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We isolated a high pathogenicity avian influenza (HPAI) virus from a common pochard (Aythya ferina) that was being attacked by a bird of prey in South Korea in December 2020. Genetic analyses indicated that the isolate was closely related to the clade 2.3.4.4b H5N8 HPAI viruses found in South Korea and Japan during the winter season of 2020–2021. The histopathological examination revealed multifocal necrotizing inflammation in the liver, kidney, and spleen. Viral antigens were detected in the liver, kidney, spleen, trachea, intestine, and pancreas, indicating the HPAI virus caused a systemic infection. The presence of immunoreactivity for the viral antigen was observed in the cells involved in multifocal necrotic inflammation. Notably, epitheliotropic-positive patterns were identified in the epithelial cells of the trachea, mucosal epithelium of the intestine, and ductular epithelium of the pancreas. These findings provide direct evidence supporting the possibility of HPAI transmission from infected waterfowl to predators. Detectado en el acto: Aislamiento y caracterización de un virus de la influenza aviar de alta patogenicidad del clado 2.3.4.4b H5N8 de un porrón común (Aythya ferina) atacado por un halcón peregrino (Falco peregrinus). Se aisló un virus de la influenza aviar (HPAI) de alta patogenicidad de un porrón común (Aythya ferina) que estaba siendo atacado por un ave rapaz en Corea del Sur en diciembre de 2020. Los análisis genéticos indicaron que el aislado estaba estrechamente relacionado con virus de influenza aviar de alta patogenicidad H5N8, clado 2.3.4.4 b encontrados en Corea del Sur y Japón durante la temporada de invierno de 2020–2021. El examen histopatológico reveló inflamación necrotizante multifocal en hígado, riñón y bazo. Se detectaron antígenos virales en el hígado, el riñón, el bazo, la tráquea, el intestino y el páncreas, lo que indica que este virus de alta patogenicidad causó una infección sistémica. Se observó la presencia de inmunorreactividad para el antígeno viral en las células involucradas en la inflamación necrótica multifocal. En particular, se identificaron patrones epiteliotrópicos positivos en las células epiteliales de la tráquea, el epitelio mucoso del intestino y el epitelio ductular del páncreas. Estos hallazgos proporcionan evidencia directa que respalda la posibilidad de transmisión de HPAI de aves acuáticas infectadas a especies depredadoras. [ABSTRACT FROM AUTHOR]

Data on Common Pochard (hereafter Pochard) migration was taken from the Database of the Bird Ringing Centre of Russia. Data on weather conditions in the day of recovery and dates of the transitions through 0, 5 and 10°C were obtained from the climate site http://pogoda-service.ru/archive%5fgsod.php. After all filtering, we used 575 Pochard recoveries that are valid for the treating weather-dependence of Pochards on the spring arrival. In addition to the common known ways of analysis, we use so called "ecological fingerprints" (Kharitonov et al., 2022). For the entire breeding range, the average date of arrival of the Pochard is 4 May (Julian date is 124.87 ± 0.61 days N = 575), most recoveries are concentrated around this average date. In the westernmost parts of the considered breeding range in spring, Pochards perform break-through migration, when birds in some areas in eastern parts of the breeding range appeared later than in western ones. Secondly coming birds fly not so fast, their style of migration can be called as steady migration. Three parameters are important for arrival time: latitude of recovery, Julian date of recovery, and mean daily temperature. The Julian date of arrival is more important for Pochards than mean daily temperature. In the southern areas of the western part of the breeding range, Pochards are not much limited by climatic conditions. Pochards are guided not only by the approach of spring events, but also by some specific day of the year, represented by the Julian date. In the northern areas of the western parts and in the entire eastern part of the breeding range, a compromise is seen between the Julian date of the season (Pochards tend to arrive earlier) and mean daily temperature (they have to arrive later). [ABSTRACT FROM AUTHOR]

We purposed in this paper to show the coenotic affinities established between the species of birds directly dependent on waters, observed on some dam basins from ROSPA0062 - The dam basins from the Argeş River during the autumn migratory season of 2013, which correspond to the serotinal and autumnal ecologically seasons, when the majority of the migratory birds appear through the area. Aythya ferina and Anas platyrhynchos were the most characteristic species from the coenotic affinity point of view for the whole series of the researched reservoirs, while Larus ridibundus and Podiceps cristatus were the most characteristic species for Vâlcele Dam Basin, Anas platyrhynchos and Aythya ferina, for the Budeasa Dam Basin, Anas platyrhynchos and Phalacrocorax carbo, for the Bascov Dam Basin, Aythya ferina and Cygnus olor, for the Piteşti Dam Basin, and, again, Aythya ferina and Anas platyrhynchos, for the Goleşti Dam Basin. The generally different pairs of characteristic species highlight once more the different life conditions for the birds from every dam basin, that are influenced by the succession of these reservoirs on the river course, the type of habitats, the human pressure, etc. Also, other considerations about the phenology of the species and the similarity between the avicoenoses of the taken into study dam basins are done in the paper. [ABSTRACT FROM AUTHOR]

The habitat suitability for the Common Pochard, a duck species in decline, was studied in the middle reaches of the Orel’ River, Central Ukraine, in 2015–2017. The ducks were counted on their breeding grounds with the use of the ground survey technique. The positions of individual birds were estimated by GPS and plotted on the Google Earth map. The Ecological Niche Factor Analysis (ENFA) was applied to assess the habitat suitability. Sentinel-2 image was used to extract 13 ecogeographical variables and to get two measures of the ecological niche (marginality and specialization). The ENFA procedure was applied twice at landscape and sub-landscape levels to describe the habitat selection across sequential spatial scales. Both the axes of marginality and specialization of the ecological niche of the species proved to be significantly different from the random alternatives. At landscape level, the distribution may be predicted with the use of Aerosol/Coastal, Vegetation and Hydrothermal Composite indices (marginality) and Modified Normalized Difference Water (MNDW) Index along with several vegetation indices (specialization). At sub-landscape level, MNDW played a crucial role. The importance of MNDW is mediated by the preference for the wetlands with the stretches of open water which are used by the ducks to initiate flight safely and to optimize diving possibilities. The ENFA is a reliable tool for the assessment of the habitat suitability and for setting the conservation priorities for the Common Pochard.

Assessing trends in the relative abundance of populations is a key yet complex issue for management and conservation. This is a major aim of many large‐scale censusing schemes such as the International Waterbird Count (IWC). However, owing to the lack of sampling strategy and standardization, such schemes likely suffer from biases due to spatial heterogeneity in sampling effort. Despite huge improvements of the statistical tools that allow tackling these statistical issues (e.g., GLMM, Bayesian inference), many conservationists still prefer to rely on stand‐alone turn‐key statistical tools, often violating the prerequisites put forward by the developers of these tools. Here, we propose a straightforward and flexible approach to tackle the typical statistical issues one can encounter when analyzing count data of monitoring schemes such as the IWC. We rely on IWC counts of the declining common pochard populations of the Northwest European flyway as a case study (period 2002–2012). To standardize the size of sampling units and mitigate spatial autocorrelation, we grouped sampling sites using a 75 × 75 km grid cells overlaid over the flyway of interest. Then, we used a hierarchical modeling approach, assessing population trends with random effects at two spatial scales (grid cells, and sites within grid cells) in order to derive spatialized values and to compute the average population trend at the whole flyway scale. Our approach allowed to tackle many statistical issues inherent to this type of analysis but often neglected, including spatial autocorrelation. Concerning the case study, our main findings are that: (1) the northwestern population of common pochards experienced a steep decline (4.9% per year over the 2002–2012 period); (2) the decline was more pronounced at high than low latitude (11.6% and 0.5% per year at 60° and 46° of latitude, respectively); and, (3) the decline was independent of the initial number of individuals in a given site (random across sites). Beyond the case study of the common pochard, our study provides a conceptual statistical framework for estimating and assessing potential drivers of population trends at various spatial scales. [ABSTRACT FROM AUTHOR]

Abstract Background The Common Pochard (Aythya ferina) (hereafter Pochard), a widespread and common freshwater diving duck in the Palearctic, was reclassified in 2015 from Least Concern to Vulnerable IUCN status based on rapid declines throughout its range. Analysis of its status, distribution and the potential causes for the decline in Europe has been undertaken, but there has never been a review of its status in the major part of its breeding range across Russia to the Pacific coast. Methods We reviewed the scientific literature and unpublished reports, and canvassed expert opinion throughout Russia to assess available knowledge about changes in the species distribution and abundance since the 1980s. Results While accepting available information may not be representative throughout the entire eastern range of the species, the review found marked declines in Pochard breeding abundance in the last two decades throughout European Russia. Pochard have also declined throughout Siberia. Declines throughout the steppe region seemed related to local drought severity in recent years, necessitating further research to confirm this climate link at larger spatial scales. Declines in the forest and forest-steppe regions appeared related to the major abandonment of fish farms in western Russia that had formerly provided habitat for breeding Pochard. However, hyper-eutrophication of shallow eutrophic lakes, cessation of grazing and haymaking in floodplain systems necessary to maintain suitable nesting habitat and disappearance of colonies of the Black-headed Gull (Chroicocephalus ridibundus) in a number of wetlands were also implicated. Increasing invasive alien predator species (e.g. American Mink Neovison vison and Raccoon Dog Nyctereutes procyonoides) and increasing spring hunting were also thought to contribute to declines. Reports of expansion in numbers and range only came from small numbers occurring in the Russian Far East, including on the border with China and the long-established isolated population on Kamchatka Peninsula. Conclusions Widespread declines throughout the eastern breeding range of the Pochard give continued cause for concern. Although we could address all the potential causal factors identified above by management interventions, we urgently need better information relating to key factors affecting site-specific Pochard breeding success and abundance, to be able to implement effective actions to restore the species to more favourable conservation status throughout its breeding range.

Fishponds constitute a major breeding habitat for the common pochard Aythya ferina in Europe. This study explored possible causes of its recent decline, in describing the consequences of diverse pond management options in Brenne, central France. Pair density and the brood:pair ratio were described in a pond sample under varying management practices, in the early 2000s and, again, a decade later. The influence of pond management on these variables was studied by model comparisons. In the early 2000s, 69.5% of the studied ponds were fertilized by fish farmers. Higher pochard pair densities were observed in those with artificial carp feeding and the brood:pair ratio was positively related to fish biomass density, provided that pair density was not too high. A decade later, only 25% of studied ponds remained fertilized. Pochard pair density was positively correlated with fish biomass density. But lower brood:pair ratios were recorded in ponds with artificial carp feeding, due to the fact that higher pair density there did not lead to increased brood density. Between the two study periods, the pair number remained stable in the sample but the brood:pair ratio decreased, from 0.84 to 0.71. Our results support the idea that habitat conditions that enable high fish productivity were also attractive for pochard pairs. They suggest the hypothesis that pond fertilization for enhancing primary productivity and, thereby, fish biomass, may also favour pochard breeding success. We must however bear in mind that, even with active fish farming management, fish biomass density in French fishponds remains usually moderate when compared to those in central Europe. The study did not reveal any effect of hunting management since waterfowl feeding, predator control or mallard release did not significantly influence either pond use by pochard pairs or the brood:pair ratio. [ABSTRACT FROM AUTHOR]

Background: The Common Pochard (Aythya ferina) (hereafter Pochard), a widespread and common freshwater diving duck in the Palearctic, was reclassified in 2015 from Least Concern to Vulnerable IUCN status based on rapid declines throughout its range. Analysis of its status, distribution and the potential causes for the decline in Europe has been undertaken, but there has never been a review of its status in the major part of its breeding range across Russia to the Pacific coast. Methods: We reviewed the scientific literature and unpublished reports, and canvassed expert opinion throughout Russia to assess available knowledge about changes in the species distribution and abundance since the 1980s. Results: While accepting available information may not be representative throughout the entire eastern range of the species, the review found marked declines in Pochard breeding abundance in the last two decades throughout European Russia. Pochard have also declined throughout Siberia. Declines throughout the steppe region seemed related to local drought severity in recent years, necessitating further research to confirm this climate link at larger spatial scales. Declines in the forest and forest-steppe regions appeared related to the major abandonment of fish farms in western Russia that had formerly provided habitat for breeding Pochard. However, hyper-eutrophication of shallow eutrophic lakes, cessation of grazing and haymaking in floodplain systems necessary to maintain suitable nesting habitat and disappearance of colonies of the Black-headed Gull (Chroicocephalus ridibundus) in a number of wetlands were also implicated. Increasing invasive alien predator species (e.g. American Mink Neovison vison and Raccoon Dog Nyctereutes procyonoides) and increasing spring hunting were also thought to contribute to declines. Reports of expansion in numbers and range only came from small numbers occurring in the Russian Far East, including on the border with China and the long-established isolated population on Kamchatka Peninsula. Conclusions: Widespread declines throughout the eastern breeding range of the Pochard give continued cause for concern. Although we could address all the potential causal factors identified above by management interventions, we urgently need better information relating to key factors affecting site-specific Pochard breeding success and abundance, to be able to implement effective actions to restore the species to more favourable conservation status throughout its breeding range. [ABSTRACT FROM AUTHOR]

Common pochard Aythya ferina are rapidly declining globally, partly due to water quality change at breeding habitats. Lake restoration at two southern Danish lakes (external nutrient loading reduction, bream Abramis brama and roach Rutilus rutilus removal and stocking of pike Esox lucius) improved water clarity and submerged macrophyte cover. Nesting pochard on one lake increased from 2.3 females per annum pre-treatment to 13.9 afterwards and from 22.7 females to 99.6 post-treatment at a second. Numbers fell from 27.7 to 11.3 at a third untreated lake with consistently high water clarity, but which was colonised and became dominated by holly-leaved naiad Najas marina, which provides no food resources for breeding pochard. Linear modelling (controlling for serial autocorrelation) showed statistically significant effects of annual summer measurements of suspended solids (negative) and Secchi depth (positive) on pochard abundance at both restored lakes and chlorophyll (negative) at one of those lakes, but no effects at the third. Breeding pochard numbers also correlated positively with submerged macrophyte cover at one restored lake with adequate data. Results support the hypothesis that lake restoration to improve water quality enhances conditions for locally breeding pochard, as long as restored conditions secure appropriate submerged macrophyte communities for nesting pochard. [ABSTRACT FROM AUTHOR]

From its last report through 2016 the California Bird Records Committee reached decisions on 174 records involving 167 individuals of 68 species and two species groups, endorsing 139 records of 152 individuals. The first accepted state records of the Purple Sandpiper (Calidris maritima), Jouanin's Petrel (Bulweria fallax), and Buff-breasted Flycatcher (Empidonax fulvifrons) are outlined in this report, as is the acceptance of the Oriental Greenfinch (Chloris sinica) to the main list based on reconsideration of a record that was previously not accepted. These additions bring California's total list of accepted species to 667, of which 11 represent established introductions. Other notable records detailed in this report include the state's second Swallow-tailed Kite (Elanoides forficatus), third Great Frigatebird (Fregata minor), and fourth Common Pochard (Aythya ferina). [ABSTRACT FROM AUTHOR]

We used ringed-recoveries to assess: 1) the connectivity (movements of individuals) between the three putative flyways (north-west Europe, central Europe, south-west Asia) of common pochards in the Western Palearctic, 2) possible spatio-temporal variations in the distribution of the species, and, 3) temporal evolution in spring and autumn migration dates. Based on winter counts of common pochards in the north-west European flyway, we distinguished three periods in the analyses (1960-1990, 1991-2000 and 2001-2016), which correspond to successive periods of population increase, peak and decline, respectively. Whatever the season (wintering or breeding) and period of ringing, large probabilities of ring-recoveries outside the flyway of origin (ringing) were recorded, suggesting a high connectivity between the three putative flyways. There was a significant trend towards an earlier departure from the wintering area, and an eastward shift of spring recoveries over periods. In contrast, neither autumn/winter recovery locations, nor departure dates from the breeding area in Latvia and Russia changed over periods. The latter results do not support the hypothesis that shortstopping (i.e. a reduction of fall migration distances/delaying of departure dates from the breeding area) could explain the observed decline of wintering common pochards in the north-west European flyway. Indirect recoveries support that large proportions of individuals wintering in western Europe may originate from the south-west Asia flyway and more particularly from a region in Siberia located in the Ob river catchment area. Considering trends in numbers for the three flyways together confirmed the "vulnerable" IUCN status of common pochard in the Western Palearctic as a whole, with a 35% decline over the last decade. The important connectivity between the northwest, central European and southwest Asian flyways call for considering such conservation problems at a much broader scale than the regional flyway. [ABSTRACT FROM AUTHOR]

Some species of birds react to climate change by reducing the distance they travel during migration. The Odra River Estuary in the Baltic Sea is important for wintering waterfowl and is where we investigated how waterbirds respond to freezing surface waters. The most abundant birds here comprise two ecological groups: bottom-feeders and piscivores. Numbers of all bottom-feeders, but not piscivores, were negatively correlated with the presence of ice. With ongoing global warming, this area is increasing in importance for bottom-feeders and decreasing for piscivores. The maximum range of ice cover in the Baltic Sea has a weak and negative effect on both groups of birds. Five of the seven target species are bottom-feeders (Greater Scaup Aythya marila, Tufted Duck A. fuligula, Common Pochard A. ferina, Common Goldeneye Bucephala clangula and Eurasian Coot Fulica atra), and two are piscivores (Smew Mergellus albellus and Goosander Mergus merganser). Local changes at the level of particular species vary for different reasons. A local decline of the Common Pochard may simply be a consequence of its global decline. Climate change is responsible for some of the local changes in the study area, disproportionately favoring some duck species while being detrimental to others.

The Common Pochard Aythya ferina (Linnaeus, 1758) (Aves: Anseriformes: Anatidae) is recorded for the first time in Vedanthangal Bird Sanctuary, Tamil Nadu, India. As this species is recorded in other parts of Tamil Nadu, a brief sightings and distribution map is also specified.

Quantifying the strength of migratory connectivity or the degree to which breeding and wintering populations are connected is crucial for conservation and management of migratory birds. Using stable hydrogen isotope ratios of secondary flight feathers ( δ H), we assessed the breeding origins/locations of 666 common pochards ( Aythya ferina) and 190 tufted ducks ( A. fuligula) captured in France during the 2005-2006 and 2008-2009 wintering seasons. Isotopic values of common pochards wintering on Grand-lieu Lake (western France) displayed a marked bimodal spatial distribution supportive of strong contributions of both northern (60-65° of latitude) and central European (45-55° of latitude) origins. According to the temporal distribution of δ H values, the presence of common pochards of northern origin reached a maximum at the peak of the wintering season (December-January). In contrast, tufted duck did not display a clear bimodal pattern in δ H, with individuals displaying a more northerly origin (60-70° of latitude), likely of Russian and Scandinavian origin. First-year individuals had more northern origins than adults, suggesting that either isotopic discrimination differed among age groups or, more probably, that some adults may undergo moult at latitudes lower than that of their breeding ground. Tufted ducks with northerly δ H values were observed early in the season in individuals sampled in eastern France and late in the season in those sampled in western France. The effects of winter severity on the distribution of individuals over the wintering range were supported for the tufted duck with more northerly values recorded during harsh winters. Management implications of these results are discussed. [ABSTRACT FROM AUTHOR]

Although the use of lead ammunition for shooting wildfowl and/or over listed wetlands in the UK has been banned, c. 70% of ducks shot in England (the only UK country with compliance monitoring) are still shot with lead and the proportion of ducks found dead with signs of lead poisoning from ingested gunshot has not declined significantly since the ban. However, there is little quantitative evidence of the impacts of additional mortality from lead poisoning on duck populations. For the eight duck species that winter in freshwater habitats in the UK, we found that inter-specific variation in mean population growth rate during the period 1990/1991 to 2013/2014 was significantly negatively correlated with two independent measures of the prevalence of ingested lead gunshot in the UK and Europe. This relationship was found for a wide range of different periods over which population growth was estimated, and also for annual growth rates in the period 1966/1967 to 2013/2014, derived from smoothed population trajectories. These findings support the hypothesis that ingested lead gunshot might affect population trend. An alternative hypothesis, that migratory short-stopping driven by climate change affected trends in numbers of ducks wintering in the UK, was not supported by simple or partial correlation results. The possible impact of ingested lead gunshot on the Common Pochard Aythya ferina, a species listed as globally threatened, is of special concern. [ABSTRACT FROM AUTHOR]

We examined concentrations of cadmium, chromium, iron, lead and zinc in the kidney, liver, and pectoral muscle of Mallards ( Anas platyrhynchos; n = 30) and Pochards ( Aythya ferina; n = 30) from two important wintering sites in the southeastern Caspian Sea in the winter of 2012. Mean lead concentrations (µg g ww) in livers (2.36 ± 1.00) of Pochard and in kidneys (3.43 ± 0.91) of Mallard exceeded the exposure threshold levels in liver (1.5 µg g ww) and kidney (3 µg g ww) of waterfowl. Mean cadmium concentrations in livers (1.63 ± 0.66) of Pochards exceeded the background level of this metal in liver (1 µg g ww) of waterfowl. Chromium, iron and zinc concentrations were within the normal range as reported in other duck studies. Gender-related and inter-specific variation of metal concentrations in analyzed tissues were observed ( t test, p < 0.05). Our results indicated that waterfowl using the Miankalah and Gomishan International Wetlands are being exposed to elevated concentrations of cadmium and lead. [ABSTRACT FROM AUTHOR]

The choice of the moulting habitat is of paramount importance for wing-moulting waterbirds that have to cope with a flightless period of several weeks. However, some species might have more restricted habitat requirements during moult than others, for example due to a highly specialized feeding ecology. The moult-related habitat use of five species (Gadwall Anas strepera, Red-crested Pochard Netta rufina, Common Pochard Aythya ferina, Tufted Duck Aythya fuligula, Coot Fulica atra) was compared at a European inland moulting site that offered a variety of water bodies characterized by different levels of nutrient concentration, water depth, shoreline vegetation density and disturbance. To determine location- and species-specific densities, birds were regularly counted throughout the moulting seasons of 2010 and 2011. In 2011, additional data on Gadwalls were used to assess differences in requirements between the flightless phase of moult and the periods before and after. Furthermore, habitat choice of 38 tagged Gadwalls was compared among two to four successive years. During the moulting season, all species showed clear preferences for specific levels of nutrient content, suggesting an active choice of suitable food sources in both food specialists and generalists. Species showing the strongest attachment to shallow water (Gadwall and Coot) were most sensitive to human disturbance and increasing water depths, and species averse to diving (Gadwall) used ponds with dense shore vegetation while flightless. For Gadwalls, habitat conditions rather than nutrient supply became increasingly important during the flightless phase. Average return rates of 59 and 54% were recorded for male and female Gadwalls, respectively, and the repeated use of familiar locations could be demonstrated in the majority of returning birds (65%). Familiarity with the habitat apparently plays an important role and may enable individuals to compensate for suboptimal conditions at the moulting site. [ABSTRACT FROM AUTHOR]

We examined the diet of the Rosy-billed Pochard, Netta peposaca (Vieillot, 1816), (n = 59) during the autumn of 2010 in Santa Fe province, Argentina. Were analyzed a total of 59 ducks (n = 37 females and n = 22 males) to assess their gastrointestinal contents. The trophic spectrum was composed of 16 taxa (plant fraction: animal fraction 9 and 7). The contribution of each food category estimated using the IRI was: Echynochloa sp. (Poaceae) = 4301, Polygonum sp. (Polygonaceae) = 956, and unidentified graminoid species = 53 (females: Echynochloa sp. = 4313, Polygonum sp. = 1095 and males: Echynochloa sp. = 5522, Polygonum sp. = 814). No significant differences were found between females and males in diet composition (Fisher's test, p < 0.05). Moreover, the diversity index (H') was significantly (Mann-Whitney, p < 0.05) different between sexes. The Rosy-billed Pochard showed a predominantly phytophagous feeding habit in autumn. Likewise, this is the first contribution on the sexual differences in the feeding biology of the Rosy-billed Pochar. [ABSTRACT FROM AUTHOR]

The co-occurrence of functionally similar species is very common in nature, and is often put forward as a basis for ecosystem resilience to disturbance. At the same time, competition between similar species is also considered a strong driver of community composition. However, environmental stochasticity can alter this prediction, either because competitive abilities depend on time-varying factors or because covariance in species' responses to environmental conditions masks the effect of competition. Interactions other than competition can also influence community dynamics but have received less attention. We used a simplified community of two sympatric duck species (redhead Aythya americana and canvasback A. valisineria) and a previously published analysis of 50 years of demographic data to parameterize a stochastic, density-dependent, stage-structured model. These ducks interact via nest parasitism (mostly of canvasback by redhead) in addition to competition for food resources, with consequences at the demographic level; these interactions are modulated by habitat availability (number of ponds in the study landscape). We found that if habitat availability decreased there was a high risk of quasi-extinction, and redheads, although initially able to maintain their numerical dominance, quickly became the least abundant species because they perform worse during droughts. If habitat availability increased, we found that the initially more rare canvasback would increase in relative abundance, albeit slowly. We interpret this as a shift from a community influenced by nest parasitism (which is detrimental to canvasback) to a community mostly driven by species-specific dynamics due to relaxation of resource limitation. [ABSTRACT FROM AUTHOR]

Conspecific brood parasitism (CBP) is a reproductive tactic whereby a parasitic female lays its eggs into the nests of other conspecific females. Genetic-based data on the occurrence of CBP in birds, however, is still relatively scarce. We analysed prevalence of CBP in a ground-nesting diving duck, the common pochard Aythya ferina, using a set of 17 microsatellites. Compared to related species, our population showed a relatively high level of CBP, with 39% of genotyped pochard eggs laid parasitically and 89% of nests containing ≥ 1 parasitic egg. In addition, we observed relatively high rates of interspecific brood parasitism (13% of eggs), caused predominantly by mallard Anas plathyrhynchos and tufted duck Aythya fuligula. CBP eggs had decreased hatching success compared to host eggs, with 65% of CBP and 95% of non-CBP genotyped eggs hatching successfully. Our data suggest that this was probably due to improper timing of parasitic egglaying, which compromised synchronised hatching of CBP and host-eggs. Despite high rates of CBP in our pochard popu lation, fitness costs associated with this reproductive tactic appear to be low for host females since neither clutch size nor host-egg hatching probability were reduced due to CBP. [ABSTRACT FROM AUTHOR]

A total of 3720 samples of 24 waterbird species belonging to 5 orders were collected in Lithuania between 2007 and 2011 for the analysis of avian influenza viruses. One hundred eigthy seven samples were positive for influenza A viruses or antibodies. All influenza A positive samples were found in the mallard (Anas platyrhynchos). The recorded prevalence of influenza A virus in mallards was 7.5%. Among mallards sampled in Lithuania low-pathogenic H7N2, AIVH7 and AIVH5 subtype's viruses prevailed. Other low pathogenic avian influenza subtypes (H1-H4, H6, H8, H9, H10N4 and H12) were also found in mallards, collected in various regions of Lithuania. Therefore in the future active surveillance for avian influenza virus in Lithuania (sampling of apparently healthy wild birds) should give a high priority to the mallard. Following recommendations of the European Commission (EC Directive 2005/94/EC, 2006), certain other species of wildfowl at the higher risk, such as the common pochard (Aythya ferina), tufted duck (Aythya fuligula) and mute swan (Cygnus olor) should be also included into the national monitoring schemes for avian influenza in the countries of the European Union. Passive surveillance (sampling of hunted birds or birds found dead) should pay special attention to the mallard, as well as to the common pochard and tufted duck. Such surveillance scheme should provide an early warning about potential presence of HPATV virus in the country. [ABSTRACT FROM AUTHOR]

This section offers news briefs. Conservationists Wildfoul and Wetlands Trust (WWT), Birds Russia, and the Royal Society for the Protection of Birds (RSPB) will be returning to Chukotka in Russia for its initiative in saving the Spoon-billed Sandpiper Eurynorhynchus pygmeus. The Madagascar Pochard Aythya innotata has successfully bred in captivity in a facility in Antsohihy, Madagascar. The planned culling of 200 Canada Geese Branta canadensis on Windermere in Cumbria has been stopped.

The article presents a case study of a 15-year-old male rosy-billed pochard with multiple endocardial neurofibroma in Boston, Massachusetts. Researchers mentioned that the pochard was found dead inside its enclosure and they did a necropsy on its remains. They found that the bird had enlarged rounded heart and concluded that it died of endocardial neurofibroma.

We assessed the contribution of endogenous fat stores to meeting energetic needs during the flightless moult period in Pochard and Tufted Duck by regressing mass on the progression of wing moult, as measured by primary length. Pochard lost between 22.1% (males) and 24.2% (females) of body mass and female Tufted Duck 12.2% during wing moult at Abberton Reservoir, Essex. Based on a 27-day flightless period, Pochard lost on average 8.3-8.4 g per day and Tufted Duck 3.2-3.4 g per day, presumably due to fat expenditure. Assuming the daily energy expenditure (DEE) to be 1.7× the basal metabolic rate (BMR), the contribution from burning endogenous fat equated to 37-40% of Pochard and 19-20% of Tufted Duck DEE during remiges moult. One frequently re-trapped female Pochard expended fat stores that almost fulfilled her entire energetic requirements during moult if she rested and did not feed for most of the moult. These results confirm that Pochard and Tufted Duck accumulate fat stores that help to meet energetic needs during the flightless wing moult period. This endogenous source of energy may free them to exploit habitats that are safe from predation but which may not fully supply the energetic needs of moulting ducks from exogenous sources. [ABSTRACT FROM AUTHOR]

The Mute Swan ( Cygnus olor) is a protected species whose population has shown a dramatic demographic expansion over the last decades in France. Today, Mute Swans are suspected of causing damages to wetlands, partly through their territorial behaviour towards other waterbirds. The behaviour of Mute Swan pairs and the distribution of other waterbirds was monitored over 84 fishponds in the Dombes, Eastern France, from April to July 2008. Interspecific aggressive behaviours by Mute Swan pairs were not detected during behavioural observations, and no negative impact of swan pair presence was demonstrated on waterbird distribution. Waterbirds were more abundant on fishponds where Mute Swan pairs were present, maybe due to the flocking of waterbirds where Mute Swans were established owing to shared habitat preferences. Indeed, the waterbirds whose presence was the most closely correlated to that of Mute Swan pairs were Coot ( Fulica atra), Common Pochard ( Aythya ferina) and Red-Crested Pochard ( Netta rufina), all foraging on deep macrophyte beds as do the swans. All these species, including swans, may therefore be attracted to the same fishponds without massive interspecific competition occurring, due to abundant submerged aquatic vegetation resources. [ABSTRACT FROM AUTHOR]

Copyright of Hydroécologie Appliquée is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Waterbirds represent the major natural reservoir for low pathogenic (LP) avian influenza viruses (AIV). Among the wide diversity of subtypes that have been described, two of them (H5 and H7) may become highly pathogenic (HP) after their introduction into domestic bird populations and cause severe outbreaks, as is the case for HP H5N1 in South-Eastern Asia. Recent experimental studies demonstrated that HP H5N1 AIV infection in ducks does not necessarily have significant pathological effects. These results suggest that wild migratory ducks may asymptomatically carry HP AIV and potentially spread viruses over large geographical distances. In this study, we investigated the potential spreading distance of HP AIV by common teal ( Anas crecca), mallard ( A. platyrhynchos), and Eurasian pochard ( Aythya ferina). Based on capture-mark-recapture method, we characterized their wintering movements from a western Mediterranean wetland (Camargue, South of France) and identified the potential distance and direction of virus dispersal. Such data may be crucial in determining higher-risk areas in the case of HP AIV infection detection in this major wintering quarter, and may serve as a valuable reference for virus outbreaks elsewhere. [ABSTRACT FROM AUTHOR]

The article focuses on a study which describes experimentally the reactions of incubating common female pochards towards an egg lying beside their nests. The study was conducted using time-lapse video recorders. Results of the study show that the female pochard does not discriminate between conspecific and heterospecific eggs when retrieving them. The researchers speculate that the retrieval of unrelated eggs can be a result of an imperfect recognition ability of the female, anti-predation defense or brood parasitism tendencies.

Abstract: Trade-off between offspring size and number belongs to the most discussed concepts in the life history theory. Although it has been frequently described at interspecific level as a negative correlation between egg size and number, it is usually difficult to provide similar evidence at a population level. In congruence with most of previous studies, we did not find any evidence for negative correlation between estimated egg mass and clutch size in the Common Pochard (Aythya ferina). However, the predicted negative relationship appeared after incubation when young with many siblings were on average lighter than conspecifics in nests with fewer young. Such a pattern might be generated by differences in hatching success and energy consumption by developing embryos among particular nests. Our data indicate that females which had laid clutches containing many big eggs lost a much larger amount of energy invested and, moreover, produced hatchlings of relatively lower body mass if compared with females having few small eggs. We speculate about variation in energy allocation between two most energy demanding parts of breeding (clutch formation and incubation) and female incubation effort as leading mechanisms. Such a variation might reflect inter-individual differences in reproductive strategy or errors in energy allocation. [Copyright &y& Elsevier]

Highly pathogenic avian influenza (HPAI) viruses of subtype H5N1 have spread since late 2003 in East and Southeast Asia. In April 2005, a large-scale outbreak of H5N1 infection that occurred in migratory waterfowl in Qinghai Lake nature reserve in western China, killing more than 6000 wild birds, appeared to be the beginning of a epizootic that caused outbreaks in domestic and wild birds in nearly 60 countries from Central Asia, the Middle East, Europe and Africa. The first case of Asian lineage HPAI H5N1 virus in France was described in dead wild ducks (Common pochard) in the east of France in mid-February 2006. Up to the end of April, 42 HPAI H5N1 viruses were identified from about 60 wild birds belonging to different species and one outbreak occurred in commercial turkeys. To establish genetic relationships with other HPAI H5N1 viruses, 12 selected viruses were subjected to phylogenetic analysis. Genotyping and genetic analyses revealed that the French viruses were very similar to those of the 'Qinghai-like' sublineage and belonged to clade 2.2. However, two related but distinct genetic subgroups were identified, indicating that two different viruses were circulating in France at the same time and in the same area. Viruses of one subgroup were highly similar to one identified in Bavaria in Germany (A/mallard/Bavaria/1/2006). More surprisingly, French viruses belonging to the other subgroup retained the cleavage motif PQGERKRKKR/G, which is unique among the known HPAI H5N1 viruses. Our results confirmed that multiple H5N1 genogroups were present in Western Europe in early 2006. [ABSTRACT FROM AUTHOR]

Abstract: Bones and cartilage of two species of diving ducks: the scaup Aythya marila (n =24) and the pochard A. ferina (n =24) were studied. Scaup is protected in Poland where it spends only the winter, while pochard is a game bird, abundant and breeding in Poland. In winter, the two species form large flocks off the southern coast of the Baltic, particularly in the Szczecin Lagoon where they were collected for this study. The bones and cartilage (trachea) were assayed for concentrations (dry weight-based) of three essential metals: iron (Fe), copper (Cu), and zinc (Zn); concentrations of the two toxic metals: lead (Pb) and cadmium (Cd) were assayed as well. These hard tissues of the two species showed the following order of metal concentrations Zn>Fe>Pb>Cu>Cd. In scaup and pochard bones, the respective geometric mean concentrations of Zn, Fe, Pb, Cu, and Cd were 94.4 and 102.0; 20.2 and 24.7; 6.2 and 9.6; 0.19 and 0.26; 0.114 and 0.162 mg/kg. The levels of all the metals in cartilage (Zn 149.1 and 165.8; Fe 58.4 and 116.3; Pb 10.6 and 14.9; Cu 1.41 and 3.31; Cd 0.144 and 0.175 mg/kg, respectively) were higher than in the bones of A. marila and A. ferina. However, statistically significant differences were found in respect to the essential metals only (Zn, Fe, Cu). The inter-species comparisons showed the two species to differ in their cartilage concentrations of Fe, Cu, Zn, and Cd and in their bone concentrations of Pb and Cd. In each case, the pochard exhibited higher concentrations of metals. This study showed distinct differences between trace element accumulation by two heavily mineralised avian body parts: leg bones (tarsometatarsus) and cartilage (trachea). The results are in agreement with data reported by other workers who analysed trace metals in cartilaginous and bone components of the femoral head in homoiotherm vertebrates, including humans. Therefore it is important that intra- and inter-species comparisons of hard biological components be based on corresponding body parts, and that relevant biochemical and ecotoxicological research be pursued. [Copyright &y& Elsevier]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Waterfowl management on breeding grounds focuses on improving nest success, but few studies have compared waterfowl nest success and factors affecting nest survival along a wetland gradient and simultaneously identified nest predators. We monitored nests (n = 195) of common pochards (Aythya ferina) in Trebon Basin Biosphere Reserve, Czech Republic, during 1999-2002. Daily nest survival rates (DSRs, logistic-exposure) declined from island (0.985, 95% confidence interval, 0.978-0.991) to overwater (0.962, 0.950-0.971) and terrestrial (0.844, 0. 759-0.904) nests. The most parsimonious model for DSRs included habitat class (DSRs: island > overwater > terrestrial) and nest visibility. Nest survival was improved by reduced nest visibility, increased water depth, and increased distance from the nest to habitat edge in littoral habitats. On islands, nest success increased with advancing date and increased distance to open water. A model of constant nest survival best explained the data for terrestrial nests. There were no observer effects on DSRs in any habitat. In 2003, artificial nests (n = 180; 120 contained a wax-filled egg) were deployed on study plots. The model that best explained variation in DSRs for artificial nests included only 1 variable: habitat class (DSRs: island ≥ overwater > terrestrial). Mammalian predation of artificial nests (by foxes [Vulpes vulpes] and martens [Martes spp.]) was more likely in terrestrial habitats than in littoral habitats or on islands. By contrast, corvids and marsh harriers (Circus aeruginosus) prevailed among predators of overwater and island nests. Our data indicate that artificial islands and wide strips of littoral vegetation may represent secure breeding habitats for waterfowl because those habitats allow nests to be placed in areas that are not accessible to, or that are avoided by, mammalian predators. Management actions should be aimed at preserving these habitats. This, along with creation of new artificial islands, could help to enhance breeding productivity of pochards and possibly other waterfowl species inhabiting man-made ponds. [ABSTRACT FROM AUTHOR]

Western European populations of red-crested pochard ( Netta rufina) are characterized by low size and high fragmentation, which accentuate their sensitivity to hunting. Uncertainties regarding the demographic trends of these populations highlight the need for pertinent hunting regulations. This requires identification of the limits of the populations under exploitation, i.e. delimiting a management unit. We used the left domain of the mitochondrial control region and seven nuclear loci (four microsatellites and three introns) to assess the level of genetic structure and demographic independence between the fragmented Western European and the large Central Asian populations. The second objective was to investigate the colonization history of the Western European populations. This study demonstrated that the Western European populations of red-crested pochard constitute a separate demographic conservation unit relative to the Asian population as a result of very low female dispersal (mitochondrial DNA: ΦST = 0.152). A morphometric analysis further suggested that Central Asian and Western European specimens of both sexes originate from different pools of individuals. Male dispersal seems higher than female dispersal, as suggested by the lack of clear genetic structure for the nuclear markers at this continental scale. Genetic data, in conjunction with historical demographic data, indicate that the current Western European populations probably originate from a recent colonization from Central Asia. As numbers of red-crested pochards in Western Europe cannot be efficiently supplemented by immigration from the larger Asian populations, a management plan regulating the harvest in Western Europe is required. [ABSTRACT FROM AUTHOR]

The red-crested pochard (Netta rufina), a Eurasian diving duck, has seen its numbers declining and has received strong conservation concern. Data on population size and rate of decline are required to establish management plans, none of which is available for this species. Here we present the first population size estimate taking into account detection probability and habitat use in the Camargue, southern France. A non-random sample of 33 lakes was used to estimate detection probability from point-counts. Detectability was low, with only 57.5% of individual broods detected. A random sample of 37 lakes was then used to estimate brood densities. Adjusted densities (taking into account detection probability) were 0.1106 broods per ha of reedbed. Adjusted densities were extrapolated to the entire surface area of reedbeds in the Camargue estimated from a GIS to obtain abundance estimates of the brood population. A minimum estimate of 559 breeding pairs was obtained (95% confidence interval: 436-855). This estimate is much higher than previous ones (80-100 pairs for the Camargue, 250 pairs for France), and indicates strong underestimation of the population size when not taking into account detectability. Our results suggest that the red-crested pochard may require a reassessment of its conservation status for France and Europe. They further suggest that taking detection probability into account in population estimates of other cryptic species, and notably those of conservation concern, may help clarify their conservation status and may even affect the setting of conservation priorities. [ABSTRACT FROM AUTHOR]

Presents information on a study which compared reproductive success and adult survival between nonparasitized and parasitized female Tufted Ducks and Common Pochards. Field procedures conducted; Prehatch costs of brood parasitism to host females; Potential posthatch costs of brood parasitism.

One of the UK's largest flocks of pochard Aythya ferina and tufted duck A. fuligula winters in Manchester's busy dockland redevelopment area. I examined the effects of human disturbance on the population, and used this information to recommend minimal land-use restrictions that will help ensure the population's continued use of the site. Birds fed at the docks every night, but on 75% of days, the flock flew to suburban or rural refuges in response to disturbance. The common causes of disturbance, particularly pedestrians, did not affect the duck greatly, but disturbances associated with building and redevelopment of the site (e.g., machinery) often made duck evacuate the dock. While birds were no less likely to evacuate the docks as the winter progressed, they did show some short-term flexibility in their responses to disturbance. For example, birds appeared able to sit out disturbances throughout the afternoon if they had avoided evacuation of the docks during the morning. Birds spent only a small proportion of time feeding, and feeding activity was not heightened following periods of exclusion from the docks due to disturbance. Daytime feeding activity was elevated during periods of lowering temperatures, and despite heavy disturbance at the site, the impact of disturbance may only be significant during the coldest period of the winter. During very cold spells, it is important to limit the incidence of unusual disturbances, such as evening concerts and waterborne activities which tend to make duck evacuate the site. [ABSTRACT FROM AUTHOR]

Highlights formal studies of senescence hypotheses in animal survival, focusing on the Common Pochards `Aythya ferina.' Information on the studies; Limit to the test relating to survival probabilities; Details on the conclusion.

Tests models previously developed by the authors to predict the allocation of time over dive cycle for aerobic divers that maximize gross and net rates of energy intake under a range of conditions, using the pochard bird. Costs and benefits of foraging; Qualitative tests of predictions; Birds' ability to assess options differing in waterdepth and food concentration.

The article reports on the first occurrence of common pochard Aythya ferina at the Vedanthangal Bird Sanctuary in Tamil Nadu, India on January 10, 2009. It states that the global population of common pochard ranges from 22,00,000-25,000,000. It notes that common pochard prefers open water area and reservoirs with submerged vegetation, and suggests further monitoring and surveillance in and around the sanctuary during winter to determine whether its occurrence was accidental or is regular.

The article presents information on the recent developments in environmental research. A survey team found several Madagascar pochards, a critically endangered diving duck in a lake in northern Madagascar. A new species of sucker-footed bat has been discovered in the forest of Madagascar. A study on flamingo at lake Bogoria in Kenya showed that the malnutrition may be one of the factors responsible for their increasing death, which has been caused by heavy rainfall.