Mediterranean mountains are biodiversity hotspots where northern species occur surrounded by drier and warmer lowlands. In this context, global warming is pushing these species to higher elevations. This paper assesses whether forest birds have experienced a shift upwards over the elevation gradient in the last 35 years in the Guadarrama Mountains (600–2,400 m asl; central Spain). Alternatively, the paper tests whether the reported shifts are related to changes in forest structure resulting from rural abandonment and/or forest management. To do this, sampling carried out from 1976 to 1980 along the elevation gradient was repeated in 2014–2015. In addition, the habitat preferences of birds were used to test if the elevation shifts were related to changes in forest structure. Results show that the mean range position of birds associated with tree cover shifted downwards, a trend supported by an increase in tree-dependent birds at mid-elevations. These trends suggest that an increase in tree cover has buffered the altitudinal shifts of forest birds predicted by climate warming. Results also suggest that proper forest management may improve the resilience of forest bird communities to the pervasive effects of climate warming.

With a decline exceeding 30% over three generations, the once-common European Turtle-dove is now considered globally threatened by IUCN. As a legal game species in 10 European countries, the recent International Single Species Action Plan for this species highlighted the need to carry out an assessment of the sustainability of current levels of hunting. In 2013–2014, the Western European population was estimated at 1.3–2.1 million pairs, and the hunting bag in the same region to be 1.1 million birds. Using the Demographic Invariant Method, we assessed whether current levels of hunting harvest within Europe constitute overexploitation of the western flyway European Turtle-dove population. We calculated the maximum growth rate λmax that a population might achieve in the absence of any additive mortality. Then we estimated the potential maximum harvestable population fraction (P) allowed by excess population growth. We explored a wide range of plausible scenarios relating to assumed demographic rates, geographic scope of the flyway and management objectives. λmax was estimated to lie between 1.551 and 1.869. Current levels of hunting along the western flyway are more than double the sustainable fraction (P) under all suitably conservative scenarios, and only fall below this threshold under the most restrictive assumptions. We conclude that current levels of legal hunting along the western flyway are unlikely to be sustainable. Reducing uncertainty associated with assessments of the sustainability of turtle dove hunting will require improved information on (in order of decreasing importance) current levels of hunting, adult survival, age structure and population size.

The White-winged Snowfinch Montifringilla nivalis nivalis is assumed to be highly threatened by climate change, but this high elevation species has been little studied and the current breeding distribution is accurately known only for a minor portion of its range. Here, we provide a detailed and spatially explicit identification of the potentially suitable breeding areas for the Snowfinch. We modelled suitable areas in Europe and compared them with the currently known distribution. We built a distribution model using 14,574 records obtained during the breeding period that integrated climatic, topographic and land-cover variables, working at a 2-km spatial resolution with MaxEnt. The model performed well and was very robust; average annual temperature was the most important occurrence predictor (optimum between c.-3°C and 0°; unsuitable conditions below -10° and above 5°). The current European breeding range estimated by BirdLife International was almost three times greater than that classified as potentially suitable by our model. Discrepancies between our model and the distribution estimated by BirdLife International were particularly evident in eastern Europe, where the species is poorly monitored. Southern populations are likely more isolated and at major risk because of global warming. These differences have important implications for the supposed national responsibility for conservation of the species and highlight the need for new investigations on the species in the eastern part of its European range.

Reintroduction to, or reinforcement of, threatened wild populations are commonly used conservation strategies. Reintroductions of the Southern Ground-hornbill Bucorvus leadbeateri have been tested as a potential conservation tool for this vulnerable species since 1995. Forty-two individuals have been reintroduced under varying management strategies. We analysed the outcomes of these attempts to assess which factors contributed most to success or failure. The species exhibits complex social learning and hierarchy, and is long-lived, with delayed sexual maturity. Immediate survival was significantly affected by the season in which the release was done and by the quality of the released birds. The best-quality release birds were reared with wild behavioural characteristics and were well-socialised to captive conspecifics prior to being placed into managed groups (‘bush schools’), where social learning was led by an experienced, wild alpha male. Once reintroduced birds had survived their first year after release, continued wild experience and wild mentorship significantly affected their survival. Since sample sizes limited the rigour of some statistical analyses, other factors were considered that may also determine success. These quasi-experimental reintroductions revealed novel threats to the species, such as the importance of a nest to group cohesion, that harvested second-hatched chicks provide viable release birds, which essentially doubles wild productivity, and that reintroductions generate valuable civil society awareness of the plight of the species.

The Vietnam Pheasant Lophura edwardsi (including L. hatinhensis) is only known from a small area of central Vietnam, where it occurred in wet forest below 300 m. It is probably extinct in the wild, but some 1,500 birds, derived from 28 individuals caught in 1924–1930, survive in captivity. Guidelines for reintroducing galliforms date from 2009. Subsequent literature was reviewed for new research findings to help maximise the chances of success in reintroducing birds. Studies confirmed that non-parent-reared captive-bred galliforms survive poorly, primarily owing to inadequate anti-predator responses. These reflect both genetic and ontogenetic unsuitability to wild conditions, with progressive maladaptation of stock being related to the number of generations spent in captivity (at least 35 in the case of Vietnam Pheasant). To compensate as far as possible for this deficiency, a reintroduction programme should use: environmental enrichment (including the provision of perches in aviaries), dietary enrichment (especially involving practice with live food), parent-rearing over several generations (although how many are needed for a species almost a century in captivity is unknown), soft releases (allowing full familiarisation with the future environment over at least 50 days), rigorous anti-predator training (against both air and ground attacks), anti-predation release stratagems (relocating and deterring predators, releasing birds at several stations, offering post-release support), determining appropriate numbers (per batch, with at least 300 in total per site) and time-frame for release (around five years) and the selection of fully suitable releasees in (as far as possible) naturally formed social groups, including parent-guided offspring aged around four months. Six sites need survey for extant populations or use for reintroduction, and the choice of reintroduction site will depend primarily on habitat extent and condition. The costs of these measures will be high and the overall project schedule will need to extend beyond the overall five years currently planned.

The Área de Conservación Osa (ACOSA) contains the largest population of Scarlet Macaws Ara macao in Costa Rica. Despite their influence on ecosystem dynamics and status as a flagship species, empirical data on the foraging patterns of this population is lacking. This information is crucial in implementing effective conservation strategies, particularly reintroduction attempts. Observations of feeding behaviour were made systematically over a 12-month period to provide the first direct examination of Scarlet Macaw diet within the ACOSA region. Scarlet Macaws feed on various items including seeds, flowers, bark, and leaf-gall larvae. Key findings included a demonstration of a smaller dietary niche breadth than that recorded for other Central American populations, use of button mangrove Conocarpus erectus, a species not previously recognised as a food source for Scarlet Macaws, and a heavy reliance on an exotic non-native species, Terminalia catappa. We argue that whilst human-modified coastal locations may present viable habitat for Scarlet Macaws, anthropogenic influences including the removal of native food sources and proliferation of exotic and cultivated species have left the Scarlet Macaws of the ACOSA particularly dependent on a small number of species.

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.

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.

The Parc National du Banc d’Arguin in Mauritania hosts the largest concentrations of coastal waterbirds along the East Atlantic Flyway. In spite of this importance, a review of the changes in the numbers of waterbirds in the area is lacking since the first complete count in 1980. Here we analysed the seven complete waterbird counts made since then, and the additional yearly counts made in one subunit (Iwik region) since 2003. We present evidence for changes in the community composition of waterbirds over the past four decades. Total waterbird numbers showed a decrease between 1980 and 2017, with only Great White Pelican Pelecanus onocrotalus showing a significant increase in numbers. Five species showed significant declines: Long-tailed Cormorant Phalacrocorax africanus, Red Knot Calidris canutus, Bar-tailed Godwit Limosa lapponica, Eurasian Curlew Numenius arquata, and Western Marsh Harrier Circus aeruginosus. In the remaining species, the variation in numbers between counts was too large, and the number of complete counts too small, for trends to be detected. The yearly counts at Iwik region also showed sharp decreases in the numbers of Red Knot, Bar-tailed Godwit, and Marsh Harrier, but not of Long-tailed Cormorant and Eurasian Curlew. A multivariate analysis revealed a significant change in species composition over time, which was caused mainly by changes in the species depending on the intertidal mudflats for feeding (generally in decline) vs. the species depending on fish and crustaceans in the sublittoral and offshore zones (often showing increases).

Ruddy-headed Goose Chloephaga rubidiceps is the smallest of the five South American sheldgeese and has two separate populations: one sedentary, which resides in the Malvinas/Falkland Islands and one migratory that overwinters mainly in the Pampas region, Argentina and breeds in Southern Patagonia. The Ruddy-headed Goose’s continental population has decreased considerably, and recent estimates indicated that the population size is less than 800 individuals. In Argentina and Chile, this population is categorised as endangered. Understanding migration across vast landscapes is essential for the identification of factors affecting the survival of this endangered population and for the application of effective conservation measures. We aim to provide the first documentation of the complete migration cycle of Ruddy-headed Goose, and to analyse their annual migration in detail, including identification of stop-over, breeding and wintering sites, and to compare migration timing during spring and autumn migration. Adults were captured in the southern Pampas and equipped with solar satellite transmitters in 2015 and 2016. We analysed the influence of season (spring vs autumn migration) on the number and duration of stop-overs, distance travelled and overall migration speed using Generalized Linear Mixed Models. Our results showed that tracked geese used the eastern Patagonian route to reach their breeding grounds and take the same route after breeding. Spring migration was significantly faster than autumn migration, at least based on the number of days spent in their stop-overs. Stop-overs were closer to the final destination, either during spring and autumn migrations, though some of them were not used during subsequent migrations. Our migration cartography for Ruddy-headed Geese, together with the timing and location data, should be used to improve conservation efforts directed at this species and might contribute to the modification of the current status of ‘Least Concern’ under the IUCN criteria.

The extent of intertidal flats in the Yellow Sea region has declined significantly in the past few decades, resulting in severe population declines in several waterbird species. The Yellow Sea region holds the primary stopover sites for many shorebirds during their migration to and from northern breeding grounds. However, the functional roles of these sites in shorebirds’ stopover ecology remain poorly understood. Through field surveys between July and November 2015, we investigated the stopover and moult schedules of migratory shorebirds along the southern Jiangsu coast, eastern China during their southbound migration, with a focus on the ‘Critically Endangered’ Spoon-billed Sandpiper Calidris pygmaea and ‘Endangered’ Nordmann’s Greenshank Tringa guttifer. Long-term count data indicate that both species regularly occur in globally important number in southern Jiangsu coast, constituting 16.67–49.34% and 64.0–80.67% of their global population estimates respectively, and it is highly likely that most adults undergo their primary moult during this southbound migration stopover. Our results show that Spoon-billed Sandpiper and Nordmann’s Greenshank staged for an extended period of time (66 and 84 days, respectively) to complete their primary moult. On average, Spoon-billed Sandpipers and Nordmann’s Greenshanks started moulting primary feathers on 8 August ± 4.52 and 27 July ± 1.56 days respectively, and their moult durations were 72.58 ± 9.08 and 65.09 ± 2.40 days. In addition, some individuals of several other shorebird species including the ‘Endangered’ Great Knot Calidris tenuirostris, ‘Near Threatened’ Bar-tailed Godwit Limosa lapponica, ‘Near Threatened’ Eurasian Curlew Numenius arquata and Greater Sand Plover Charadrius leschenaultii also underwent primary moult. Our work highlights the importance of the southern Jiangsu region as the primary moulting ground for these species, reinforcing that conservation of shorebird habitat including both intertidal flats and supratidal roosting sites in this region is critical to safeguard the future of some highly threatened shorebird species.

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.