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Several populations of Pied Avocet are understood to overlap in East Africa, yet the specific movements and size of each of them remains largely unclear. A review of current literature, combined with waterbird counts and recent citizen science data, suggests that potentially three populations occur in the region (Palaearctic, southern origin, and resident), and that the resident population is substantially smaller than previous estimates suggested. A new breeding record at the Kenyan coast, which only constitutes the fourth confirmed breeding location of Pied Avocet in Kenya and the first for the East African coast, demonstrates a potential overlap of Palaearctic migrants and East African residents, which may breed opportunistically along the coast. More resources are needed to carry out standardized and regular national monitoring counts in order to further elucidate the origin, movement, and numbers of Pied Avocets in East Africa. [ABSTRACT FROM AUTHOR]

The Central Valley of California provides important breeding habitat to numerous species of wetlanddependent birds, despite the loss of over 90% of naturally occurring wetlands. A majority of shorebirds breeding in this region rely on shallowflooded habitat adjacent to sparsely vegetated uplands as provided by rice (Oryza sativa), managed wetlands, and other habitats. We estimated the current extent of potential breeding shorebird habitat provided by rice and managed permanent and semi-permanent wetlands in each of four major planning regions of the Central Valley, and estimated the average breeding densities and current population sizes of two species of shorebirds: the Black-necked Stilt (Himantopus mexicanus) and American Avocet (Recurvirostra americana). Using a population status framework based on principles of conservation biology, we estimated that stilt populations are small (<10,000 individuals) or very small (<1,000 individuals) in three of the four planning regions, and avocet populations are small or very small in all four planning regions. We then used the framework to define long-term (100-year) population objectives for stilts, avocets, and a third species, Killdeer (Charadrius vociferous), designed to meet our long-term conservation goal of supporting self-sustaining, genetically robust, and resilient populations of breeding shorebirds in the Central Valley. We also estimated the long-term density objectives and wetland habitat objectives necessary to achieve the population objectives for all three species. The corresponding short-term (10-year) conservation objectives are to restore permanent and semi-permanent wetlands to provide an additional 11,537 ha (28,508 ac) of habitat for breeding shorebirds (by planning region: 2,842 ha in Sacramento, 2,897 ha in Yolo-Delta, 2,943 ha in San Joaquin, and 2,855 ha in Tulare), and to enhance existing habitat to support density objectives. Our approach provides a transparent, repeatable process for defining science-based conservation objectives for breeding shorebirds and their habitats in the Central Valley, which can help unite stakeholders around common goals and motivate conservation actions. [ABSTRACT FROM AUTHOR]

An episode of mortality in waterbirds occurred on a sedimentation reservoir with effluents from the sugar beet processing plant at Hrusovany n.J. (South Moravia, Czech Republic) in summer 2003: tens of black-headed gulls (Larus ridibundus), several lapwings (Vanellus vanellus), one little ringed plover (Charadrius dubius), one ruff (Philomachus pugnax), one wood sandpiper (Tringa glareola), and two avocets (Recurvirostra avosetta) died. One of the two avocets and the plover, local breeders, were examined and found positive for Clostridium botulinum type C toxin by use of the toxin-neutralization test. Avocet is classified as a rare bird species according to Red Book data and is listed as critically endangered species in theCzechRepublic, and is therefore protected. Avian botulism can occasionally cause deleterious effects to waterbird fauna and its protection.

Absent as a breeding bird from Britain for at least a century, avocets (Recurvirostra avosetta) began nesting on the east coast of Britain, in Suffolk, shortly after the end of the Second World War, having homed in on two spots on Britain’s coast that had been flooded for war-related reasons. The avocets’ presence was surrounded in secrecy, while a dedicated few kept up a protective watch over them. As the Royal Society for the Protection of Birds (RSPB) took over responsibility for the flourishing colony, they claimed the episode as a symbol of success for British protection, later making the bird their logo. Counter to the RSPB’s story of protecting a British bird, I read the narratives of events in terms of making a bird British. I show how, as postwar Britain slumped economically and spiritually and tried to rebuild itself, the birds became a vehicle for formulating national identity: of Britain as a home to which to return and belong. Exploring the themes of returning servicemen and closed territories, the paper also examines the episode in terms of the naturalisation of the military and the militarisation of nature. [Copyright &y& Elsevier]

Predators that feed on clustered prey tend to have an ‘area-restricted search’ (ARS), characterized by a combination of a slow and tortuous movement in prey-rich areas, and a fast and straight movement in poorer areas. Waders that forage in intertidal areas usually prey upon buried macroinvertebrates, whose distribution is often clustered. However, wader species differ in the strategy used to find their prey: some rely mainly on visual cues, some rely on tactile cues, and others follow a more generalist method, simply sweeping the sediment surface with the bill. We hypothesized that these strategies influence the adoption of an ARS by waders. We analysed this hypothesis by comparing the fine-scale movement of a ‘tactile’ predator (black-tailed godwit, Limosa limosa), with that of a ‘visual’ predator (redshank, Tringa totanus) and a ‘sweeper’ (avocet, Recurvirostra avosetta). We filmed 190 individuals of the three species and, using GIS facilities, obtained more than 12 000 spatial positions, along with detailed records of feeding activity. We analysed several parameters of fine-scale movement of waders, such as foraging and searching speeds, tortuosity, and the relationship between these parameters and foraging success. Only the tactile predator, the black-tailed godwit, followed an ARS, reducing searching speed and increasing spatial turning rate whenever the prey intake was higher. Furthermore, its foraging strategy involved short-term adjustments of movement that maximized the likelihood of finding subsequent prey, suggesting a prior knowledge or an ability to perceive rapidly the distribution pattern of its prey. [Copyright &y& Elsevier]

Excess selenium (Se) in the aquatic food chain is embryotoxic and teratogenic to avocets, stilts, and other waterbirds. American avocet (Recurvirostra americana) and black-necked stilt (Himantopus mexicanus) eggs were collected from three sites in the Tulare Lake Basin of California, USA, and hatched in the laboratory. These sites included the Tulare Lake Drainage District--north (TLDD-N, water 2.5 ppb Se), TLDD--south (TLDD-S, water 8.6 ppb Se), and Westfarmers (WF, water 190 ppb Se). Highest egg Se concentrations occurred at WF (geometric mean 31.4 ppm dry wt for avocets and 20.5 ppm dry wt for stilts). Mean egg Se concentrations were 6.7 ppm for avocets and 8.4 ppm for stilts at TLDD-S, and 3.3 ppm for avocets and 2.3 ppm for stilts at TLDD-N. Hatching success and incidence of malformations did not differ among sites, but yolk sac--free hatching weights and bone lengths were less for avocets at the WF site, whereas liver weights and liver to body weight ratios were greater at that site. With increasing Se concentration, oxidative stress was most apparent in avocet hatchlings from WF: hepatic glutathione (GSH) peroxidase activity increased, glucose-6-phosphate dehydrogenase activity decreased, and oxidized glutathione (GSSG) concentration as well as the ratio of GSSG to reduced GSH concentration increased. In stilts, hepatic GSH concentration was lower in WF hatchlings. In conclusion, our findings of Se-impaired embryo growth and hepatotoxicity in avocet hatchlings suggest that oxidative stress observed in hatchlings may be related to these biological effects and may serve as a potential bioindicator of subsequent impaired functions. [ABSTRACT FROM AUTHOR]

1. The European soda pans of the Carpathian Basin provide important stopover sites for several waterbird species. We studied the effect of different invertebrate food types and other characteristics on the habitat choice and distribution of birds on 82 pans (in Hungary, Austria and Serbia) during spring migration. 2. Only three environmental variables proved to be significant determinants of the waterbird communities: pan density (spatial effect) along with the density of Arctodiaptomus spp. and anostracans (local effect). Variance partitioning of the data revealed that aquatic invertebrate food supply ( Arctodiaptomus and anostracans) had a greater effect than pan density on the 10 investigated bird species, suggesting a dominant role of species sorting in structuring the communities. Pied avocets ( Recurvirostra avosetta) and northern shovelers ( Anas clypeata) differed from the other species in their strong association with densities of anostracans (avocet) and Arctodiaptomus (shoveler). 3. Anostracans and microcrustaceans, especially the most frequent Branchinecta orientalis, Arctodiaptomus spinosus and Arctodiaptomus bacillifer, can be regarded as keystone elements of this soda pan habitat because of their bottom-up role in structuring waterbird assemblages during spring migration. [ABSTRACT FROM AUTHOR]

Little is known about the biology of waders wintering in southern Asia; this paper deals with the Grey Plover Pluvialis squatarola, a species extensively studied only in western Europe. Adult Grey Plovers wintering in southeastern India underwent primary moult in autumn; theduration was estimated to be 127 days, with mean starting date 1 September and mean completion date 5 January. Some first-year Grey Plovers initiated primary moult in late winter and spring, and completed this moult the following spring. The average mass of adults on arrivalin September was 200 g, fluctuated close to 220 g from October to February, and increased to 280 g near the end of May. The mass variation did not show the January peak observed in western Europe. Breeding productivity, measured as the percentage of first-year birds in winter catches, varied between 5% and 70% over six years, and showed a positive correlation with that of Dark-bellied Brent Geese Branta b. bernicla in western Europe and Curlew Sandpipers Calidris ferruginea in South Africa. [ABSTRACT FROM AUTHOR]