7 research outputs found
Birds and Mammals of the Lena Delta Nature Reserve, Siberia
The Lena Delta is the largest arctic delta covered entirely by tundra. Protected since 1986, it is one of the richest areas in the Arctic north of 71° N for both species diversity and breeding densities. Between 6 June and 17 August 1997, 16 mammal species and 76 bird species were recorded in the Lena Delta Nature Reserve and the surrounding buffer zone. Several species are new to the region: far-eastern curlew, fieldfare, redwing, arctic warbler, red-breasted flycatcher, and common rat. New breeders are merlin and arctic warbler. These 1997 records, combined with those from earlier studies, give a total of 122 bird species for the region. Of these, 67 have been found breeding at least once. Densities ranging from 245 to 641 birds per km² were recorded in two restricted study areas. Such densities are unusually high north of 70° N for non-colonial breeding birds. Lapland longspur (100-300 individuals/km²), red phalarope (up to 200 ind./km²), and several Calidris species were the most common. Ruddy turnstone and dunlin had densities higher than those previously reported from the Lena Delta and other Siberian sites. Among the shorebirds, spotted redshank, pintail snipe, grey plover, dunlin, and curlew sandpiper may have extended their breeding range or increased in population during the last 15 years. But further evidence is still needed to confirm the westward extension of spectacled eider, long-billed dowitcher, and sharp-tailed sandpiper.Le delta de la Lena est le plus grand delta arctique totalement recouvert de toundra. Protégé depuis 1986, il est l'une des zones les plus riches de l'Arctique au nord du 71° de latitude N., tant par la richesse spécifique que par les densités d'oiseaux nicheurs. Seize espèces de mammifères et 76 espèces d'oiseaux ont été observées dans la Réserve naturelle du delta de la Lena et sa zone périphérique entre le 6 juin et le 17 août 1997. Plusieurs espèces sont nouvelles pour la région: courlis de Sibérie, grive litorne, grive mauvis, pouillot boréal, gobemouche nain et rat surmulot. Les nouvelles espèces nicheuses sont le faucon émerillon et le pouillot boréal. Combinés à ceux d'études plus anciennes, nos résultats portent à 122 le nombre total d'espèces d'oiseaux recensés dans cette région et à 67 celui des espèces s'y étant reproduit au moins une fois. Des densités comprises entre 245 et 641 individus au km² ont été trouvées sur deux zones d'étude restreintes, densités exceptionnelles au nord du 70° de latitude N. pour des espèces non coloniales. Les espèces les mieux représentées sont le bruant lapon (100-300 ind./km²), le phalarope à bec large (jusqu'à 200 ind./km²) et plusieurs espèces de Calidris. Le tournepierre à collier et le bécasseau variable avaient des densités plus fortes que celles précédemment rapportées pour le delta de la Lena et d'autres sites sibériens. Le chevalier arlequin, la bécassine à queue pointue, le pluvier argenté, le bécasseau variable et le bécasseau cocorli font partie des limicoles qui semblent avoir étendu leur aire de distribution ou augmenté leur population durant les 15 dernières années, mais d'autres travaux seront nécessaires avant de confirmer l'extension occidentale de l'eider à lunettes, du limnodrome à long bec et du bécasseau à queue pointue
Modelling the potential non-breeding distribution of Spoon-billed Sandpiper Calidris pygmaea
The Spoon-billed Sandpiper Calidris pygmaea is a ‘Critically Endangered’ migratory shorebird. The species faces an array of threats in its non-breeding range, making conservation intervention essential. However, conservation efforts are reliant on identifying the species’ key stopover and wintering sites. Using Maximum Entropy models, we predicted Spoon-billed Sandpiper distribution across the non-breeding range, using data from recent field surveys and satellite tracking. Model outputs suggest only a limited number of stopover sites are suitable for migrating birds, with sites in the Yellow Sea and on the Jiangsu coast in China highlighted as particularly important. All the previously known core wintering sites were identified by the model including the Ganges-Brahmaputra Delta, Nan Thar Island and the Gulf of Mottama. In addition, the model highlighted sites subsequently found to be occupied, and pinpointed potential new sites meriting investigation, notably on Borneo and Sulawesi, and in parts of India and the Philippines. A comparison between the areas identified as most likely to be occupied and protected areas showed that very few locations are covered by conservation designations. Known sites must be managed for conservation as a priority, and potential new sites should be surveyed as soon as is feasible to assess occupancy status. Site protection should take place in concert with conservation interventions including habitat management, discouraging hunting, and fostering alternative livelihoods.Additional co-authors: Christoph Zockler, Graeme M Buchana
Evaluating the Impact of Headstarting on the Critically Endangered Spoon-Billed Sandpiper <i>Calidris pygmaea</i>
Headstarting is a conservation approach that suggests offering an advantage to a population by improving egg production, survival of embryos and/or juveniles. In this article, we are providing the quantitative data obtained during 10 years for different stages of headstarting (production of eggs per pair, hatching and fledging rates) and the resulting impact (survival to maturity, philopatry rate, sex ratio, apparent survival, growth/decline rate) on the local population of the critically endangered spoon-billed sandpiper. We have shown that headstarting gains are reduced over time from fledging to long-term recruitment to the local breeding population. The possible reasons for this reduction are suggested and discussed. The unexpected finding was a drastic difference in sex ratios of the new recruits, which was about even for headstarting, but strongly male-biased for wild-reared birds. We suggest this happens due to increased mortality of female chicks in nature. We have also shown only headstarting could stop the global decline of the species, particularly once the suggested improvements are implemented and the number of pairs involved is scaled up. Headstarting also had a significant social effect due to the involvement of increasing numbers of people both in the local communities in Chukotka and from many countries on the flyway into searching for marked birds and learning about waders, raising awareness about ecological problems on the East Asian–Australasian Flyway. Thus, it has made the need for conservation actions on the flyway more obvious and sensible
The intertidal wetlands of southern Jiangsu Province, China – globally important for Spoon-billed Sandpipers and other threatened waterbirds, but facing multiple serious threats
The Yellow Sea region is of high global importance for waterbird populations, but recent systematic bird count data enabling identification of the most important sites are relatively sparse for some areas. Surveys of waterbirds at three sites on the coast of southern Jiangsu Province, China, in 2014 and 2015 produced peak counts of international importance for 24 species, including seven globally threatened and six Near Threatened species. The area is of particular global importance for the 'Critically Endangered' Spoon-billed Sandpiper Calidris pygmaea (peak count across all three study sites: 62 in spring [2015] and 225 in autumn [2014] and 'Endangered' Spotted Greenshank Tringa guttifer (peak count across all three study sites: 210 in spring [2014] and 1,110 in autumn [2015]). The southern Jiangsu coast is therefore currently the most important migratory stopover area in the world, in both spring and autumn, for both species. Several serious and acute threats to waterbirds were recorded at these study sites. Paramount is the threat of large-scale land claim which would completely destroy intertidal mudflats of critical importance to waterbirds. Degradation of intertidal mudflat habitats through the spread of invasive Spartina, and mortality of waterbirds by entrapment in nets or deliberate poisoning are also real and present serious threats here. Collisions with, and displacement by, wind turbines and other structures, and industrial chemical pollution may represent additional potential threats. We recommend the rapid establishment of effective protected areas for waterbirds in the study area, maintaining large areas of open intertidal mudflat, and the urgent removal of all serious threats currently faced by waterbirds here