Migratory birds are critically dependent on adequate wintering habitats for their long-term survival. Cantabrian farmland, a mixed agricultural landscape extending across the coastal lowlands of northern Spain, constitutes an important wintering area for many short-distance migrants coming from central-western and northern Europe. Unfortunately, the Common Agricultural Policy of the European Union and national afforestation schemes have resulted in a massive replacement of farmland by pine Pinus spp. and eucalypt Eucalyptus sp. plantations. This work assesses the importance of Cantabrian farmland as wintering grounds for short-distance European migrants and for wintering species that originate in nearby woodlands. We examined the seasonal changes in passerine bird populations in the Cantabrian region and used winter ringing recoveries obtained in the area to evaluate the contribution made by European migrants to winter populations. Bird communities were surveyed along 299 500-m long transects distributed between 67 farmland patches, 67 lowland forests and 14 upland forests. Winter assemblages were more diverse and species more abundant in farmland than in lowland or upland forests, whereas these differences were smaller in the spring. Bird numbers in farmland tripled in winter, numbers increasing by about 6.9 million birds compared to breeding populations. Most of this increase was accounted for by species that also bred in the region and that considerably increased their abundance (65.6% of all wintering birds, with the Chaffinch Fringilla coelebs responsible for 31.4% of the total increase) and by five exclusively wintering species (34.4%, with the Meadow Pipit Anthus pratensis accounting for 25.2% of the total increase). The main bulk of this increase is caused by the influx of European migrants. The importance of halting the current spread of eucalypt plantations (which increased over 400% over the past 30 years) and of applying more effective agri-environment schemes to achieve appropriate farmland conservation is discussed.

The widespread decline of farmland birds is a major issue of biological conservation in European countries. The Barn Swallow Hirundo rustica is a flagship species for farmland bird conservation owing to its aesthetic and cultural value and to the sharp decline observed in several populations. Based on a long-term monitoring project of a population in a protected area of Northern Italy, we documented a dramatic decline of 56.6% between 1999 and 2011, corresponding to a decrease of 6.59% each year. We also showed that colonies were on average larger in farms with livestock than those without livestock, and that colony size increased with increasing extent of hayfields within 200 m from the colony in farms without livestock, but not in those with livestock. Hayfield extent at greater distances did not influence population size or trend. Cessation of livestock farming therefore determined a decline in local colonies, but this decline may be buffered by an increase in hayfield extent within 200 m from the farm. However, variation in the ecological features of breeding sites explained only a fraction of the observed population decline, suggesting that ecological conditions during migration and wintering may be crucial in affecting population trends. Mean hatching date of first broods advanced in recent years, but less so in farms with, than without, livestock. Independently of year, mean hatching date advanced more in farms with greater extent of hayfields within 200 m of the colony. Reproductive success, measured as the mean number of fledged offspring per nest, declined significantly with hatching date, but was not affected by hayfield extent. Conversely, nestling quality, in terms of body mass and feather development, improved with increasing extent of hayfields around the colony, particularly in late-hatched first clutches. Our findings suggest that conservation strategies for this declining species should include both the maintenance of livestock farming and the enlargement of hayfields close to breeding colonies, particularly in farms where livestock farming has ceased.

Understanding habitat selection and assessing habitat quality have an important role in habitat management and prioritisation of areas for protection. However, interpretations of habitat selection and habitat quality can be confounded by social effects such as conspecific attraction. Using 7 years’ data from a well monitored Great Bustard Otis tarda population in Central Europe, we investigated the roles of human disturbance and social cues in display site selection of male Great Bustards Otis tarda. The spatial distribution of displaying males was best predicted by human disturbance. In addition, the number of males attending display sites was strongly correlated to the number of females present and not with disturbance. This suggests that abundance could be a misleading metric for habitat quality in social species. Our results highlight the roles of disturbance and social cues in male habitat choice, and suggest that social factors need to be taken into consideration for management of endangered populations.

The Aquatic Warbler Acrocephalus paludicola is a globally threatened habitat specialist that breeds in open fens in Central and Eastern Europe. Because bush and reed encroachment threaten many suitable breeding areas, habitat management is necessary to maintain the open wetlands that Aquatic Warblers require for nesting. The effectiveness of mowing as habitat management has so far only been assessed by counting the number of singing males. To assess whether mowing also affected vital reproduction parameters, we analysed Aquatic Warbler productivity in the Biebrza National Park, Poland, on plots in four different successional stages after mowing. Our study showed that productivity was lowest in the first year after mowing, but increased to the highest levels in the second year after mowing. The productivity differences between areas at different stages after mowing resulted from differences in nest density, since we found little evidence for an effect of mowing on nest survival or the number of fledglings produced per successful nest. Nest survival was highly variable between years and varied mostly with nest age and nest initiation date. The density of singing males was positively correlated with both the nest density and the number of fledglings produced in an area, suggesting that this simple indicator could be used to rank the quality of Aquatic Warbler habitats. We recommend that in mesotrophic fen mires, such as the Biebrza valley, mowing as habitat management is applied less frequently than every second year.

Sheldgeese of the genus Chloephaga are waterfowl (Anatidae) endemic to mainland South America and the Falkland Islands (Malvinas). Continental populations of three species C. picta, C. poliocephala, and C. rubidiceps breed in Patagonia and Tierra del Fuego and migrate northwards to winter in central Argentina and Chile. These continental populations have declined by > 50% in the past 30 years due to direct hunting to control crop damage and by the introduction of the grey fox Dusicyon griseus to their breeding grounds in Tierra del Fuego. The continental population of C. rubidiceps is critically endangered, estimated to be < 1,000 individuals. While no historic population size estimates exist for C. rubidiceps in its wintering grounds, the breeding population in Tierra del Fuego was estimated to number several thousand individuals in the 1950s. In contrast, the C. rubidiceps population in the Falkland Islands (Malvinas) is non-migratory and stable with > 42,000 individuals, as is the Falkland Islands (Malvinas) population of C. picta leucoptera with > 138,000 individuals. Here we use sequence data from the mitochondrial DNA control region to quantify genetic divergence between insular and continental populations of these two species of sheldgeese. Chloephaga rubidiceps and C. picta showed significant intraspecific differentiation of 1.0% and 0.6%, respectively. In both cases, mainland and insular populations were reciprocally monophyletic and did not share mtDNA haplotypes. These results suggest that the insular and continental populations of C. rubidiceps and C. picta are genetically distinct and that female-mediated gene flow is restricted. We recommend a reevaluation of the threat category status of the continental C. rubidiceps population, under IUCN guidelines. It is necessary to implement urgent actions for the conservation of this critically endangered population.

No published information is available on the foraging ecology and choice of feeding habitat of New Zealand’s rarest breeding bird: the New Zealand Fairy Tern (NZFT) Sternula nereis davisae. To address this gap, we conducted an assessment of the largest remaining breeding population at Mangawhai Harbour, Northland, New Zealand, during the chick-rearing period of the 2010/2011 breeding season. We combined visual tracking of birds with prey surveys and stable isotope analyses, and we present the first quantitative assessment of NZFT foraging. We recorded 405 foraging dives that show NZFT foraging habitat includes the water edges, shallow channels, and pools on the tidal flats of mangrove-lined (Avicennia marina var. resinifera) parts of the estuary; tidal pools on mud- and sandflats in the mid-estuary and lower harbour; the shallow margins of the dredged main channel in the lower harbour; the oxbow lagoons on the sand spit; and coastal shallows. Our study identifies the mangrove-lined highly tidal and shallow mid-estuary and the lagoon on the sand spit as foraging hotspots for the Mangawhai breeding population of the NZFT. The prey survey employed a seine-net sampling method at identified NZFT foraging sites and yielded 4,367 prey-sized fish of 11 species, two of which had not previously been reported in Mangawhai Harbour, as well as numerous shrimps. The most abundant fish were gobies of the genus Favonigobius. Our stable isotope results highlight gobies as the most important prey for NZFT chick rearing, also indicating that flounder Rhombosolea sp. contribute to NZFT diet. We raise the possibility that shrimps may also constitute a substantial diet component for NZFT, potentially providing up to 21% of diet mass for adult birds. While our results provide a first basis to understanding the feeding ecology of NZFT during their breeding season in order to facilitate conservation planning, further research is required to address inter-annual variation and to identify key foraging grounds for this Critically Endangered bird at other breeding sites.

Coastal and inland surveys for the endemic and “Critically Endangered” Madagascar Fish Eagle Haliaeetus vociferoides were conducted in western Madagascar from Antsiranana in the north to Manja in the south during the 2005 and 2006 breeding seasons (May–October). Surveys covered typical Madagascar Fish Eagle habitat: lakes, rivers, mangroves, estuaries, and marine islands within their known distribution. In total, 287 individuals were encountered, including 98 breeding pairs (196 individuals), 23 breeding trios (69 individuals), 15 single adults and seven immature birds. Of these 287 birds, 128 individuals (44.6%) were observed on lakes; 116 (40.4%) in coastal areas, consisting of 103 (35.9%) in mangroves and 13 (4.5%) in estuaries; 32 (11.2%) on marine islands and 11 (3.8%) on rivers. There was an increase between surveys in 1995 and this study in the number of Madagascar Fish Eagles counted, from 222 to 287, and in the number of pairs from 99 to 121. This study confirms that the Madagascar Fish Eagle population is still low due to human persecution (hunting, collection of eggs and nestlings), overfishing and habitat destruction. We recommend monitoring fish eagles annually at the higher concentration sites to evaluate human activities and conducting a population survey every five years throughout western and northern Madagascar.

Eleonora’s Falcon is a long-distance migrant of the Palearctic region. In recent years, the advent of satellite telemetry has enabled a more detailed investigation of the species’s migratory and wintering periods. In this study, we model the distribution pattern of four Eleonora’s Falcons originating from Greece within their wintering grounds in Madagascar with the use of satellite telemetry data and a niche-based technique, Maxent. The model predicted few highly suitable areas for the occurrence of the species, restricted to elevated areas receiving large amounts of precipitation during the wintering period, containing patches of primary and degraded humid submontane forests as well as cultivation. Most of these areas occurred within the previously estimated home ranges of the four falcons, as well as of three falcons from another independent study. Taking into account the ongoing alterations in landscape structure that occur within the eastern rainforest region of Madagascar, we believe that it is imperative to better understand the ecological requirements of Eleonora’s Falcon. To this end, we recommend the application of Maxent in the study of habitat selection of the species that could be further refined with the inclusion of biotic interactions and seasonal resource availability.

We present the results of searches for the Austral Rail Rallus antarcticus in Argentine and Chilean Patagonia between January 1998 and February 2006 and from subsequent visits. We surveyed 58 localities and found the rail in 22, which collectively cover approximately 85 km2 of habitat. A maximum of 175 individuals were detected. This poorly known species was rediscovered in 1998; since then, it has been found in 18 additional localities, providing further data on distribution, habitat and seasonal movements. During the searches, we found that the species faces different threats, such as reduction of wetlands due to cattle grazing, burning and abnormal water management, but also the presence of American mink Neovison vison. However, due to the lack of prior information we conclude that the species should be maintained as Vulnerable.