Spoon-billed Sandpiper Research Articles

Population decline in the spoon-billed sandpiper (Eurynorhynchus pygmeus) in northern Chukotka based on monitoring on breeding grounds

The spoon-billed sandpiper is endemic of the northern Russian Far East and one of the rarest wader species in the world. During a field survey (summer 2002) of the coast of Kolyuchinskaya Bay and in lagoons located to the east, it was discovered that the species breeding population has declined by 3–5 times since the 1970s and amounted to only 42–50 breeding pairs. The reasons for this decline are uncertain. They seem to occur outside the breeding grounds, on staging or wintering areas in South Eastern Asia. The breeding productivity of the spoon-billed sandpiper is relatively low, but it did not decrease in recent decades. The breeding success in 2002 was higher than in the 1980s; however, it was still about half of the minimum level necessary to keep the local breeding population stable. Annual survival of the spoon-billed sandpiper is about 5–15% lower than in several other small Calidridinae waders. An increased mortality rather than decreased productivity appears to be responsible for the general decline of the spoon-billed sandpiper population. In the early 2000s, its total world population was estimated at 350–500 breeding pairs. The estimate of the spoonbilled sandpiper population obtained by Flint and Kondratyev (1977) is likely an overestimate.

Rapid and continued population decline in the Spoon-billed Sandpiper Eurynorhynchus pygmeus indicates imminent extinction unless conservation action is taken

SummaryThe 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.

A Bird’s-Eye View of Arctic Governance: Reflecting on the Role of International Law in Arctic Cooperation from a Bird Conservation Perspective

Abstract This article discusses the role of international law in environmental governance in the Arctic. It does so from the perspective of bird conservation. Challenges in the latter field are introduced, including the impact of climate change on Arctic bird habitats and the incidental mortality of seabirds in Arctic fisheries. The ability of the current international legal framework in the Arctic to meet these challenges is scrutinised, and future scenarios for its enhancement are explored, including the conclusion of (a) new legally binding agreement(s). Five species receive particular attention as part of this exercise: gyrfalcon (Falco rusticolus), ivory gull (Pagophila eburnea), spoon-billed sandpiper (Eurynorhynchus pygmeus), Kittlitz’s murrelet (Brachyramphus brevirostris) and Brünnich’s guillemot (Uria lomvia). Special attention is also devoted to the issue of seabird bycatch.

The effects of benthos and wetland area on shorebird abundance and species richness in coastal mangrove wetlands of Leizhou Peninsula, China

Twenty-two species shorebirds were recorded on mangrove wetlands surrounding Leizhou Peninsula, Guangdong Province, China. One recorded species, Spoon-billed Sandpiper ( Eurynorhynchus pygmeus), is listed as endangered in the IUCN Red List (World Conservation Union) and this was the first record of the species at Leizhou in this study. Most recorded species are listed in the Sino-Japan or Sino-Australia Agreement on Conservation of Migratory Birds. Dunlin ( Calidris alpina), Kentish Plover ( Charadrius alexandrinus), and Greater Sand Plover ( Charadrius leschenaultii) were dominant, accounting for 34%, 32%, and 12% of total individuals, respectively. Five survey sites were designated by habitat type. There was no significant difference in species, but total abundance differed significantly among survey sites. More species were recorded in winter and spring than in summer. One hundred and sixty-five species of benthos were recorded. Total mean biomass and density of benthos was 223.3 ± 74.8 g/m 2 (±S.E.), density 210.97 ± 67.6 ind./m 2, respectively. Mollusks accounted for 83.4% of total biomass, and 75.6% of total density. Both biomass and density of benthos varied significantly among survey sites. There was no significant difference between spring and autumn on biomass or density of benthos. There was a significant and negative correlation between number of shorebirds and densities of polychaetes on mudflats. Shorebird species richness ( F 1,3 = 13.14, p = 0.036) and abundance ( F 1,3 = 12.59, p = 0.037) were significantly and positively correlated with mudflat area. Stopping losses of mangrove habitat and tidal flats is the top priority measure for shorebird conservation. Reducing the impacts of human disturbance on both habitats and birds is an urgent necessity for mangrove wetland conservation management.

Status and Conservation of Shorebirds in the East Asian-Australasian Flyway

This publication comprises the proceedings of the Australasian Shorebirds Conference held in Canberra in 2003. It is No. 18 of Wetlands International Global Series and International Wader Studies 17 of the International Wader Study Group. Although publication was delayed, the papers in this proceedings remain an important contribution to international shorebird conservation. Eighteen of the 25 papers are about Australian and New Zealand shorebirds, while the remainder are mainly from Southeast Asia. Topics include managing human disturbance of plovers on Australian beaches, conservation of the Spoon-billed Sandpiper Eurynorhynchus pygmaeus in Russia, shorebird studies in Taiwan, and threats from marine farming in New Zealand.

A comparison of the sustainability of original and constructed wetlands in Yancheng Biosphere Reserve, China: implications from emergy evaluation

Yancheng Biosphere Reserve (YBR) is located along the coastal zone of the Yellow China Sea with 900 km long in Jiangsu Province. Human activities have greatly interfered the original wetlands in YBR for migratory birds using this region as the Flyway with rapidly economic development since 1980. Much of the experimental zones and buffer zones are transferred to agriculture, aquaculture, transportation or buildings, etc. which directly results in many birds losing their habitats and becoming globally threatened, such as the Spotted Greenshank (Tringa guttifer) and the Spoon-billed Sandpiper (Eurynorhynchus pygmeus). So since 1993 some constructed wetlands have been created in the core zone of YBR in order to protect those threatened and near-threatened shorebirds. How to evaluate the sustainability of these original and constructed wetlands is a concern to managers, scientists and local stakeholders. This paper is an initial study on emergy evaluation of original wetlands and recently constructed wetlands in YBR, China. Two new emergy indices, base emergy change (Bec) and net profit (Np), are presented in order to compare the ecological-economic benefits of these different kinds of wetlands. Results show that a waterfowl pond, constructed for ecological reasons at the edge of the core zone of YBR, has much more Bec than the original wetlands and fishponds, while its Np is negative and much lower than the other sites. Fishponds built for economic reasons in the buffer zone have negative Bec while their Np is the highest. However, the emergy yield ratio (Yr) of the original wetlands is the highest. The constructed waterfowl pond can draw more coastal birds than before. Likewise the constructed fishponds can win large economic benefits to maintain the feedback to the waterfowl pond. But no more fishponds should be constructed due to the highest emergy yield ratio of the original wetlands and high Bec in the waterfowl pond. Finding the best way to harmonize conservation and development in the YBR is of great importance to a sustainable future.

Yubu Island, the Important Waterbird Habitat on the West Coast of Korea and Its Conservation

Yubu Island is located within the estuary of the Geum River, South Chungcheong Province <TEX>$(35^{\circ}59'N,\;126^{\circ}36'E)$</TEX>, Korea. The island is surrounded by a broad and sandy mudflat, which is typical in the west coast of Korea, and is located 4km off from Gunsan City. Less than 100 humans live on the island, occupying 30 houses. After we discovered that this island was a very important waterbird habitat especially for the East Asian subspecies of the Eurasian oystercatcher, Haematopus ostralegus osculans. Waterbirds were monitored once every month from August 1999 to July 2000. The highest number of oystercatchers counted was 3,200 in December 1999, and the birds seemed to remain in the area continuously from September to next February. About 200 breeding and non-breeding birds remained during the breeding season. In August, early migrants returned to the island, with the number reaching 1,060 individuals. This island is also very important for other waterbirds. Endangered or significant species occurring at this site, and their maximum counts were: chinese egret Egretta eulophotes (5), black-faced spoonbill Platalea minor (17), brant Branta bernicla (1), common shelduck Tadorna tadorna (8,000), hooded crane Grus monacha (2), spoon-billed sandpiper Ewynorhynchus pygmeus (7), dunlin Calidris alpina (6,500), great knot Calidris tenuirostris (24,000), far eastern curlew Numenius madagascariensis (2,500), spotted greenshank Tringa guttifer (4) and Saunders's gull Larus saundersi (1,200). During the 12 month survey period, we observed 52 waterbird species and the total of the maximum counts for the separate species was 73,308, implying that perhaps 150,000 birds could be using the immediate area, if a turnover rate of 2 was assumed.

First indications of a sharp population decline in the globally threatened Spoon-billed Sandpiper Eurynorhynchus pygmeus

Spoon-billed Sandpiper Eurynorhynchus pygmeus is classed as globally Vulnerable, based on the only available population estimate, made in 1977, of 2,000–2,800 pairs. Surveys for breeding Spoon-billed Sandpipers were carried out in summer 2000 on the Anadyr estuary coast, the Chukotka autonomous region, Russia. Although six new breeding sites were found, only 16–17 breeding males/pairs were recorded on the northern coast of the Anadyr estuary and five males/pairs on the southern coast and more southerly lagoons. These numbers were much lower than expected, and the species was not recorded in several apparently suitable areas. Four formerly known breeding sites held only one displaying male between them. At no site was there evidence of an increasing or stable local population. Together with other indicative data these suggest a sharp decline in the population of Spoon-billed Sandpiper. The previous population size estimate obviously requires updating, both because there were some incorrect assumptions in the calculations made for the first population estimate, and also due to a recent population decline. It is likely that the current population numbers under 1,000 breeding pairs. Given that the population of this species may be substantially lower than the only previous estimate, and the evidence for a possible rapid decline in its population described in this paper, it is recommended that its IUCN status is changed from Vulnerable to Endangered. No reasons for the apparent rapid rate of decline are evident within the breeding range. “Bottle-necks” should be looked for at migration sites or wintering grounds, but currently, monitoring of the population is only possible on the breeding grounds.

A new pressure sensory mechanism for prey detection in birds: the use of principles of seabed dynamics?

We demonstrate a novel mechanism for prey detection in birds. Red knots (Calidris canutus), sandpipers that occur worldwide in coastal intertidal areas, are able to detect their favourite hard-shelled prey even when buried in sand beyond the reach of their bills. In operant conditioning experiments designed to find out whether the birds could tell buckets containing only wet sand from buckets containing hard objects in wet sand, we show that they detect the presence not only of deeply buried live bivalves but also of stones. The latter finding virtually excludes, under experimental conditions, prey-detection mechanisms based on vision, acoustics, smell, taste, vibrational signals emitted by prey, temperature gradients and electromagnetic fields. A failure to discriminate between food and non-food trays with dry sand indicates that pore water is involved. Based on the presence of large arrays of Herbst corpuscles (sensory organs that can measure the acceleration due to changes in pressure), the specifics of foraging technique and the characteristics of sediments on which red knots feed, we deduce that the sensory mechanism involves the perception of pressure gradients that are formed when bills probe in soft sediments in which inanimate objects block pore water flow. To our knowledge, this mechanism has not been described before. It is argued that repeated probing in soft, wet sediments allows red knots to induce a residual pressure build-up of sufficient strength to detect the pressure disturbance caused by a nearby object. The cyclic process of shaking loosely packed sand grains followed by gravitational settling into a closer packing, leads, owing to insufficient drainage of the sediment, to a locally increased pressure disturbance that is 'pumped up' at each shake.

Additional records of the Spoon-billed Sandpiper Eurynorhynchus pygmaeus from Hokkaido

Additional records of the Spoon-billed Sandpiper Eurynorhynchus pygmaeus from Hokkaido

Comparative anatomy of head and neck in the Spoon‐billed sandpiper, Eurynorhynchus pygmeus and its allies

Head and neck anatomy is described and compared in the Spoon‐billed sandpiper Eurynorhynchus pygmeus, the Rufous‐necked stint Calidris ruficollis and the Broad‐billed sandpiper Limicola falcinellus (Calidritinae). Eurynorhynchus pygmeus closely resembles Calidris ruficollis (typical of the subfamily) in most aspects other than bill form. Information on feeding behaviour is summarized. It is concluded that the expanded bill of Eurynorhynchus pygmeus functions chiefly to increase its capacity for tactile detection of prey. The suggestion of close relationship between Eurynorhynchus pygmeus and Limicola falcinellus is rejected.

The Nesting Grounds and Nesting Habits of the Spoon-Billed Sandpiper

The Nesting Grounds and Nesting Habits of the Spoon-Billed Sandpiper

X. On the Osteology and Pterylosis of the Spoon-billed Sandpiper (Eurynorhynchus pygmaeus, Linn.).

X. On the Osteology and Pterylosis of the Spoon-billed Sandpiper (Eurynorhynchus pygmaeus, Linn.).