The Spoon-billed Sandpiper Eurynorhynchus pygmeus (IUCN Category: Critically Endangered) is in rapid decline. Data from across the entire breeding range (Chukotka and Koryakya in the Russian far north-east) and especially from the well-studied southern core breeding area at Meinypilgyno, confirm the continuing strong decline. At four breeding sites, where more than two counts were available for analysis, the decline was estimated at 26% per annum between 2002 and 2009, or an 88% decline over this period. Allowing for unsurveyed areas, this equates to a decline from a total population of approximately 1,000 breeding pairs in 2000 to 120–220 in 2009. Breeding studies at Meinypilgyno in 2003–2007 (not 2006) showed that the proportion of nests hatching at least one chick was 0.65 and once chicks left the nest, the mean brood size of chicks up to one week old was 1.99. Where it was possible to follow broods, 0.61 chicks fledged per nesting attempt. Survival and recruitment analysis of birds ringed at Meinypilgyno indicated that annual adult survival did not significantly differ over the 2003–2009 study but that recruitment in to the adult breeding population was effectively zero in all but one year of the study (2005). Resighting data for the last two years of the study were sparse due to very low numbers of marked adults being recorded and survival rates over the last 2–3 years of the study must therefore be treated with caution. The analysis therefore indicated that after fledging, survival during immaturity must be very low, leading to a low (or no) recruitment into an ageing population. Recent observations collated from the non-breeding areas confirm the declining trend observed in the breeding areas and imply that the main threats to the population lie along the migration route or in the wintering areas. These are poorly known although hunting in the wintering areas has been identified as a major mortality factor. Other threats include major loss of their intertidal habitats, and collection of birds on the breeding areas by specimen collectors. Improved monitoring in both the breeding and non-breeding areas as well as research on juvenile survival is recommended. Concerted international conservation action is essential if this species is to avoid extinction. This requires (i) improved understanding of the main wintering and staging areas and associated threats; (ii) addressing those threats that can be tackled with immediate effect, such as hunting; (iii) continued long-term monitoring on the breeding areas; (iv) an exploration of other potential breeding areas; (v) conservation action at all important stop-over and wintering sites along the entire flyway and (vi) consideration of a captive-breeding programme to ensure the survival of this species.

Anthropogenic emissions of mercury have doubled over the past two centuries. Mercury is a dangerous neurotoxin that threatens human health and fish and wildlife populations. The effects of mercury on birds have been relatively well-studied in the laboratory and in nature. Several aspects of neurology, physiology, behaviour, and reproduction have been shown to be adversely affected. Many studies have documented ataxia, lethargy, reduced appetite, reduced egg production, poor hatching success, and aberrant parental care in birds exposed to mercury.

The majority of the research done to date, however, has been focused on select taxa (waterbirds), trophic levels (piscivores), habitat types (aquatic systems), geographic regions (North America and Europe), and life history stages (reproduction), leaving the assessment of mercury's threats to birds incomplete. Successful bird conservation strategies are dependent on a comprehensive understanding of the threats facing populations. Here, I discuss the significant knowledge gaps that remain and subsequently suggest priorities for future mercury research in birds. Studies of mercury in terrestrial, insectivorous, and/or passerine species, and how mercury affects migration are especially recommended to fill gaps in our present understanding.

Continental-scale bird population estimates are used as a decision-support tool in conservation plans. The calculation of these estimates includes the use of density values and survey data from one or multiple sources extrapolated to the geographic scale of interest. In this paper, we use migration count data from a migration monitoring project in Veracruz, Mexico, to revise existing North American population estimates of seven species of waterbirds, New World vultures, and diurnal raptors. In two species of waterbirds, we suggest that existing estimates are low and propose a mechanism to correct these figures. In the remaining five cases, we also determine present estimates are low, but use our data to provide new continental-scale values. We discuss the importance of refining population estimates using data from a diverse suite of field methods as a means to overcome the limitations of the single-survey-based estimates.

Stable isotopes (δD, δ13C, δ15N) were measured in adult and juvenile Amur Falcon Falco amurensis feathers to understand the migratory connectivity of this species. Using the OIPC (Online Isotopes in Precipitation Calculator) and a calibration curve for American Kestrels Falco sparverius we predicted the breeding range of South African Amur Falcons in the Palaearctic. δD values for juvenile feathers (mean ± SE = -58.1 ± 2.5‰, range -83.9 to -25.7‰) and predicted Palaearctic annual precipitation values indicated that juvenile Amur Falcons in South Africa originated from across their entire Palaearctic range. This rejects the leapfrog migration hypothesis and suggests the widespread movement of birds south, with a funnelling effect into the subregion where they become concentrated over a narrower distribution range. Adult δDf values were more depleted (-37.4 ± 1.8‰, range = -71.3 to -9.3‰) than predicted annual precipitation values for sites where feathers moulted in South Africa (-20.2 ± 0.9‰) but there was no correlation between δDp and δDf. This, together with significant variation of δ13C among sites and annual fluctuations in roost sizes, suggests that roost site fidelity is low in the overwintering range. Populations not confined to breeding sites in South Africa are able to move widely across the subregion, feeding on a broad range of arthropods that become seasonally abundant during the austral summer. Total population estimates for South Africa are significantly lower than global estimates so a significant proportion of the population may not overwinter in South Africa or global populations are significantly lower than estimated. In South Africa, roosts that number hundreds to thousands of individuals are often in large exotic trees, e.g. Eucalyptus sp. They are often tolerant of disturbance at roosts which may be of little concern for their conservation. Habitat changes in the overwintering range in South Africa though, particularly due to agriculture, afforestation and strip mining, may affect global population numbers. There is also concern over the persecution of birds along their migratory route.

The ‘Critically Endangered’ Cone-billed Tanager Conothraupis mesoleuca was described in 1939, based on a single specimen collected in the state of Mato Grosso, western Brazil. Not seen again in the wild until 2003, this poorly-known species was rediscovered in Emas National Park, in the Brazilian state of Goiás. We describe here the discovery of a new population of Cone-billed Tanager in Chapada dos Parecis, along the upper Juruena River basin, in the state of Mato Grosso. The birds were always detected in (or near) flooded habitats along rivers. At least 40 individuals were found, but the population may be larger, since areas of potential habitat are available in the upper Juruena basin and these have not yet been surveyed. We also provide here the first information on the biology and behaviour of the species based on observations in Juruena and Emas, as well as a first description of the female. Historical documents and our records support our suggestion that “Juruena”, i.e. the type locality of the Cone-billed Tanager, refers to the Juruena telegraph station (12°50’S, 58°55’W). Considering that the range of the species is being settled, research on different aspects of its biology are urgent.

We estimated the breeding population size and assess the habitat relationships of Black-bellied Sandgrouse in the Eastern Canary Islands (Fuerteventura, Lanzarote and La Graciosa, Spain) by means of a survey based on 1,787 0.5-km line transects and distance sampling done in 2005 and 2006. The population comprised 2,906 individuals (90% CI: 2,363–3,562), which is much higher than the numbers estimated in previous reports based on partial surveys, and constitutes 20% of the total Spanish population. Sandgrouse in the Canaries are currently restricted to Fuerteventura, where 70% of the population gathers in four areas that encompass just 16.7 % of the island and are largely within Special Protection Areas classified under the EU Birds Directive (except the area of Tefia-Ampuyenta, first in absolute number of individuals). The environmental characteristics that maximize the probability of occurrence of the sandgrouse in Fuerteventura (probability = 0.196) are: treeless non-cultivated areas of sandy soils without bare bedrock, with a rock cover less than 44%, located in non-coastal areas with an average terrain slope less than 27.5%, at more than 400 m from the nearest urban area, with less than 795 m of dirt roads per 20 ha, with at least 0.9% of shrub cover and a NDVI index higher than 53. Sandgrouse were closer to human settlements in midsummer than in March, perhaps being attracted to artificial pools surrounding villages. Similar habitat characteristics exist in nearby Lanzarote, where the species could hypothetically reach densities as high as 4–5 birds km−2. Possible reasons for the absence of sandgrouse in this island are discussed.

The taxonomic criteria used as bases for endangered species lists can affect conservation policy decisions. We emphasize that the use of different taxonomic units affects the baselines of such lists. Recent taxonomic reviews for the Mexican avifauna provided the tools for assessing this effect on a highly diverse avifauna which is currently in need of serious conservation actions. Most ornithologists have used a taxonomy based on the biological species concept (BSC) to make decisions on species limits and therefore to set them into endangered species lists. However, the application of the phylogenetic species concept (PSC) as an alternative for delimiting species, results in a different panorama of what should be protected. Our analysis shows that the current official Mexican endangered species list, BSC based, encompasses 371 birds, ranked as 277 species and 94 subspecies. The same list of protected forms changes under the phylogenetic species concept because 47 of them are not recognized as valid species, while another 28 forms merit higher levels of protection. Additionally, under this concept another 11 forms should be candidates for inclusion based on their restricted distribution. We call attention to the fact that the use of one or another species concept affects endangered species lists.

Population size estimates of waders, gulls and terns passing through or breeding in Central Asia are very scarce, although highly important for global flyway population estimates as well as for targeting local conservation efforts. The Tengiz-Korgalzhyn region is one of the largest wetland complexes in Central Asia. We conducted surveys in this region between 1999 and 2008 and present estimates of population size as well as information on phenology and age structure for 50 species of Charadriiformes. The Tengiz-Korgalzhyn wetlands are especially important for Red-necked Phalaropes Phalaropus lobatus and Ruffs Philomachus pugnax with, respectively, 41% and 13% of their flyway populations using the area during spring migration. The region is also an important post-breeding moulting site for Pied Avocets Recurvirostra avosetta and Black-tailed Godwits Limosa limosa used by, respectively, 5% and 4% of their flyway populations. Besides its key importance as a migratory stopover site, the study area is a key breeding site for the Critically Endangered Sociable Lapwing Vanellus gregarius, the Near Threatened Black-winged Pratincole Glareola nordmanni and for Pallas’s Gull Larus ichthyaetus with 16%, 6% and 5% of their world populations, respectively. We identified 29 individual sites that held more than 1% of the relevant flyway populations of at least one species of Charadriiformes. Including data on other species of waterbirds (mainly waterfowl), there were 93 sites that qualify for Important Bird Areas (IBA). About half of them are protected in a state nature reserve, while an additional 20% are recognised as IBAs. Nevertheless, 28 important sites are currently not recognised as IBAs nor are they protected by other conservation means. These sites require conservation attention.

Over the past half century, grassland birds in Europe have declined dramatically and in order to maintain and restore their populations it is critical to understand how habitat structures and quality within pastures affect birds. This study investigated the effects of habitat structure and pasture abandonment on grassland birds in IBA Ponor, western Bulgaria. Birds were sampled using the point count method at 143 randomly located circular plots and a total of 1,401 observations of birds from 31 species were recorded. The results showed that habitat complexity, management and landscape position influenced bird community structure and species occurrence within the upland pastures. Extensively grazed pastures supported higher structural complexity of vegetation cover and higher bird-species richness and diversity compared with abandoned ones. Moreover, bird species with a preference for grazed rather than abandoned pastures had higher conservation status and most were associated with shrub cover. To maintain high levels of avian diversity, habitat complexity within pastures should be maintained through extensive grazing, to ensure availability of scrub vegetation wherever possible. Finally, this study provided evidence that agri-environmental schemes should not be directly extrapolated from one country or region to another without been tested first, because within the same management, differences in habitat structural characteristics may exist due to the landscape and socio-economic characteristics of the region.