribution model proposed closely followed the tropical dry forest boundaries and clearly avoided temperate areas at higher elevations. This situation seems to be critical for the species, since the dry forest is one of most endangered Neotropical ecosystems, both nationally and internationally. Furthermore, the array of areas under protection regimes included only about 7.1% of the predicted wintering area. However, this figure could be misleading when it is considered that some protected areas are just “paper reserves” without significant conservation programmes developed in situ.

Invasive predators have decimated island biodiversity worldwide. Rats (Rattus spp.) are perhaps the greatest conservation threat to island fauna. The ground nesting Palau Micronesian Scrubfowl Megapodius laperouse senex (Megapodiidae) inhabits many of the islands of Palau’s Rock Island Southern Lagoon Conservation Area (RISL) in the western Pacific. These islands are also heavily visited by tourists and support populations of introduced rats, both of which may act as added stressors for the scrubfowl. Using passive chew-tag and call playback surveys on five tourist-visited and five tourist-free islands, we investigated if rats and tourists negatively affect scrubfowl, and if higher rat activity is associated with tourist presence. Rat detection probability and site occupancy were significantly higher on tourist visited (89% and 99%, respectively) compared to tourist-free islands (52% and 73%). Scrubfowl were detected at significantly more stations on tourist-free (93%) than tourist visited (47%) islands and their relative abundance was higher (2.66 and 1.58 birds per station, respectively), although not statistically significantly. While rat occupancy probability likewise had a non-significant negative effect on scrubfowl numbers across islands, our results show a negative relationship between tourist presence and scrubfowl in the RISL. Our findings also suggest that rat populations may be augmented by tourist visitation in the RISL. Although this situation may not seriously affect the scrubfowl, it may be highly detrimental to populations of other threatened island landbirds.

Early work on the Dark-rumped Petrel Pterodroma phaeopygia of the Galápagos Islands, Ecuador, identified colony sites and population status and alerted wildlife managers to an alarming decline in nesting numbers. Predation by introduced mammals, such as rats, cats, pigs and dogs, is the chief concern, followed by loss of nesting habitat to agricultural development. Programmes to reduce predation through poisoning and hunting, begun in 1983, increased the number of chicks fledged from the main breeding colony in eight out of nine years. Pre-breeding adults were lured by tape-recordings to ‘safe’ sites where they successfully raised chicks in artificial nests. Tape-luring offers hope for establishing new colonies on predator-free islands.

In Thailand, as for most of South-East Asia, large vertebrates are declining rapidly due to habitat degradation and increasing hunting pressure. Once relatively common in the evergreen forest of Southern Thailand, the Great Argus Argusianus argus is currently limited to a few populations, whose status is currently unknown. In this study we investigated changes in Great Argus abundance over the past 13 years in Hala-Bala Wildlife Sanctuary. Our aim was to estimate and compare the abundance and density of this species from an earlier two-year survey in 2001–2002 and ours in 2014, and to assess the effect of landscape change on its status of the species. We conducted surveys from March to August 2014 during the breeding season. We placed point counts that overlapped the line transects from the 2001–2002 survey. The results indicated a decline of > 35% in mean abundance from 2001 to 2014. In addition, male abundance has shifted and is now positively related to distance from the forest edge. High levels of human disturbance close to the forest edge may have resulted in the birds moving to the core of the forest, suggesting a need to increase protection and management of forest edge areas. In common with other studies of large vertebrates, our results confirm the importance of long-term studies to highlight the negative effects of human disturbance.

Understanding patterns of dispersal behaviour of threatened species is important in conservation biology and population ecology, especially in fragmented landscapes. Dupont’s Lark Chersophilusduponti is a threatened passerine whose European population has declined by around 40% in the last decade. To study natal and breeding dispersal of the species, we used a long-term mark-recapture dataset (2011–2019) and analysed the records of 32 males (39 dispersal movements) and five females (five dispersal movements) captured during the breeding season at Rincón de Ademuz (Valencia, eastern Spain). Adult birds had a median breeding dispersal of 154 m (Q25-Q75 = 70.0–300.3). Among these captures, two adult males dispersed to a new patch of habitat separated by more than 5,800 m. Only one out of 26 nestlings ringed was trapped as an adult bird, which occurred at a site different from the natal territory (4,500 m). Our results show a low breeding dispersal for the species and are, in essence, in agreement with previous studies carried out in the Ebro Valley metapopulation, one of the core areas for the species in Europe. Nonetheless, unlike in the Ebro Valley, we detected movements of adult birds between habitat patches. The low recovery rate of young birds suggests that they left their natal sites and moved outside the study area or that their survival rate was very low. Future studies focused on the post-fledging survival rate and natal dispersal movements are essential to determine effective conservation measures for the species. Habitat management actions in occupied and potential sites should be carried out close to the areas inhabited by the species to increase the success rate of the interventions and the effective dispersal and therefore population connectivity.

The Red River Delta in northern Vietnam is an important stopover and wintering site for migratory waterbirds. During the spring of 1994, six globally threatened and five near-threatened species were observed in the coastal areas of the Delta. According to current applications of threat categories, one of the species has Critical status (Black-faced Spoonbill Platalea minor), three are Endangered (Nordmann's Greenshank Tringa guttifer, Saunders's Gull Larus saundersi and Chinese Egret Egretta eulophotes), two are Vulnerable (Spoonbill Sandpiper Eurynorhynchus pygmaeus and Spot-billed Pelican Pelecanus philippensis) and five are Near-threatened (Asian Dowitcher Limnodromus semipalmatus, Grey-headed Lapwing Vanellus cinereus, Black-headed Ibis Threskiornis melanocephalus, Painted Stork Mycteria leucocephala and Japanese Paradise-Flycatcher Terpsiphone atrocaudata). A nature reserve, also listed as a Ramsar area, already exists in the middle of the Delta. The Cua Day Estuary in the southern part of the delta is not included in either the nature reserve or Ramsar area. However, observations of 260 Saunders's Gulls and 41 Black-faced Spoonbills, which represent 9% and 12% of the estimated respective world populations, indicates the international importance of this area. The major threats to the waterbirds using the delta are reclamation of intertidal sand- and mudflats for aquaculture, increased disturbance associated with collection of sea products and hunting. Recommendations are made for future conservation actions.

The Corncrake Crex crex is a rail which inhabits tall grass and herbage and migrates between breeding grounds in northern Eurasia and wintering areas in south-east Africa. Corncrake populations are known to have been declining for more than 100 years in some countries and declines have now been reported for almost all of the European part of the species's world range. It appears that mechanized mowing early in the breeding season reduces the production of young to a point below that needed to maintain the population. It might therefore be expected that Corncrakes would be least abundant in countries where the management of agricultural grassland is most mechanized and intensive. To test this hypothesis, an analysis of available statistics for agricultural intensity and Corncrake population density in different European countries was undertaken. Milk yield per dairy cow and measures of the use of fertilizers and tractors were used as indices of the intensity of management of agricultural grassland. Corncrakes were least abundant in European countries with high levels of milk yield, fertilizer and tractor use. Countries with low indices of agricultural intensity and high Corncrake abundance are in eastern Europe where continuing political change makes the future course of agricultural development difficult to foresee. The persistence of the Corncrake in this region depends on the adoption of agricultural policies which do not encourage further intensification of grassland management in those areas which support important populations.

Movement ecology and environmental factors are topics of paramount importance to consider when planning conservation programmes for target species. Here we discuss this topic by reviewing the available information related to the Egyptian Vulture Neophron percnopterus, with reference to the remnant breeding population of Southern Italy, of high conservation concern and subject of a long-term captive-breeding re-stocking programme. We describe how adverse wind conditions over the Central Mediterranean Sea make the sea-crossing challenging with detrimental effects on the survival of inexperienced birds, and coupled this information with count data of migrating Egyptian Vultures. Furthermore, we indicate how low population size and scarce opportunities in meeting migrating conspecifics could potentially lead juvenile Egyptian Vultures to follow unfavourable migratory routes, with possible repercussions on survival. We postulate how these concomitant factors could be indirectly influencing the long-term survival of this small population, principally affected by anthropogenic threats. We also discuss how the same factors could actually be affecting captive-bred young individuals released in late summer in southern continental Italy, in the framework of the restocking programme. An integrative approach with tailor-made release methods, which also takes into account the age of released birds and geographical and environmental factors, would likely be useful for a more goal-oriented and long-lasting conservation outcome, for the preservation of this endangered scavenger.

The Galapagos Petrel Pterodroma phaeopygia is endemic to the Galapagos Archipelago, where it nests on only five islands. The species is considered ‘Critically Endangered’, mostly due to the effects of alien invasive species, which impair its reproductive success. During 2002–2003 we studied the breeding biology of the petrels nesting on San Cristóbal island. The study revealed particular characteristics of the San Cristóbal petrel population and differences compared to those of other islands, mostly related to nesting habitat, phenology, reproductive success and causes of mortality. On San Cristóbal, petrel nests were primarily located along ravines, in areas of dense vegetation cover formed by the endemic shrub Miconia robinsoniana and a wide variety of native ferns. Over 90% of the nests on the island were located on private agricultural land. The petrel population has a prolonged reproductive period covering 10 months. Laying dates occurred mostly from May to October, with a peak during August, although eggs may be occasionally laid between November and March. The incubation period averaged 50.8 days (range: 46–53), and parental care 103.7 days (range: 98–108). Overall reproductive success was 23.6%; 63.8% for eggs and 37.1% for chicks. Predation by rats was the primary cause (72.2%) of nest failure. Rat control campaigns and clearing of exotic plant species in areas of high density of petrel nests, as well as promoting cooperation agreements between conservation authorities and landowners of the properties where nests are located, are suggested among other critical management measures intended to reduce nest mortality and ensure the survival of the San Cristóbal petrel population.

The status of breeding pelicans and cormorants is assessed in the area from the Danube delta (Romania) to the northern part of the Crimean peninsula. Four breeding species occur in inland and coastal wetlands: Dalmatian Pelican Pelecanus crispus, Great White Pelican Pelecanus onocrotalus, Great Cormorant Phalacrocorax carbo and Pygmy Cormorant Phalacrocorax pygmeus. Data on clutch size and breeding success are given. Historically, all four species were restricted to the Danube delta. Currently, with the exception of Dalmatian Pelican, they all breed successfully on the eastern Black Sea coast in the Ukraine. There are many conservation problems that will jeopardize the breeding of these species in the future if nothing is done.

From 1950 to 1999 there was a substantial decrease in the number of Imperial Eagles Aquila heliaca breeding in the Baikal region of eastern Russia, but there have been no apparent changes in habitat or breeding success within this region. Identification of wintering and stopover sites is therefore necessary to discover whether negative impacts at these sites could be causing the observed population decline. To this end, we satellite-tracked four juvenile Imperial Eagles from Lake Baikal to their wintering grounds. Two sibling eagles were tracked in 1998 and two siblings from a different brood in 1999. The eagles migrated through eastern Mongolia and central Inner Mongolia (China), and wintered from south China to Thailand. Siblings independently used the same migration flyway, and the flyway was different between families. These results provide useful information for determining the causes of the decline in the population of Imperial Eagles in the Baikal region.

The Black Woodpecker Dryocopus martius is the largest woodpecker of the Palearctic Region and it has been recognised as a keystone species whose presence provides critical resources to secondary cavity-users in European forest ecosystems. Here we investigate cavity tree and foraging-habitat selection of Black Woodpecker in three natural parks located in the central and eastern Italian Alps and included in the Natura 2000 network. A total of 94 cavity trees were identified, showing a minimum diameter of 35 cm and a mean diameter of 51 cm. We counted 30 active nests, but only 40% were newly excavated. Silver fir Abies alba and larch Larix decidua were preferred as cavity trees, with silver fir also associated with habitat surrounding the cavity trees. Norway spruce Picea abies and Silver fir were found to be positively associated with the surroundings of feeding sites. Logistic regression models identified the average diameter at breast height and the average tree crown height as significant predictors, positively associated with both cavity trees (AUC: 0.988) and cavity tree plots (AUC: 0.866). Also, the total volume of dead logs and the percentage of understorey cover turned out to be significant predictors of feeding sites, showing a positive and a negative association, respectively (AUC: 0.708). Cross validation of logistic regression models indicated that only cavity tree models can be considered useful tools in conservation practice. Overall, our results indicated that the Black Woodpecker behaves like an opportunist when choosing feeding sites. On the other hand, our results also indicate that the Black Woodpecker clearly behaves as a demanding species when it selects cavity trees, showing a hierarchical pattern in habitat selection and a marked preference for large trees with high crown height. We discuss the implications of our results for the conservation of the Black Woodpecker in Natura 2000 alpine sites.

West African flood-plains have undergone major land-use transformations in the second half of the 20th century. To obtain insight in the effect of flood-plain development for irrigated rice cultivation on the abundance, richness, and diversity of Palearctic and Afrotropical raptors, we conducted monthly transect surveys covering dry and wet seasons in four major habitats on the Waza-Logone flood-plain of Cameroon: dry grasslands, cultivated grasslands, rice fields, and seasonally flooded grasslands resembling natural flood-plain vegetation. We recorded 36 raptor species among 2,533 individuals, dominated by Black Kite Milvus migrans, which comprised 42% of counts. Although richness and diversity were not related to land-use for Palearctic raptors, Afrotropical raptor diversity was higher on the flooded grasslands compared to the newly created cultivated habitats and dry grasslands. The abundance of Afrotropical raptors did not significantly differ across habitats but was lower in rice-fields when Black Kite and Hooded Vulture Necrosyrtes monachus were excluded. Conversely, Palearctic raptor abundance was highest in post-harvest rice fields, demonstrating the importance of the rice fields as foraging habitat for Palearctic raptors. Further transformation of West Africa’s flood-plains is expected, reducing their capacity for Afrotropical raptors, while Palearctic raptors may benefit from expansion of rice-fields, but more research is needed on their vulnerability to pesticide use.

Green areas are key habitats for urban avifauna. Urban parks stand out from other anthropic habitats especially in providing trophic resources for many bird species. Consequently, modifications of these green zones can imply major changes in urban biodiversity. Potential pernicious urban remodelling is taking place in parks of eastern Spain because natural grass is being replaced with artificial grass to save water and to avoid management. This study aimed to determine whether remodelled parks with artificial grass harbour lower avian diversity (alpha, beta and gamma diversity) than traditional parks with natural grass. We surveyed 21 parks with artificial grass and 24 parks with natural grass in 18 towns of the Valencia Region in autumn 2020. In each park, we carried out 5-minute and 25-m radius point counts for determining bird species and their abundance. The effects of park area and grass type on alpha diversity (species richness, Shannon diversity index, Pielou’s Evenness and total abundance) were tested by means of GLMs. Differences in beta diversity and its components (nestedness and turnover) were also analyzed with the Bray-Curtis dissimilarity index. Gamma diversity was assessed by means of species accumulation curves. Finally, differences in community composition were tested by PERMANOVA and SIMPER tests. The parks with natural grass always harboured higher gamma diversity, species richness and abundance. Turnover was higher in parks with natural grass, whereas nestedness was higher in artificial grass parks. Differences in community composition were due mainly to abundance differences in common ground-feeding birds. We highlight that the trend of replacing natural by artificial grass in urban parks has harmful effects on urban bird communities and is a threat to bird conservation. Although artificial grass might save water, the effects on urban biodiversity should be carefully evaluated.

The historical distribution of the Red-crowned Crane Grus japonensis together changes in its breeding and wintering grounds in China are reviewed. According to historical information the bird mainly bred in Heilongjiang and Jilin Provinces and wintered at coastal regions near the Yangtze estuary. Due to geographical and anthropological changes, the breeding grounds gradually moved to the west and south while the wintering grounds moved northward. Efforts have been made to protect this endangered species but factors still exist which restrict further development of the population.

This study investigated the distribution and habitat selection of the globally threatened East Coast Akalat Sheppardia gunningi sokokensis in Arabuko-Sokoke Forest, the Shimba Hills (both Kenya) and the lowland East Usambara Mountains (Tanzania). The species is more abundant than originally thought. In Arabuko-Sokoke Forest, akalats occur in two of the main vegetation types, and an estimated 7,500–9,000 territories represent one of the largest populations of this species in the world. Akalats occurred at similar densities to those in Arabuko-Sokoke (c. 0.5 pairs/ha) in parts of Shimba Hills and East Usambaras, but were more patchily distributed. This akalat prefers areas where the undergrowth is partially open with large amounts of dead wood. It forages on or near the ground. In Arabuko-Sokoke Forest, areas where akalats were present had a higher abundance of ground-dwelling arthropods than areas where they were not. The akalat inhabits both primary forest and regenerated areas that have been selectively logged probably more than 20 years ago. Despite its relatively high densities where it occurs, this species (like other threatened birds in the East African coastal forests) is very patchily distributed and dependent on a habitat that is now highly fragmented and under considerable human pressure. The conservation situation in Arabuko-Sokoke gives cause for concern, and the destructive effects of a large elephant population threaten the forests of the Shimba Hills. The conservation status of the lowland Usambara Mountains is probably better and more stable.

Pale-headed Brush-finch Atlapetes pallidiceps is on the verge of extinction, with fewer than 100 individuals surviving in an area of less than 4 km2 in the Yunguilla valley in the province of Azuay, southern Ecuador. A reserve created for the protection of the species held 10 or 12 pairs in 1999, 14 in 2000, 16 in 2001 and 17 in 2002. Nearly all males had distinctive songs, showing little or no change from one year to the next. The yearly turnover of singing males was 40% in both 2000 and 2001 (4/10), and 29% in 2002 (4/14). Altitudinal range of A. pallidiceps was 1,650–1,950 m. Habitat was typical of regenerating landslides and fallow fields, composed of early succession growth in the ecotone between dry, thorny valley-bottom and humid forest remnants on the upper slopes. Territory size averaged 1.0 ha (range 0.7–1.4 ha, n = 37), and nearly all territories were within 100 m of a stream or an irrigation channel. Most were on steep slopes with Chusquea bamboo, and deciduous bushy cover with few or no spines, typically including the composite Steiractinia sodiroi, and with some open areas. Although habitat improved considerably between 1999 and 2002, some territories were vacant some years. Shiny Cowbird Molothrus bonariensis parasitism was noted, and could be even more important than habitat as a limiting factor of the population size. The song of A. pallidiceps was found to be similar to songs of several other Atlapetes spp. in general pattern. Diet was composed of arthropods, fruit and a few seeds. Arthropods were almost invariably picked from the bark on upper- and under-surfaces of twigs and small branches. Seeds were taken from the ground. Young (cowbirds) were apparently only fed insects. Between 1,800 and 1,950 m A. pallidiceps occurred with Rufous-naped Brush-finch A. latinuchus, which replaces it at higher elevations. Territories did not overlap, and where they met, A. latinuchus was confined to slightly taller and more humid vegetation, or to forest. In interspecific encounters A. pallidiceps was subordinate to Stripe-headed Brush-finch Buarremon torquatus, with which it coexisted in all its territories. Habitat management began in 2002, and limited cowbird control is planned to begin in 2003.

A rapidly developing tourism industry, concentrated in coastal regions, is suspected to seriously impact upon biodiversity in the global conservation priority of the insular Caribbean. In St Lucia, construction of tourism infrastructure in the coastal dry forest threatens the Endangered White-breasted Thrasher Ramphocinclus brachyurus. Long-term protection of habitat is vital, but design of such conservation action is constrained by lack of data on the species' distribution and population responses to habitat change and fragmentation. Distance sampling surveys were conducted in 2006 and 2007 to estimate numbers and map the distribution of the two remaining sub-populations. White-breasted Thrashers in St Lucia were estimated to number around 1,200 individuals, with roughly 1,050 birds occupying just over 600 ha of dry forest in the Mandelé area. We demonstrate that tourist development companies will likely soon own land constituting around 40% of the species' extent of occurrence on St Lucia, and nearly 35% globally, and that ongoing and planned tourist developments threaten around one third of the St Lucian White-breasted Thrasher population. Given the size of these potential impacts, it is vital that patches of dry forest to the west and north of a development site in the Mandelé area are safeguarded. These sites support White-breasted Thrashers at high density and are contiguous with an existing forest reserve. Other important conservation measures include preserving stands of connected mature dry and riparian forest inside the tourist development sites, alongside invasive predator control.

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.

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.