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Miller, Michael R., and John McA. Eadie. "The Allometric Relationship between Resting Metabolic Rate and Body Mass in Wild Waterfowl (Anatidae) and an Application to Estimation of Winter Habitat Requirements." Condor 108, no. 1 (February 1, 2006): 166–77. http://dx.doi.org/10.1093/condor/108.1.166.
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AbstractWe examined the allometric relationship between resting metabolic rate (RMR; kJ day−1) and body mass (kg) in wild waterfowl (Anatidae) by regressing RMR on body mass using species means from data obtained from published literature (18 sources, 54 measurements, 24 species; all data from captive birds). There was no significant difference among measurements from the rest (night; n = 37), active (day; n = 14), and unspecified (n = 3) phases of the daily cycle (P > 0.10), and we pooled these measurements for analysis. The resulting power function (aMassb) for all waterfowl (swans, geese, and ducks) had an exponent (b; slope of the regression) of 0.74, indistinguishable from that determined with commonly used general equations for nonpasserine birds (0.72–0.73). In contrast, the mass proportionality coefficient (b; y-intercept at mass = 1 kg) of 422 exceeded that obtained from the nonpasserine equations by 29%–37%. Analyses using independent contrasts correcting for phylogeny did not substantially alter the equation. Our results suggest the waterfowl equation provides a more appropriate estimate of RMR for bioenergetics analyses of waterfowl than do the general nonpasserine equations. When adjusted with a multiple to account for energy costs of free living, the waterfowl equation better estimates daily energy expenditure. Using this equation, we estimated that the extent of wetland habitat required to support wintering waterfowl populations could be 37%–50% higher than previously predicted using general nonpasserine equations.
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Sruoga, Aniolas, Sigita Slavėnaitė, Dalius Butkauskas, and Gediminas Gražulevičius. "Cross-Species Applicability of Microsatellite Markers for Investigation of Sea Ducks (Mergini) Genetic Differentiation." Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 62, no. 6 (January 1, 2008): 215–18. http://dx.doi.org/10.2478/v10046-009-0002-0.
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Cross-Species Applicability of Microsatellite Markers for Investigation of Sea Ducks (Mergini) Genetic Differentiation Genetic studies of waterfowl have provided insufficient information on the evolutionary history of the sea duck tribe (Mergini, Anseriformes), as highly variable molecular markers have not been identified. Cross-species applicability of microsatellites has been shown for several bird families. Therefore, the objective of our work was to examine whether specific primers used previously for Anatidae, Phasianidae and Laridae taxons could amplify microsatellite loci of sea duck species: Long-tailed duck (Clangula hyemalis), Goosander (Mergus merganser) and Velvet Scoter (Melanitta fusca). Tissue samples were collected and DNA was extracted by rapid salt extraction method. Amplification of DNA fragments was carried out using specific microsatellite primers of APH21, Aalmu1, Sfimu4, Sfimu5 (Anatidae), ADL209, ADL115 (Phasianidae) and K71, RGB28 (Laridae). Four primer pairs (APH21, Aalmu1, K71, and nSfimu4) were suitable for investigation of interspecies genetic variability among Long-tailed duck and Velvet Scoter. Intraspecies specificity has been detected for primer pair ADL 209 in all three duck species. The primer pair APH21 was selected as most promising for investigation of intraspecies variability of Long-tailed duck and Velvet Scoter.
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Knee, Wayne, and Terry D. Galloway. "Myialges trinotoni (Acariformes: Epidermoptidae), a hyperparasitic mite infesting Trinoton querquedulae (Phthiraptera: Menoponidae) on waterfowl." Canadian Entomologist 149, no. 4 (May 8, 2017): 434–43. http://dx.doi.org/10.4039/tce.2017.16.
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AbstractMites of the family Epidermoptidae (Acariformes) are permanent parasites dwelling on or in the skin of birds. Myialges Trouessart species are epidermoptids that have a hyperparasitic relationship with chewing lice (Phthiraptera) or louse flies (Diptera: Hippoboscidae). During 1993–2016 in Manitoba, Canada, 668 ducks (20 species), geese (five species), and swans (two species) were examined for lice. A total of 157 males, 191 females, and 539 nymphs of the menoponid louse Trinoton querquedulae (Linnaeus) (Phthiraptera: Menoponidae) were collected, of which 25 adult lice from three hosts (Mergus merganser Linnaeus, Lophodytes cucullatus (Linnaeus), Anas platyrhynchos Linnaeus; Aves: Anatidae) were infested with 38 female Myialges trinotoni (Cooreman). Overall prevalence and intensity of M. trinotoni was low, and mites showed no statistically significant preference between male and female lice. Myialges trinotoni is recorded from Canada (Manitoba) and United States of America (Alaska) for the first time, and two novel avian host species records (Lophodytes cucullatus and Anas platyrhynchos) are reported. The male of M. trinotoni (loose in bird washing) is illustrated and described. The barcode region of cytochrome oxidase subunit I (COI) was amplified from M. trinoton and compared with that of Myialges caulotoon Speiser, the only congeneric species for which COI is available, and interspecific divergence was high (25%).
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De Pietri, Vanesa L., R. Paul Scofield, Nikita Zelenkov, Walter E. Boles, and Trevor H. Worthy. "The unexpected survival of an ancient lineage of anseriform birds into the Neogene of Australia: the youngest record of Presbyornithidae." Royal Society Open Science 3, no. 2 (February 2016): 150635. http://dx.doi.org/10.1098/rsos.150635.
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Presbyornithids were the dominant birds in Palaeogene lacustrine assemblages, especially in the Northern Hemisphere, but are thought to have disappeared worldwide by the mid-Eocene. Now classified within Anseriformes (screamers, ducks, swans and geese), their relationships have long been obscured by their strange wader-like skeletal morphology. Reassessment of the late Oligocene South Australian material attributed to Wilaru tedfordi , long considered to be of a stone-curlew (Burhinidae, Charadriiformes), reveals that this taxon represents the first record of a presbyornithid in Australia. We also describe the larger Wilaru prideauxi sp. nov. from the early Miocene of South Australia, showing that presbyornithids survived in Australia at least until ca 22 Ma. Unlike on other continents, where presbyornithids were replaced by aquatic crown-group anatids (ducks, swans and geese), species of Wilaru lived alongside these waterfowl in Australia. The morphology of the tarsometatarsus of these species indicates that, contrary to other presbyornithids, they were predominantly terrestrial birds, which probably contributed to their long-term survival in Australia. The morphological similarity between species of Wilaru and the Eocene South American presbyornithid Telmabates antiquus supports our hypothesis of a Gondwanan radiation during the evolutionary history of the Presbyornithidae. Teviornis gobiensis from the Late Cretaceous of Mongolia is here also reassessed and confirmed as a presbyornithid. These findings underscore the temporal continuance of Australia’s vertebrates and provide a new context in which the phylogeny and evolutionary history of presbyornithids can be examined.
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Dawson, Terence J., Peter J. Whitehead, Adam McLean, F. D. Fanning, and William R. Dawson. "Digestive function in Australian magpie geese (Anseranas semipalmata)." Australian Journal of Zoology 48, no. 3 (2000): 265. http://dx.doi.org/10.1071/zo00011.
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The Australian magpie goose (Anseranas semipalmata) is not really a ‘goose’ but an aberrant species representing the monotypic family Anseranatidae. It is herbivorous but its ability to utilise dietary fibre is uncertain. We examined digestive processes in tame birds fed natural forages in metabolism cages and in wild birds. An examination of the gross anatomy of the gut showed features similar to those in waterfowl of the family Anatidae, the true ducks and geese. In a total-collection feeding trial geese were fed either unhusked rice grain or fresh aquatic grass. The aquatic grass was high in fibre (neutral detergent fibre (NDF) was 74% of dry matter) and magpie geese could not maintain energy or nitrogen balance on this feed. The maintenance energy requirement of the caged magpie geese, as estimated on the rice diet, was 573 kJ kg–1 day–1, which was similar to that found for other species of geese. The maintenance nitrogen requirement was 0.44 g N kg–1 day–1 or 0.52 g N kg–0.75 day–1, which also was similar to the average value for birds. Fibre digestion on both diets was small, 19% and 27% of NDF for rice and grass respectively. Rates of passage of fibrous digesta through the gut of magpie geese varied with diet. The mean retention time for fibre was longer when feeding on the aquatic grass than on unhusked grain, 7.7 3.0 h v. 3.7 0.6 h Data from wild magpie geese clarified the process of digestion. The patterns of pH and short-chain fatty acids along the gut pointed to acid and enzymic digestion occurring in most of the tract, down to the ileocaecal junction. Fermentation appeared restricted to the caeca, rectum and cloaca, though, of note, the caeca contained little fibre, 5% NDF. Higher levels of fibre digestion were indicated in wild geese but fibre still was not a major contributor to the energy intake of these birds. The digestive capabilities of the magpie geese were considered in relation to their impact on the feeding and reproductive biology of these ‘geese’ in monsoonal, northern Australia
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Tubelyte, Vaida, Saulius Švažas, Aniolas Sruoga, Dalius Butkauskas, Algimantas Paulauskas, Vykintas Baublys, Janis Viksne, Gennady Grishanov, and Alexander Kozulin. "Genetic diversity of tufted ducks (Aythya fuligula, Anatidae) in Eastern Europe." Open Life Sciences 6, no. 6 (December 1, 2011): 1044–53. http://dx.doi.org/10.2478/s11535-011-0083-z.
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AbstractThe tufted duck (Aythya fuligula, Anatidae) is widespread in the Palaearctic across Northern Eurasia. Birds breeding in Northern and Eastern Europe are highly migratory, while populations from Western Europe are partially migratory or resident. The aim of this study is to explore genetic variation within and between ducks breeding in Latvia and migrants sampled in North West Russia and Belarus. The technique of random amplified polymorphic DNA was applied using five random primers (ol-1, ol-9-12). Genetic variability was measured for all tufted ducks investigated and for different sub-populations from various regions. Individual genetic structure and genetic variability was higher in ducks collected from Latvia. Gene diversity of amplified DNA bands in birds of Latvian origin was 24% with 80% polymorphism. Means of gene diversity and polymorphism for tufted ducks sampled in other countries varied from 12 to 14% and from 27 to 40%, respectively. A high number of unique bands characterized ducks breeding in Latvia. The oligonucleotide primers used in this study were suitable to analyze differences among tufted ducks of different origin. Possible explanations for the variation observed among the studied ducks are discussed.
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Payne, Susan L., Pauline Delnatte, Jianhua Guo, J. Jill Heatley, Ian Tizard, and Dale A. Smith. "Birds and bornaviruses." Animal Health Research Reviews 13, no. 2 (December 2012): 145–56. http://dx.doi.org/10.1017/s1466252312000205.
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AbstractIn 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first identified in the late 1970s. ABV infection has subsequently been shown to be widespread in wild waterfowl across the United States and Canada where the virus infects 10–20% of some populations of ducks, geese and swans. In most cases birds appear to be healthy and unaffected by the presence of the virus; however, infection can also result in severe non-suppurative encephalitis and lesions similar to those seen in parrots with PDD. ABVs are genetically diverse with seven identified genotypes in parrots and one in canaries. A unique goose genotype (ABV-CG) predominates in waterfowl in Canada and the northern United States. ABV appears to be endemic in North American waterfowl, in comparison to what appears to be an emerging disease in parrots. It is not known whether ABV can spread between waterfowl and parrots. The discovery of ABV infection in North American waterfowl suggests that European waterfowl should be evaluated for the presence of ABV, and also as a possible reservoir species for Borna disease virus (BDV), a related neurotropic virus affecting horses and sheep in central Europe. Although investigations have suggested that BDV is likely derived from a wildlife reservoir, for which the shrew and water vole are currently prime candidates, we suggest that the existence of other mammalian and avian reservoirs should not be discounted.
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Yu, Rujin. "Relationship Between Water Birds’ Number and the Temperature in Beijing Wetland: A Case Study on Cuihu Wetland." E3S Web of Conferences 245 (2021): 02032. http://dx.doi.org/10.1051/e3sconf/202124502032.
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Beijing is an important transfer station of bird migration, and its function as a bird habitat is very significant. Wetland birds have an extremely high reference value as ecological indicators and are greatly affected by climate change. This study takes waterbirds in Beijing Cuihu Wetland Park as the research object, carries out a statistical analysis of the number of birds in each year, and summarizes the relationship between them and Beijing's climate change. The results showed that Anatidae and Ardeidae accounted for a substantial part of wetland waterfowl, and their number was increasing year by year. There was a significant correlation between the monthly average number of two kinds of waterfowls and the average monthly temperature, and the negative correlation was found between the number of Anatidae and the average monthly temperature. The number of Anatidae and Ardeidae in spring and autumn are related to the monthly average temperature, seasonal average temperature and annual average temperature of the previous year.
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Patton, J. C., and J. C. Avise. "Evolutionary genetics of birds IV rates of protein divergence in waterfowl (Anatidae)." Genetica 68, no. 2 (January 1986): 129–43. http://dx.doi.org/10.1007/bf02424410.
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Sturm-Ramirez, K. M., D. J. Hulse-Post, E. A. Govorkova, J. Humberd, P. Seiler, P. Puthavathana, C. Buranathai, et al. "Are Ducks Contributing to the Endemicity of Highly Pathogenic H5N1 Influenza Virus in Asia?" Journal of Virology 79, no. 17 (September 1, 2005): 11269–79. http://dx.doi.org/10.1128/jvi.79.17.11269-11279.2005.
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ABSTRACT Wild waterfowl are the natural reservoir of all influenza A viruses, and these viruses are usually nonpathogenic in these birds. However, since late 2002, H5N1 outbreaks in Asia have resulted in mortality among waterfowl in recreational parks, domestic flocks, and wild migratory birds. The evolutionary stasis between influenza virus and its natural host may have been disrupted, prompting us to ask whether waterfowl are resistant to H5N1 influenza virus disease and whether they can still act as a reservoir for these viruses. To better understand the biology of H5N1 viruses in ducks and attempt to answer this question, we inoculated juvenile mallards with 23 different H5N1 influenza viruses isolated in Asia between 2003 and 2004. All virus isolates replicated efficiently in inoculated ducks, and 22 were transmitted to susceptible contacts. Viruses replicated to higher levels in the trachea than in the cloaca of both inoculated and contact birds, suggesting that the digestive tract is not the main site of H5N1 influenza virus replication in ducks and that the fecal-oral route may no longer be the main transmission path. The virus isolates' pathogenicities varied from completely nonpathogenic to highly lethal and were positively correlated with tracheal virus titers. Nevertheless, the eight virus isolates that were nonpathogenic in ducks replicated and transmitted efficiently to naïve contacts, suggesting that highly pathogenic H5N1 viruses causing minimal signs of disease in ducks can propagate silently and efficiently among domestic and wild ducks in Asia and that they represent a serious threat to human and veterinary public health.
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Sato, Fumiyuki, Satoshi Tanaka, Shinji Kirihara, and Yoshiyuki Tanaka. "The influence of migratory birds on the distribution of the seagrass Zostera japonica." Botanica Marina 63, no. 6 (December 16, 2020): 521–25. http://dx.doi.org/10.1515/bot-2020-0045.
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AbstractGrazing pressure by animals can change the distribution and biomass of seagrass. We examined grazing pressure by conducting transect surveys and acquiring aerial images by drone before and after the arrival of migratory birds along the Asadokoro tide flats, Aomori Prefecture, Japan. The distribution and biomass of the seagrass Zostera japonica decreased sharply between October and November 2018, which was when migrating waterfowl arrived. We hypothesized that grazing pressure by migrating birds such as the Anatidae, including whooper swans (Cygnus cygnus) and brent geese (Branta bernicla), had a major effect on the decline in Z. japonica in late October. Shortly after the Anatidae arrived, most of the Z. japonica in the shallows disappeared, including the belowground parts. The abundance of Z. japonica in this area was insufficient to support wintering swans. Swans likely need food other than Z. japonica for overwintering.
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Pecsics, Tibor, Miklós Laczi, Gergely Nagy, and Tibor Csörgő. "The cranial morphometrics of the wildfowl (Anatidae)." Ornis Hungarica 25, no. 1 (June 27, 2017): 44–57. http://dx.doi.org/10.1515/orhu-2017-0004.
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Abstract Wildfowl (Anatidae) are a diverse group of birds and globally distributed. These birds feed by widely varying methods, there are generalist and specialist species. In a number of vertebrate taxa trophic specializations have led to distinct differences in the morphology of the skull, like in birds. Our knowledge and understanding of the relationship between cranial morphology and feeding mechanism of wildfowl are limited. The aim of this article is to increase our knowledge of the relationship between skull shape and foraging habits and find the identifiable attributes of the differently adapted groups. We used morphometric methods with 7 linear measurements of the skull. We used principal component (PC) analysis to identify the groups with different foraging habits. The PCs were related to measurements which represent the demanded muscle mass for feeding and the amount of capable food items. The grazers have a narrower bill and bigger bone surface which requires more muscle tissue than the broad billed filter-feeders. We observed the structural and functional differences between grazers and filter-feeders. There are no important differences in the bill measurements between omnivore dabbling and diving ducks. Only the bill is not enough to deduce the foraging habits.
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Callicutt, James T., Heath M. Hagy, and Michael L. Schummer. "The Food Preference Paradigm: A Review of Autumn–Winter Food Use by North American Dabbling Ducks (1900–2009)." Journal of Fish and Wildlife Management 2, no. 1 (June 1, 2011): 29–40. http://dx.doi.org/10.3996/102010-jfwm-038.
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Abstract Studies describing food use (i.e., diet) of nonbreeding dabbling ducks Anas spp. are essential to understanding physiological needs of and recommending habitat management for these birds. We conducted a review of published autumn and winter food-use studies of dabbling ducks in North America to characterize the current state of knowledge and identify remaining research needs. We initiated our review to determine whether valuations of duck foods and the term “preference” commonly used by researchers and in waterfowl management guides (i.e., the food preference paradigm) were supported by available peer-reviewed literature. We analyzed peer-reviewed literature (1900–2009) on autumn–winter food use of dabbling ducks (n = 59 studies). Most studies (68%) used methods known to contain substantial bias including data from gizzards and hunter-collected ducks. Only 5% of published articles reliably determined food selection by concurrently measuring food use and availability, and no study determined food use at a scale appropriate for winter home ranges of dabbling ducks. In some habitats commonly managed for waterfowl (e.g., agricultural lands), few if any collections of ducks are available to obtain data on food use. The limited geographic and habitat scope of unbiased food use and selection studies for dabbling ducks during autumn and winter suggests that the food-preference paradigm found in waterfowl management literature is not supported by empirical evidence and that managers must continue to use best judgment in managing foraging habitats for waterfowl. Researchers and conservation planners should aim to reduce uncertainty regarding the value of waterfowl foods by conducting contemporary food-selection studies using unbiased collection and processing methodologies. Further, we suggest future researchers conduct concurrent behavioral observations, habitat use, and food selection studies within winter home ranges of dabbling ducks to aid managers in meeting the nutritional requirements of dabbling ducks during autumn and winter in North America.
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Sturm-Ramirez, Katharine M., Trevor Ellis, Barry Bousfield, Lucy Bissett, Kitman Dyrting, Jerold E. Rehg, Leo Poon, Yi Guan, Malik Peiris, and Robert G. Webster. "Reemerging H5N1 Influenza Viruses in Hong Kong in 2002 Are Highly Pathogenic to Ducks." Journal of Virology 78, no. 9 (May 1, 2004): 4892–901. http://dx.doi.org/10.1128/jvi.78.9.4892-4901.2004.
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ABSTRACT Waterfowl are the natural reservoir of all influenza A viruses, which are usually nonpathogenic in wild aquatic birds. However, in late 2002, outbreaks of highly pathogenic H5N1 influenza virus caused deaths among wild migratory birds and resident waterfowl, including ducks, in two Hong Kong parks. In February 2003, an avian H5N1 virus closely related to one of these viruses was isolated from two humans with acute respiratory distress, one of whom died. Antigenic analysis of the new avian isolates showed a reactivity pattern different from that of H5N1 viruses isolated in 1997 and 2001. This finding suggests that significant antigenic variation has recently occurred among H5N1 viruses. We inoculated mallards with antigenically different H5N1 influenza viruses isolated between 1997 and 2003. The new 2002 avian isolates caused systemic infection in the ducks, with high virus titers and pathology in multiple organs, particularly the brain. Ducks developed acute disease, including severe neurological dysfunction and death. Virus was also isolated at high titers from the birds' drinking water and from contact birds, demonstrating efficient transmission. In contrast, H5N1 isolates from 1997 and 2001 were not consistently transmitted efficiently among ducks and did not cause significant disease. Despite a high level of genomic homology, the human isolate showed striking biological differences from its avian homologue in a duck model. This is the first reported case of lethal influenza virus infection in wild aquatic birds since 1961.
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Stephenson, Richard. "The contributions of body tissues, respiratory system, and plumage to buoyancy in waterfowl." Canadian Journal of Zoology 71, no. 8 (August 1, 1993): 1521–29. http://dx.doi.org/10.1139/z93-215.
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This study examines buoyancy partitioning between body compartments in diving and surface-feeding Anatidae. Body tissue and plumage densities and the volumes of air in the respiratory system and plumage were analyzed using cadavers and restrained live specimens of waterfowl. The densities of the skeleton and remiges of surface feeders were significantly lower than those of divers but the differences were not sufficient to significantly reduce the body tissue density and buoyant force of divers. There were no other statistically significant differences in the body tissue densities of diving and surface-feeding waterfowl. The densities of contour feathers, down, and remiges were markedly different from each other but the net buoyant force of the feathers was less than 5% of that caused by the air trapped in the plumage layer. All cadavers were negatively buoyant in the absence of air in the respiratory system and plumage. Despite similar net buoyant forces, there were large differences in the volumes of air in the respiratory system and plumage between restrained ducks and cadavers. These results indicate that the use of cadavers or restrained ducks to determine net buoyancy, and hence power output, during voluntary foraging behaviour is unreliable.
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Metz, Karen J., and C. Davison Ankney. "Are brightly coloured male ducks selectively shot by duck hunters?" Canadian Journal of Zoology 69, no. 2 (February 1, 1991): 279–82. http://dx.doi.org/10.1139/z91-043.
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In many species of ducks, males are harvested at higher rates than females. Several studies have suggested that particular aspects of the birds' biology may account for this difference, but few studies have attempted to determine the effect of hunter behaviour on the differential vulnerability. The objective of this study was to determine if the bright plumage of male ducks was related to greater hunting mortality. Ducks shot from pairs at Long Point Waterfowl Management Unit, Ontario, from September 25 to November 26, 1987, were examined, and questions were asked of hunters who brought the ducks into the Waterfowl Management Unit's check station. Sixty-one percent of ducks shot from pairs were mallards, green-winged teal, or ring-necked ducks. A significant interaction occurred between the degree of dichromatism of plumage and which sex of duck was shot. Approximately equal numbers of males and females were shot when males resembled females. However, when males obtained their full, bright, alternate plumage, a significantly greater proportion of males were shot regardless of which sex was leading. These data suggest that hunters select, consciously or unconsciously, the more distinctive male when he is accompanied by a female. Characteristics of hunters' behaviour while hunting are pertinent to assessing current waterfowl management programs.
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Petrie, Mark J., Joseph P. Fleskes, Mike A. Wolder, Craig R. Isola, Gregory S. Yarris, and Daniel A. Skalos. "Potential Effects of Drought on Carrying Capacity for Wintering Waterfowl in the Central Valley of California." Journal of Fish and Wildlife Management 7, no. 2 (September 1, 2016): 408–22. http://dx.doi.org/10.3996/082015-jfwm-082.
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Abstract We used the bioenergetics model TRUEMET to evaluate potential effects of California's recent drought on food supplies for waterfowl wintering in the Central Valley under a range of habitat and waterfowl population scenarios. In nondrought years in the current Central Valley landscape, food supplies are projected to be adequate for waterfowl from fall through early spring (except late March) even if waterfowl populations reach North American Waterfowl Management Plan goals. However, in all drought scenarios that we evaluated, food supplies were projected to be exhausted for ducks by mid- to late winter and by late winter or early spring for geese. For ducks, these results were strongly related to projected declines in winter-flooded rice fields that provide 45% of all the food energy available to ducks in the Central Valley in nondrought water years. Delayed flooding of some managed wetlands may help alleviate food shortages by providing wetland food resources better timed with waterfowl migration and abundance patterns in the Central Valley, as well as reducing the amount of water needed to manage these habitats. However, future research is needed to evaluate the impacts of delayed flooding on waterfowl hunting, and whether California's existing water delivery system would make delayed flooding feasible. Securing adequate water supplies for waterfowl and other wetland-dependent birds is among the greatest challenges facing resource managers in coming years, especially in the increasingly arid western United States.
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Hobson, Keith A., Robert B. Brua, William L. Hohman, and Len I. Wassenaar. "Low Frequency of “Double Molt” of Remiges in Ruddy Ducks Revealed by Stable Isotopes: Implications for Tracking Migratory Waterfowl." Auk 117, no. 1 (January 1, 2000): 129–35. http://dx.doi.org/10.1093/auk/117.1.129.
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Abstract Ratios of the stable carbon (δ13C) and hydrogen (δD) isotopes in newly grown remiges of Ruddy Ducks (Oxyura jamaicensis) are influenced by the isotopic character of food types and ambient water. Systematic isotopic foodweb and water differences between coastal wintering grounds and prairie breeding grounds of Ruddy Ducks provide the basis for using isotopic analyses of feathers to trace the location and timing of molt. Anecdotal evidence, based largely on captive birds, suggests that Ruddy Ducks replace their remiges twice each year (once each on the breeding and wintering grounds), but a recent literature analysis indicates that this phenomenon is rare. Thus, we investigated the extent to which a biannual molt of the remiges occurs in the wild and at the population level. We analyzed the stable isotopes of carbon (n = 57 birds) and hydrogen (n = 50 birds) in flight feathers to estimate the prevalence of the so-called “double molt” of remiges in free-living Ruddy Ducks. Our data showed that natural populations of Ruddy Ducks express an overwhelming unimodal distribution of isotope ratios in their remiges, suggesting that they undergo a single molt at or near the breeding grounds. Only 3 to 6 of 50 birds from Manitoba showed isotopic evidence consistent with growing remiges on the wintering grounds. Feathers from Ruddy Ducks harvested during the fall in the Mississippi Flyway had isotopic profiles consistent with growth on northern freshwater breeding sites. Thus, our results confirm that the replacement of remiges twice each year by Ruddy Ducks is rare, and they suggest that this dual stable-isotope technique can be used to infer general molting origins of North American waterfowl.
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NOURANI, ELHAM, MOHAMMAD KABOLI, and BEN COLLEN. "An assessment of threats to Anatidae in Iran." Bird Conservation International 25, no. 2 (August 26, 2014): 242–57. http://dx.doi.org/10.1017/s0959270914000264.
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SummaryThe network of wetland systems in Iran provides valuable staging and wintering areas for waterbirds in the African-Western Eurasian flyways. The West Siberian/Caspian/Nile populations of Anatidae (ducks, geese and swans) regularly overwinter and stop over in Iran, and are considered an economically and culturally important group of birds in the country. Conservation of such migratory birds requires the identification of key threat factors impacting them throughout the flyway. Since documented data on the status and threats facing Anatidae in Iran are very scarce, in this paper, we attempted to determine the general population trends for the 26 Anatidae species in Iran, using annual waterbird census data, and to identify and score the most important threat factors affecting each species, by consulting the top ornithologists and professional birdwatchers in the country by means of a survey. Our results indicate that the most prevalent threats affecting all 26 species are dam construction, water management practices, and hunting. Our results provide the necessary material for Red List assessment of these species at the national level, an important tool for conservation priority setting within Iran and in the flyway.
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Lewis, Nicole L., Theodore C. Nichols, Christina Lilley, Douglas E. Roscoe, and Jan Lovy. "Blood Lead Declines in Wintering American Black Ducks in New Jersey Following the Lead Shot Ban." Journal of Fish and Wildlife Management 12, no. 1 (April 13, 2021): 174–82. http://dx.doi.org/10.3996/jfwm-20-044.
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Abstract Waterfowl managers first recognized the problem of lead poisoning in ducks from the ingestion of spent lead shot (pellets) over 100 years ago. The phaseout of lead shot for waterfowl hunting began in the Atlantic Flyway in the 1970s. Lead shot was subsequently banned throughout the United States and Canada prior to 2000. We compared blood lead levels in American black ducks Anas rubripes wintering in coastal New Jersey in 1978, prior to the lead ban, and in 2017, about 39 years after lead shot was first banned for use in Atlantic coastal marshes and 27 years after it was banned for waterfowl hunting in New Jersey. The prevalence of blood lead >0.2 ppm, a level commonly used to indicate lead exposure, declined nearly fourfold from 1978 (79%) to 2017 (20%). We found no significant differences in the prevalence of birds with blood lead levels >0.2 ppm between sexes in either year or between age classes in 2017. The prevalence of ducks with blood lead levels >1.0 ppm, considered clinically evident toxicity, declined from 19% in 1978 to 1% in 2017. Our study provides further evidence that the ban on the use of lead shot over 20 years ago throughout North America has resulted in lower blood lead levels in waterfowl. Notwithstanding, we still found evidence of lead exposure in black ducks in 2017, which warrants further investigation.
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Bush, Albert O., and John C. Holmes. "Intestinal helminths of lesser scaup ducks: patterns of association." Canadian Journal of Zoology 64, no. 1 (January 1, 1986): 132–41. http://dx.doi.org/10.1139/z86-022.
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The helminth communities of the small intestines of 45 lesser scaup ducks sampled from 13 lakes in Alberta, Canada, were examined for patterns of association among species. A core of eight frequent, numerous, and positively associated species provided a basic similarity across all host individuals. Six of these core species are specialists in lesser scaup, and the other two are generalists in waterfowl. A group of eight moderately frequent and numerous species, which were positively associated with the core species but not with each other, also contributed to this similarity; these secondary species included two specialists in scaup and three generalists in waterfowl. The 36 remaining "satellite species" appeared to be distributed randomly among birds. Variations among communities in individual birds were due largely to (i) differences in the numbers of two suites of helminth species, one using Hyalella azteca and the other Gammarus lacustris as intermediate host; (ii) differences in the numbers of the Hyalella suite, and in the presence or absence of some secondary or satellite species, associated with the lake from which the duck was taken; and (iii) differences in the total numbers of helminths per duck, which may be associated with differential susceptibility of individual ducks.
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O'Toole, D., and M. F. Raisbeck. "Experimentally Induced Selenosis of Adult Mallard Ducks: Clinical Signs, Lesions, and Toxicology." Veterinary Pathology 34, no. 4 (July 1997): 330–40. http://dx.doi.org/10.1177/030098589703400409.
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Selenosis is thought to be a significant problem among waterfowl populations in selenium-contaminated wetlands in the western United States. Chemical analysis of avian tissues is currently the principal basis for diagnosis. The purpose of these two 150-day studies was to establish whether morphological criteria for selenosis could be developed to supplement chemical analysis. Forty-eight flightling male mallard ducks were fed either a proprietary waterfowl ration (< 1 ppm selenium) or the same ration amended to contain 10, 25, and 60 ppm selenium supplied as seleno-L-methionine ( n = 12/group). In a separate study, 12 birds fed twice daily were offered either a proprietary ration or a selenium-supplemented ration (120 μg/g) for one of two daily feedings. Selenium in whole blood increased from baseline concentrations (< 0.4 μg/ml) to means of 4.5, 8.9, and 16.0 μg/ml in the 10-, 25-, and 60-ppm groups, respectively. All birds in the 60-ppm-dose group rapidly lost weight and were killed (11/12) or died (1/12) between 22 and 50 days of dietary exposure. In addition to emaciation, six of 12 birds (50%) fed the 60-μg/g diet developed mild to moderate generalized hepatopathy with single-cell necrosis, karyomegaly of hepatocytes, hyperplastic bile duct epithelium, and/or iron accumulation in Kupffer cells. The principal lesions in birds exposed to other dietary concentrations of selenium involved integumentary structures containing hard keratin. Gross lesions developed after 76 days of dietary exposure and consisted of bilaterally symmetrical alopecia of the scalp and dorsal cervical midline, broken or lost digital nails, and necrosis of the tip of the beak (maxillary nail). One or more of these three lesions were present in 0/12 birds (0%) fed 10 ppm selenium, 5/12 birds (42%) fed 25 ppm selenium, and 4/9 (44%) birds fed a split-feed diet containing 120 ppm selenium. Controls were unaffected. Histologic lesions in digital and maxillary nails consisted of single-cell to full-thickness necrosis of keratinocytes and multifocal parakeratosis in stratum corneum. Histologic lesions in alopecic skin (necrosis of the epidermal collar, inflammation of the feather pulp, and follicular keratosis) were mild. Some birds with alopecia had no detectable lesions in feather follicles from affected areas of skin. The highest tissue concentrations of selenium were in liver, kidney, and feathers, respectively. Mean hepatic tissue concentrations were 14.5 μg/g (10 ppm group), 29.6 μg/g (25 ppm group), 60.6 μg/g (60 ppm group), 13.0 μg/g (120 ppm split-feed group), and 2.0 μg/g (controls). Integumentary and hepatic lesions may be of value in corroborating a diagnosis of selenosis based on chemical analysis of tissues from naturally intoxicated waterfowl. Some birds with fatal selenosis may have no morphologic lesions other than emaciation.
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Ronconi, Robert A. "Predicting Bird Oiling Events at Oil Sands Tailings Ponds and Assessing the Importance of Alternate Waterbodies for Waterfowl: a Preliminary Assessment." Canadian Field-Naturalist 120, no. 1 (January 1, 2006): 1. http://dx.doi.org/10.22621/cfn.v120i1.237.
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Tailings ponds are an integral part of oil sands mining development in northeastern Alberta, but waterfowl and shorebirds often land in these ponds during spring migration where they may become covered with oil. For decades, managers have developed and implemented methods for deterring birds from landing in these ponds, yet no deterrent strategy is fully effective. Therefore, to enhance deterrence strategies, it will be important to understand the environmental conditions that influence bird use of tailings ponds. This study quantified waterfowl flights over, and use of, tailings ponds and compared this use to waterfowl activity at natural waterbodies in the region over a single spring migration period. Results suggest that waterfowl are most likely to land on tailings ponds before lakes have thawed, after which migratory ducks appeared mainly to use natural waterbodies for migratory stopover sites. Very high numbers of waterfowl were observed on one waterbody, Kearl Lake, suggesting that this lake may be of greater importance to spring staging waterfowl than previously thought. A small sample of birds oiled at tailings ponds were examined in relation to spring weather conditions. Logistic regression analysis demonstrated that the probability of birds being oiled tended to increase with precipitation levels. Results of this study suggest that (1) preservation of natural waterbodies may play an important role in minimizing bird use of tailings ponds, and (2) future bird deterrence efforts should especially aim to deter birds during rainy weather conditions when birds may be more likely to become oiled. These results were from a small sample size, are preliminary in nature, and should be interpreted with caution. A concerted and careful effort to collect and thoroughly analyze long-term records of oiled birds may reveal important environmental effects predicting bird oiling events.
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Szeredi, Levente, Ádám Dán, Nimród Pálmai, Krisztina Ursu, Ádám Bálint, Zsófia Szeleczky, Éva Ivanics, et al. "Tissue tropism of highly pathogenic avian influenza virus subtype H5N1 in naturally infected mute swans ( Cygnus Olor ), domestic geese ( Anser Anser var. domestica ), pekin ducks ( Anas platyrhynchos ) and mulard ducks ( Cairina moschata × anas platyrhynchos )." Acta Veterinaria Hungarica 58, no. 1 (March 1, 2010): 133–45. http://dx.doi.org/10.1556/avet.58.2010.1.14.
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The 2006 epidemic due to highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in Hungary caused the most severe losses in waterfowl which were, according to the literature at the time, supposed to be the most resistant to this pathogen. The presence of pathological lesions and the amount of viral antigen were quantified by gross pathology, histopathology and immunohistochemistry (IHC) in the organs of four waterfowl species [mute swans (n = 10), domestic geese (n = 6), mulard ducks (n = 6) and Pekin ducks (n = 5)] collected during the epidemic. H5N1 subtype HPAIV was isolated from all birds examined. Quantitative real-time reverse transcriptase-polymerase chain reaction (qRRT-PCR) was also applied on a subset of samples [domestic geese (n = 3), mulard (n = 4) and Pekin duck (n = 4)] in order to compare its sensitivity with IHC. Viral antigen was detected by IHC in all cases. However, the overall presence of viral antigen in tissue samples was quite variable: virus antigen was present in 56/81 (69%) swan, 22/38 (58%) goose, 28/46 (61%) mulard duck and 5/43 (12%) Pekin duck tissue samples. HPAIV subtype H5N1 was detected by qRRT-PCR in all birds examined, in 19/19 (100%) goose, 7/28 (25%) mulard duck and 12/28 (43%) Pekin duck tissue samples. As compared to qRRTPCR, the IHC was less sensitive in geese and Pekin ducks but more sensitive in mulard ducks. The IHC was consistently positive above 4.31 log10 copies/reaction but it gave very variable results below that level. Neurotropism of the isolated virus strains was demonstrated by finding the largest amount of viral antigen and the highest average RNA load in the brain in all four waterfowl species examined.
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Latorre-Margalef, Neus, Gunnar Gunnarsson, Vincent J. Munster, Ron A. M. Fouchier, Albert D. M. E. Osterhaus, Johan Elmberg, Björn Olsen, et al. "Effects of influenza A virus infection on migrating mallard ducks." Proceedings of the Royal Society B: Biological Sciences 276, no. 1659 (December 2, 2008): 1029–36. http://dx.doi.org/10.1098/rspb.2008.1501.
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The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas ). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans ( Cygnus columbianus bewickii ) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards ( Anas platyrhynchos ) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002–2007, we collected faecal samples ( n =10 918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales.
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Barnes, Gregory G., and Vernon G. Thomas. "Digestive organ morphology, diet, and guild structure of North American Anatidae." Canadian Journal of Zoology 65, no. 7 (July 1, 1987): 1812–17. http://dx.doi.org/10.1139/z87-274.
Full textAbstract:
Discriminant function, cluster, and covariate analyses of gizzard, small intestine, and ceca weights were used to quantify the structure of feeding guilds and the effects of diet on gut morphology for 18 species of North American anatids. Guild structure based on gut measurements closely approximated that identified by generalized feeding habits. Herbivorous species such as Brant (Branta bernicla), Gadwall (Anas strepera), Redheads (Aythya americana), Canada Geese (Branta canadensis), and Mallards (Anas platyrhynchos) consistently had heavier gizzards and ceca than carnivorous species such as Common Goldeneye (Bucephala clangula), Bufflehead (Bucephala albeola), Oldsquaw (Clangula hyemalis), and Common Mergansers (Mergus merganser). Omnivorous species such as Lesser Scaup (Aythya afftnis), Greater Scaup (Aythya marila), and American Black Ducks (Anas rubripes) were characterized by heavy gizzards, intermediate ceca, and heavy intestines. The results provide further evidence that intestine size is primarily influenced by overall diet diversity and suggest that gut size may be used to indicate general food habits. The ability of waterfowl to adjust gut sizes and accommodate dietary changes is restricted to ranges dictated by the most frequently eaten foods. Thus, predictions of general food habits can be made without knowledge of the foods being consumed at a particular time and location.
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Greenwood, Hamilton, Robert G. Clark, and Patrick J. Weatherhead. "Condition bias of hunter-shot mallards (Anas platyrhynchos)." Canadian Journal of Zoology 64, no. 3 (March 1, 1986): 599–601. http://dx.doi.org/10.1139/z86-088.
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We tested the hypothesis that hunters using decoys disproportionately shot ducks in poor condition. We compared weights of 316 hunter-shot mallards (Anas platyrhynchos) with those of 156 mallards we collected by jump or pass shooting at a roost. Data were subdivided by age, sex, and sampling period. In support of the hypothesis, in 11 of 12 comparisons, hunter-shot ducks weighed less than ducks collected at the roost and those differences were significant for five of the seven largest samples. Also consistent with the hypothesis, weights of hunter-shot birds were less variable than weights of birds collected at the roost in 9 of 12 comparisons. Through the fall collection period, the mean weight of ducks shot by hunters remained constant, while the weight of ducks sampled at the roost increased by 5.4%. Our results support the argument that caution must be exercised when using data from hunter-shot waterfowl for management programs based on band-recovery analysis or for any other purpose for which a condition bias could influence the interpretation of those data.
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Chang, Fei-Fei, Chang-Chieh Chen, Shao-Hung Wang, and Chiou-Lin Chen. "Epidemiology and antibiogram of Riemerella anatipestifer isolated from waterfowl slaughterhouses in Taiwan." Journal of Veterinary Research 63, no. 1 (March 1, 2019): 79–86. http://dx.doi.org/10.2478/jvetres-2019-0003.
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Abstract Introduction: Laryngeal swab samples collected from three waterfowl slaughterhouses in central Taiwan were cultured and suspected isolates of Riemerella anatipestifer were identified by API 20NE and 16S rDNA PCR. Material and Methods: Serum agglutination was used for serotyping, and antimicrobial susceptibility was tested. Results: Seventy-six R. anatipestifer isolates were detected, and the prevalences in the ducks and geese were 12.3% (46/375) and 8.0% (30/375), respectively. The positive isolation rates were 65.6% for all arriving waterfowl, 76.0% for birds in the holding area, 1.6% for defeathered carcasses, but zero for degummed carcasses. A PCR examination detected R. anatipestifer in the slaughtering area frequently. Serotype B was dominant in both duck (34.8%) and goose (46.7%) isolates, but the wide serotype distribution may very well impede vaccination development. All isolates were resistant to colistin, and 79.7% were resistant to more than three common antibiotics. Conclusion: The results proved that most ducks had encountered antibiotic-resistant R. anatipestifer in rearing, which suggests that the bacterium circulates in asymptomatic waterfowl. It is worth noting that most waterfowl farms were found to harbour R. anatipestifer, and contaminated slaughterhouses are a major risk factor in its spread. Effective prevention and containment measures should be established there to interrupt the transmission chain of R. anatipestifer.
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Wasilewski, Rafał, Dariusz Kokoszyński, Anna Mieczkowska, Zenon Bernacki, and Alina Górska. "Structure of the digestive system of ducks depending on sex and genetic background." Acta Veterinaria Brno 84, no. 2 (2015): 153–58. http://dx.doi.org/10.2754/avb201584020153.
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The aim of the study was to determine the effect of genotype and sex on body weight, body dimensions, intestinal length and diameter, percentage of intestinal segments, and weight and percentage of the main internal organs of ducks. The study was performed with 80 Pekin ducks, which were kept throughout rearing (1–49 days of age) in a confinement building and fed commercial waterfowl feed ad libitum. After 7 weeks of rearing, 40 ducks (10 drakes and 10 ducks of hybrid line SM3 Heavy and 10 drakes and 10 ducks of hybrid line AF51) were selected for slaughter. Birds were measured for body length and trunk length. During evisceration, the digestive tract and other internal organs were separated. At 7 weeks of age, SM3 Heavy broilers were heavier and had longer body length and trunk length compared to AF51 ducks. Significant differences were found for body weight in females and for body length in males. The AF 51 females were characterized by significantly greater intestinal length to body length and intestinal length to trunk length ratios, whereas AF51 males showed a greater (P ≤ 0.05) body length to trunk length ratio compared to SM3 Heavy birds. Genetic background of the ducks had no significant effect on the length of intestine and its segments, the diameter of different intestinal segments, and the weight and proportion of the gizzard, liver, heart and spleen. The same pattern was observed for the sex of birds except for gizzard weight, which was significantly greater in SM3 Heavy males than females.
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Pantin-Jackwood, Mary J., Mar Costa-Hurtado, Eric Shepherd, Eric DeJesus, Diane Smith, Erica Spackman, Darrell R. Kapczynski, David L. Suarez, David E. Stallknecht, and David E. Swayne. "Pathogenicity and Transmission of H5 and H7 Highly Pathogenic Avian Influenza Viruses in Mallards." Journal of Virology 90, no. 21 (August 24, 2016): 9967–82. http://dx.doi.org/10.1128/jvi.01165-16.
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ABSTRACTWild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 (Gs/GD) lineage during 2005, 2010, and 2014, but dispersion by wild waterfowl has not been implicated with spread of other HPAI viruses. To better understand why Gs/GD H5 HPAI viruses infect and transmit more efficiently in waterfowl than other HPAI viruses, groups of mallard ducks were challenged with one of 14 different H5 and H7 HPAI viruses, including a Gs/GD lineage H5N1 (clade 2.2) virus from Mongolia, part of the 2005 dispersion, and the H5N8 and H5N2 index HPAI viruses (clade 2.3.4.4) from the United States, part of the 2014 dispersion. All virus-inoculated ducks and contact exposed ducks became infected and shed moderate to high titers of the viruses, with the exception that mallards were resistant to Ck/Pennsylvania/83 and Ck/Queretaro/95 H5N2 HPAI virus infection. Clinical signs were only observed in ducks challenged with the H5N1 2005 virus, which all died, and with the H5N8 and H5N2 2014 viruses, which had decreased weight gain and fever. These three viruses were also shed in higher titers by the ducks, which could facilitate virus transmission and spread. This study highlights the possible role of wild waterfowl in the spread of HPAI viruses.IMPORTANCEThe spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the Gs/GD lineage by migratory waterfowl is a serious concern for animal and public health. H5 and H7 HPAI viruses are considered to be adapted to gallinaceous species (chickens, turkeys, quail, etc.) and less likely to infect and transmit in wild ducks. In order to understand why this is different with certain Gs/GD lineage H5 HPAI viruses, we compared the pathogenicity and transmission of several H5 and H7 HPAI viruses from previous poultry outbreaks to Gs/GD lineage H5 viruses, including H5N1 (clade 2.2), H5N8 and H5N2 (clade 2.3.4.4) viruses, in mallards as a representative wild duck species. Surprisingly, most HPAI viruses examined in this study replicated well and transmitted among mallards; however, the three Gs/GD lineage H5 HPAI viruses replicated to higher titers, which could explain the transmission of these viruses in susceptible wild duck populations.
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Roshier, David A., and Martin W. Asmus. "Use of satellite telemetry on small-bodied waterfowl in Australia." Marine and Freshwater Research 60, no. 4 (2009): 299. http://dx.doi.org/10.1071/mf08152.
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The nomadic or dispersive movements of many Australian waterfowl in response to irregular environmental cues make satellite telemetry studies the only means by which these long-distance movements can be tracked in real time. Unlike some large-bodied soaring species, attaching satellite transmitters to small-bodied waterfowl (<1 kg) is not straightforward because ducks have high wing loadings and need to maintain active flapping to stay aloft. In the present paper, we detail one harness design and attachment method that enabled us to track grey teal (Anas gracilis) for up to 879 days. In addition, we detail rates of data loss, changes in data quality over time and variation in data quality from solar-powered satellite-tags deployed on ducks in Australia and Papua New Guinea. Up to 68% of all locational fixes have a nominal accuracy of less than 1 km, and satellite-tags deployed on wild birds can provide up to 22 location fixes per day and store enough energy during the day to run continuously throughout the night.
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Trovão, Nídia S., Jacqueline M. Nolting, Richard D. Slemons, Martha I. Nelson, and Andrew S. Bowman. "The Evolutionary Dynamics of Influenza A Viruses Circulating in Mallards in Duck Hunting Preserves in Maryland, USA." Microorganisms 9, no. 1 (December 25, 2020): 40. http://dx.doi.org/10.3390/microorganisms9010040.
Full textAbstract:
Duck hunting preserves (DHP) have resident populations of farm-raised mallard ducks, which create potential foci for the evolution of novel influenza A viruses (IAVs). Through an eleven-year (2003–2013) IAV surveillance project in seven DHPs in Maryland, USA, we frequently identified IAVs in the resident, free-flying mallard ducks (5.8% of cloacal samples were IAV-positive). The IAV population had high genetic diversity, including 12 HA subtypes and 9 NA subtypes. By sequencing the complete genomes of 290 viruses, we determined that genetically diverse IAVs were introduced annually into DHP ducks, predominantly from wild birds in the Anatidae family that inhabit the Atlantic and Mississippi flyways. The relatively low viral gene flow observed out of DHPs suggests that raised mallards do not sustain long-term viral persistence nor do they serve as important sources of new viruses in wild birds. Overall, our findings indicate that DHPs offer reliable samples of the diversity of IAV subtypes, and could serve as regional sentinel sites that mimic the viral diversity found in local wild duck populations, which would provide a cost-efficient strategy for long-term IAV monitoring. Such monitoring could allow for early identification and characterization of viruses that threaten bird species of high economic and environmental interest.
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Rohwer, Frank C. "Inter and Intraspecific Relationships between Egg Size and Clutch Size in Waterfowl." Auk 105, no. 1 (January 1, 1988): 161–76. http://dx.doi.org/10.1093/auk/105.1.161.
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Abstract Lack (1967, 1968a) proposed that clutch size of waterfowl and other birds with self-feeding young was limited by females' ability to produce eggs. Lack supported this egg-production hypothesis by showing a strong inverse relationship between egg size and clutch size within and among species of waterfowl. A reanalysis using updated data and more appropriate statistics failed to confirm Lack's results. Grouping all the waterfowl produced a weak (r2 = 0.13 inverse relationship between relative egg size and relative clutch size. This relationship was due mainly to a handful of ducks that nest on oceanic islands. Analyses by tribes showed that relative egg size and relative clutch size were inversely related in only 2 of the 8 major tribes of waterfowl. Finally, intraspecific analyses failed to reveal a trade-off between egg size and clutch size in Blue-winged Teal (Anas discors) and Northern Shovelers (A. clypeata). Similar intraspecific analyses for 12 other waterfowl have failed to show the predicted inverse relationship between egg size and clutch size. These results suggest that the widely accepted egg-production hypothesis may be considerably overemphasized.
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Namgail, Tsewang, John Y. Takekawa, Sivananinthaperumal Bala-Chandran, Ponnusamy Sathiyaselvam, Taej Mundkur, and Scott H. Newman. "Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size." Current Zoology 60, no. 5 (October 1, 2014): 616–21. http://dx.doi.org/10.1093/czoolo/60.5.616.
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Abstract Relationship between species’ home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.
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Goulart, M. A., C. S. Braga, C. Lira, D. B. Amorim, A. S. Macedo, and M. M. Alievi. "Intercostal celiotomy for removal of proventriculus foreign body in muscovy duck (Cairina moschata): case report." Arquivo Brasileiro de Medicina Veterinária e Zootecnia 71, no. 3 (June 2019): 805–10. http://dx.doi.org/10.1590/1678-4162-10044.
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ABSTRACT Ducks, geese and swans are included in the Anatidae family, Anseriformes order. The leading injuries causes to waterfowl are tangling in fishing materials and foreign bodies ingestion. A muscovy duck (Cairina moschata) was referred for treatment at Veterinary Teaching Hospital and a radiographic examination showed the presence of a hook in the coelom. Surgical exposure and incision of the proventriculus was made through left intercostal access and the hook along with a fishing line were gently removed. The animal began to feed voluntarily at the fourth post-operative day and two weeks after the procedure the patient was clinically well and was released to wild. This surgical approach differs in some aspects from the listed techniques in the known literature. It proved to be a viable and appropriate alternative to treat this affection since it did not cause any trans- or post-operative complications and enabled rapid recovery and subsequent patient release.
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Stroud, David A., Deborah J. Pain, and Rhys E. Green. "Evidence of widespread illegal hunting of waterfowl in England despite partial regulation of the use of lead shotgun ammunition." Conservation Evidence Journal 18 (January 1, 2021): 18–24. http://dx.doi.org/10.52201/cej18grkf2551.
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Shooting of birds using lead shotgun ammunition was legal for all quarry species in the UK until 1st September 1999, when the Environmental Protection (Restriction on Use of Lead Shot) (England) Regulations 1999 and similar regulations in other UK countries came into effect. These regulations made it illegal to shoot ducks and geese and some other waterfowl species in England with lead shotgun ammunition and/or to use it in certain wetland habitats. The legislation was intended to reduce the incidence of lead poisoning of wetland birds caused by ingested and embedded shotgun pellets. We evaluate the effectiveness of this legislation by estimating the number of ducks shot in England with lead shot. We also assess the effectiveness of awareness-raising actions about the regulations, including an advocacy campaign intended to encourage compliance, and an undertaking by the UK Government to examine ways to improve compliance and enforcement. We estimate that about 13 million ducks have been shot illegally using lead shotgun ammunition in England since 1st September 1999 - an annual average of approximately 586,000 and representing approximately 70% of the total ducks shot. There was no detectable decline in the number of ducks killed using lead shotgun ammunition following the awareness-raising publicity and advocacy campaign by shooting and countryside management organisations. The government review of implementation and enforcement of the Regulations on the level of this wildlife crime was not followed by any new prosecutions. There has been one prosecution for an offence under the Lead Shot Regulations. We conclude that the 1999 Regulations and attempts to promote compliance with them have effected only a small reduction in the use of lead shotgun ammunition in wetlands in England.
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Kokoszyński, D., and Z. Bernacki. "Comparison of some meat traits in ducks from two conservative flocks." Archives Animal Breeding 53, no. 4 (October 10, 2010): 484–93. http://dx.doi.org/10.5194/aab-53-484-2010.
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Abstract. Eighty Pekin ducks from P11 and P22 conservative flocks (40 birds of each strain, including 20 males and 20 females) were investigated. Ducks were raised in a confinement building and fed ad libitum standard diets for waterfowl. At 7 weeks of age, 5 males and 5 females from each strain were slaughtered and dissected. Breast and leg muscles were sampled to determine fatty acid profile and selected minerals. Compared to P22 ducks, P11 ducks showed higher body weight at 7 weeks of age and higher rate of growth paralleled by better feed conversion ratio (kg feed/kg gain), higher dressing percentage, lower proportion (%) of leg muscles and lower proportion of all carcass muscles. Differences in these traits were not significant. Breast muscles of P11 ducks had significantly more C24:0 and C20:4 acids and leg muscles contained significantly more C14:0, C16:1, C18:1 and C24:0 acids compared to P22 ducks. In addition, leg muscles of P11 ducks had a significantly lower proportion of C17:0, C18:0, C24:0 and C22:4 compared to the same muscles of P22 birds. Leg muscles of P11 ducks had significantly more monounsaturated fatty acids (MUFA), higher unsaturated to saturated fatty acid (UFA/SFA) and polyunsaturated to saturated fatty acid ratios (PUFA/SFA), and significantly less saturated fatty acids (SFA) compared to P22 ducks. The Na, K, Mg, Fe, Cu and Zn content of duck muscles was similar in both lines. Compared to leg muscles, breast muscles of P11 and P22 ducks were found to contain significantly more iron (Fe) and copper (Cu), and less zinc (Zn).
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Varner, Dana M., Aaron T. Pearse, Andrew A. Bishop, Jonas I. Davis, John C. Denton, Roger C. Grosse, Heather M. Johnson, et al. "Roosting Habitat Use by Sandhill Cranes and Waterfowl on the North and South Platte Rivers in Nebraska." Journal of Fish and Wildlife Management 11, no. 1 (December 3, 2019): 56–67. http://dx.doi.org/10.3996/042019-jfwm-030.
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Abstract Migration ecology and habitat use of spring migrating birds using the Central Platte River is a well-explored topic, yet less is known about use of the North and South Platte rivers (NSPR) in western Nebraska. The efficiency and effectiveness of conservation efforts in the NSPR could be greatly improved with access to information about where and when birds roost and landscape prioritization tools. We used aerial surveys to determine population distribution and migration phenology of sandhill cranes Antigone canadensis, Canada geese Branta canadensis, and ducks using the NSPR for roosting during the mid-February to mid-April spring migration. We used these data and geospatial information to identify important river reaches for these species and habitat covariates that discriminate between those used at lower and higher densities. We found that sandhill cranes and waterfowl generally roosted in different segments of the NSPR and, subsequently, different factors were associated with high densities. Sandhill crane density was positively correlated with distance from obstructions greater than 1 m high and negatively correlated with area of unvegetated sandbar within 1 km. Density of Canada geese and ducks was high in segments positively associated with wetland and sand pit habitats. Human disturbance variables such as roads and bridges in this rural region had little effect on identification of roosting areas used by high densities of all groups. On the basis of our results, habitat conservation efforts that specifically target sandhill cranes will not have similar positive effects on waterfowl use and distribution in the NSPR. Our identification of the most important river segments should allow managers to better target land acquisition or management resources to areas that will have the greatest effect on either waterfowl or sandhill cranes during spring migration.
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Hepp, Gary R. "Effects of Body Weight and Age on the Time of Pairing of American Black Ducks." Auk 103, no. 3 (July 1, 1986): 477–84. http://dx.doi.org/10.1093/auk/103.3.477.
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Abstract I used captive young and adult American Black Ducks (Anas rubripes) during October-February 1984-1985 to test whether body weight and age affected time of pair-bond formation. Eighty ducks were marked individually, and 10 ducks (6 males and 4 females, half of each age class) were assigned to each of 8 experimental pens. Ducks in 4 pens received an ad libitum diet of commercial duck food, and ducks in the other 4 pens received a restricted ration of the same food. During early winter ducks in both groups gained weight, but ducks on the restricted diet gained less than birds on the ad libitum diet; peak winter weight of ducks on the ad libitum diet averaged 22% greater than initial body weight compared with 6.5% for ducks on the restricted diet. In late winter ducks on the restricted diet lost 28.7% of peak winter weight, and ducks on the ad libitum diet lost 19.3%. Weight loss of ducks on the ad libitum diet began before weather conditions became severe and coincided with a reduction in food consumption. This result supports the idea that weight loss of waterfowl in late winter is controlled endogenously. Individuals on the ad libitum diet paired earlier than those on the restricted diet, and pair bonds were stronger. Adults of both sexes paired earlier than young ducks, but differences for females were not significant statistically. Age and energy constraints are factors that can affect intraspecific variation in pairing chronology.
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FULLER, T. L., M. F. DUCATEZ, K. Y. NJABO, E. COUACY-HYMANN, A. CHASAR, G. L. APLOGAN, S. LAO, et al. "Avian influenza surveillance in Central and West Africa, 2010–2014." Epidemiology and Infection 143, no. 10 (December 22, 2014): 2205–12. http://dx.doi.org/10.1017/s0950268814003586.
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SUMMARYAvian influenza virus (AIV) is an important zoonotic pathogen, resulting in global human morbidity and mortality and substantial economic losses to the poultry industry. Poultry and wild birds have transmitted AIV to humans, most frequently subtypes H5 and H7, but also different strains and subtypes of H6, H9, and H10. Determining which birds are AIV reservoirs can help identify human populations that have a high risk of infection with these viruses due to occupational or recreational exposure to the reservoir species. To assess the prevalence of AIV in tropical birds, from 2010 to 2014, we sampled 40 099 birds at 32 sites in Central Africa (Cameroon, Central African Republic, Congo-Brazzaville, Gabon) and West Africa (Benin, Côte d'Ivoire, Togo). In Central Africa, detection rates by real-time RT–PCR were 16·6% in songbirds (eight passerine families,n = 1257), 16·4% in kingfishers (family Alcedinidae,n = 73), 8·2% in ducks (family Anatidae,n = 564), and 3·65% in chickens (family Phasianidae,n = 1042). Public health authorities should educate human cohorts that have high exposure to these bird populations about AIV and assess their adherence to biosecurity practices, including Cameroonian farmers who raise small backyard flocks.
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Cooke, Fred, Gregory J. Robertson, Cyndi M. Smith, R. Ian Goudie, and W. Sean Boyd. "Survival, Emigration, and Winter Population Structure of Harlequin Ducks." Condor 102, no. 1 (February 1, 2000): 137–44. http://dx.doi.org/10.1093/condor/102.1.137.
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AbstractA population of individually marked Harlequin Ducks (Histrionicus histrionicus) at White Rock, British Columbia, Canada was examined to measure the degree of population differentiation among birds which pair during the winter months. This required an understanding of the patterns of emigration among wintering sites in different segments of the population. Some juveniles arrived at the wintering grounds accompanied by their mothers, thus initially arriving into the same winter population as their parents. Young males were more likely than young females to disperse during the first two years of life. Adult males had higher local survival than adult females during the summer months, probably because of the greater mortality risks to nesting females. During the nonbreeding seasons, local survival was the same in both sexes. Paired males had a local survival of more than 90%, suggesting both high survival and strong philopatry. Unpaired males had a lower local survival rate, suggesting they have higher mortality and/or emigration rates. Young females had the same local survival rate as adult females, suggesting that they did not disperse during the winter. These winter philopatry patterns are similar to the general pattern of breeding philopatry in waterfowl, with females showing stronger philopatry than males, and paired adults stronger philopatry than unpaired and young birds. The dispersal of young males makes local population differentiation unlikely in this species.
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Gillman, Anna, Marie Nykvist, Shaman Muradrasoli, Hanna Söderström, Michelle Wille, Annika Daggfeldt, Caroline Bröjer, Jonas Waldenström, Björn Olsen, and Josef D. Järhult. "Influenza A(H7N9) Virus Acquires Resistance-Related Neuraminidase I222T Substitution When Infected Mallards Are Exposed to Low Levels of Oseltamivir in Water." Antimicrobial Agents and Chemotherapy 59, no. 9 (June 15, 2015): 5196–202. http://dx.doi.org/10.1128/aac.00886-15.
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ABSTRACTInfluenza A virus (IAV) has its natural reservoir in wild waterfowl, and new human IAVs often contain gene segments originating from avian IAVs. Treatment options for severe human influenza are principally restricted to neuraminidase inhibitors (NAIs), among which oseltamivir is stockpiled in preparedness for influenza pandemics. There is evolutionary pressure in the environment for resistance development to oseltamivir in avian IAVs, as the active metabolite oseltamivir carboxylate (OC) passes largely undegraded through sewage treatment to river water where waterfowl reside. In anin vivomallard (Anas platyrhynchos) model, we tested if low-pathogenic avian influenza A(H7N9) virus might become resistant if the host was exposed to low levels of OC. Ducks were experimentally infected, and OC was added to their water, after which infection and transmission were maintained by successive introductions of uninfected birds. Daily fecal samples were tested for IAV excretion, genotype, and phenotype. Following mallard exposure to 2.5 μg/liter OC, the resistance-related neuraminidase (NA) I222T substitution, was detected within 2 days during the first passage and was found in all viruses sequenced from subsequently introduced ducks. The substitution generated 8-fold and 2.4-fold increases in the 50% inhibitory concentration (IC50) for OC (P< 0.001) and zanamivir (P= 0.016), respectively. We conclude that OC exposure of IAV hosts, in the same concentration magnitude as found in the environment, may result in amino acid substitutions, leading to changed antiviral sensitivity in an IAV subtype that can be highly pathogenic to humans. Prudent use of oseltamivir and resistance surveillance of IAVs in wild birds are warranted.
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Fedynich, Alan M., Danny B. Pence, Paul N. Gray, and James F. Bergan. "Helminth community structure and pattern in two allopatric populations of a nonmigratory waterfowl species (Anas fulvigula)." Canadian Journal of Zoology 74, no. 7 (July 1, 1996): 1253–59. http://dx.doi.org/10.1139/z96-139.
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Helminth communities of mottled ducks (Anas fulvigula) from Florida and Texas were species rich and diverse. The helminth component community in the mottled duck population from Texas contained more species than were found in the Florida host population. However, infracommunities of birds from Florida and Texas contained 9.5 ± 0.7 (mean ± SE) and 9.3 + 0.7 species, respectively. Similarity indices indicated less commonality of helminth species between the 2 host populations; 23 of the 42 species found across the 2 populations co-occurred. Eight helminth species from each host population were recurrent group or associate members; however, only 3 species (Amidostomum acutum, Capillaria contorta, and Tetrameres spp.) maintained group membership across both host populations. Maritrema paracadiae and Psilochasmus oxyurus were absent in birds from Florida but were recurrent group members in the host population from Texas. Only 2 recurrent group members (A. acutum and Epomidiostomum uncinatum) in birds from Florida were members of the same feeding guild and shared the same microhabitat. Three distinct feeding guilds, each containing 2 species, were found in birds from Texas. Results suggest that habitat diversity of the host plays an important part in determining species richness; however, important helminth species in both mottled duck populations are those commonly found in other Anatini from North America.
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Bryant, D. M. "Wading birds and wildfowl of the estuary and Firth of Forth, Scotland." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 93, no. 3-4 (1987): 509–20. http://dx.doi.org/10.1017/s0269727000006916.
Full textAbstract:
SynopsisThe estuary and Firth of Forth support an outstanding number and variety of wildfowl and waders at migration seasons and in midwinter. Although populations of wildfowl and waders fell from 25–35,000 and 50–65,000 respectively in the 1970s, to 10–15,000 and 30–40,000 by the mid-1980s, the Forth remains one of few British estuaries to support more than fifteen waterfowl species of national importance for conservation. The ecology and decline of diving ducks off Edinburgh and population studies of shelduck have been given particular attention by researchers. Among waders, distributions, movements and feeding have been studied in detail. The causes of the recent declines amongst waders, notably for knot (Calidris canutus) and dunlin (Calidris alpina) on the estuarine Forth, remain uncertain, but are likely to include natural factors as well as those linked to man's activities.
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Fleskes, Joseph P., Andrew M. Ramey, Andrew B. Reeves, and Julie L. Yee. "Body Mass, Wing Length, and Condition of Wintering Ducks Relative to Hematozoa Infection." Journal of Fish and Wildlife Management 8, no. 1 (February 1, 2017): 89–100. http://dx.doi.org/10.3996/082016-jfwm-063.
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Abstract Waterfowl managers lack information regarding factors that may be reducing the positive response of waterfowl body condition to habitat improvements. Protozoan blood parasites (i.e., hematozoa) are commonly found in birds and have been related to reduced body mass, wing length, and body condition. We studied relationships between 12 measures of hematozoa infection and body mass, wing length, and body mass divided by wing length (i.e., body condition index) of the five most common duck species (northern pintail [Anas acuta], mallard [A. platyrhynchos], green-winged teal [A. crecca], American wigeon [A. americana], northern shoveler [A. clypeata]) wintering in the Central Valley of California during October 2006–January 2007. After accounting for variation due to species, age–sex cohort, Central Valley region, and month, wing length, body mass, and body condition index were found to be negatively related to infection by Leucocytozoon and by “any hematozoa” but not related to infection by only Plasmodium or Haemoproteus, or coinfections of greater than one genus or parasite haplotype (albeit few ducks had Plasmodium or Haemoproteus infection or coinfections). Evidence of a negative relationship with infection was stronger for body mass and body condition index than for wing length and indicated that the relationships varied among species, age–sex cohorts, regions, and months. Compared with uninfected ducks, hematozoa-infected duck body mass, wing length, and body condition index was −1.63% (85% CI = −2.79% to −0.47%), −0.12% (−0.41% to 0.17%), and −1.38% (−2.49% to −0.26%), respectively. Although seemingly small, the −1.63% difference in body mass represents a large percentage (e.g., 38% for northern pintail) of the observed increase in wintering duck body mass associated with Central Valley habitat improvements. Because infection prevalence and relationship to body condition might change over time because of climate or other factors, tracking hematozoa infection prevalence might be important to inform and accurately assess the effect of conservation programs designed to improve waterfowl body condition.
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Kingsford, RT, J. Flanjack, and S. Black. "Lead Shot and Ducks on Lake Cowal." Wildlife Research 16, no. 2 (1989): 167. http://dx.doi.org/10.1071/wr9890167.
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We determined the amount of lead shot left after shooting, in the sediment and also the occurrence of lead shot in the gizzards of waterfowl shot at Lake Cowal. We also investigated levels of lead in livers. Livers and gizzards of 342 ducks, Pacific black duck (96), grey teal (122), maned duck (102), pink-eared duck (15) and Australasian shoveler (7), were collected during the 1987 duck shooting season. Few birds had ingested shot (1.5%). Black ducks had more grit, the size of shot, in their gizzards than did grey teal or maned duck. Total grit contents in the gizzards were of a similar weight for black duck and maned ducks but less for grey teal. Two ducks had lead levels in the liver indicative of lead poisoning (>6 ppm) wet weight. Lead levels in the liver were generally low, 0.32 � 0.76 ppm (mean + s.d.). There were no differences between species or sexes in levels of lead in livers. There was also no difference between lead levels of ducks shot on opening day compared to those shot 4 weeks later. Crude density estimates, extrapolated from 77 samples of sediment (800 cm2), averaged 16 000 shot per hectare for areas close to where hunters camped. Crude density, extrapolated from 100 samples, was 3400 shot per hectare for areas of low hunter density.
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Circella, Elena, Antonio Camarda, Luca Bano, Giacomo Marzano, Roberto Lombardi, Francesco D’Onghia, and Grazia Greco. "Botulism in Wild Birds and Changes in Environmental Habitat: A Relationship to be Considered." Animals 9, no. 12 (November 26, 2019): 1034. http://dx.doi.org/10.3390/ani9121034.
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Any human activity, even if aimed at the improvement of a natural area, can potentially affect wildlife, leading to possible short-term or long-term changes due to the human–wildlife interaction. In this study, a botulism outbreak which occurred in waterfowl in a nature reserve after a conservative environmental action is reported. More than 180 different species of wild birds, including seventy waterfowl species, live in the area. The wildlife reserve rangers built an artificial pond equipped with draining canals in the wetland in order to improve the environment of waterfowl species and to facilitate their supply of food. Then, presumably due to tidal rides, gray mullets (Mugil cephalus) arrived from the sea and settled in the pond. The number of fishes gradually increased, and several fishes died with a peak of mortality in the summer of 2017, creating a great amount of decaying organic material and the optimal conditions for Clostridium botulinum growth and toxin production. A botulism outbreak then occurred rapidly and was characterised by flaccid paralysis and sudden mortality of the birds. Seven mallard ducks (Anas platyrhynchos), 4 common teals (Anas crecca), 1 garganey (Anas querquedula), 2 wood sandpipers (Tringa glareola), 1 little egret (Egretta garzetta), 1 little grebe (Tachybaptus ruficollis), and 4 Eurasian coots (Fulica atra) were found dead. Interestingly, the toxin identified as responsible for the disease outbreak was the mosaic of type C and D toxins (C/D type). The prompt removal of the fish carcasses led to a rapid resolution of the outbreak of the disease, highlighting the relevance of a correct management for any action in environmental contexts. The conclusion is that any human activity in wildlife habitats should be carefully considered in order to assess the possible impacts and to quickly identify the possible risks of changes in wildlife population.
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Meteyer, Carol U., Richard R. Dubielzig, F. Joshua Dein, Laurie A. Baeten, Melody IS Moore, Joseph R. Jehl, and Katherine Wesenberg. "Sodium Toxicity and Pathology Associated with Exposure of Waterfowl to Hypersaline Playa Lakes of Southeast New Mexico." Journal of Veterinary Diagnostic Investigation 9, no. 3 (July 1997): 269–80. http://dx.doi.org/10.1177/104063879700900308.
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Cause of mortality was studied in waterfowl in hypersaline playa lakes of southeast New Mexico during spring and fall migration. Mortality was not common in wild ducks resting on the playas during good weather. However, when birds remained on the lakes for prolonged periods of time, such as during experimental trials and stormy weather, a heavy layer of salt precipitated on their feathers. Sodium toxicity was the cause of death for all experimental mallards housed on playa water and for 50% of the wild waterfowl found moribund or dead during the spring of 1995. Gross lesions included heavy salt precipitation on the feathers, ocular lens opacities, deeply congested brains, and dilated, thin-walled, fluid-filled cloacae. Microscopic lesions in the more severely affected birds included liquefaction of ocular lens cortex with lens fiber swelling and multifocal to diffuse ulcerative conjunctivitis with severe granulocytic inflammation, edema, and granulocytic vasculitis resulting in thrombosis. Inflammation similar to that seen in the conjunctiva occasionally involved the mucosa of the mouth, pharynx, nasal turbinates, cloaca, and bursa. Transcorneal movement of water in response to the hypersaline conditions on the playa lakes or direct contact with salt crystals could induce anterior segment dehydration of the aqueous humor and increased osmotic pressure on the lens, leading to cataract formation.
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Lopsan, H. O. "Dynamics and features of manifestation of highly pathogenic avian influenza in the Republic of Tuva." Siberian Herald of Agricultural Science 50, no. 4 (September 25, 2020): 72–79. http://dx.doi.org/10.26898/0370-8799-2020-4-9.
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The dynamics and features of the manifestation of highly pathogenic avian influenza A/H5N1 were studied on the territory of the Republic of Tuva, where it was first recorded in 2006 in wild migratory waterfowl of the duck family, mainly great crested grebe ducks. In the epizootic process of highly pathogenic avian flu on the territory of the Republic, causal-temporal relationships with the seasonal migration of wild waterfowl from the countries of South-East Asia have been noted. Epizootics of highly pathogenic avian flu were observed in 2006, 2009, 2010, 2014, 2015, 2016. In 2016, as a result of mutation of the H5N1 virus strain, an outbreak of highly pathogenic avian flu of the H5N8 strain was registered. Outbreaks of highly pathogenic avian flu H5 and H7 subtypes simultaneously with low pathogenic subtypes of avian flu H3 were noted in 2014, H9 – in 2013 and 2014. In the study of blood serum of birds in the years officially free from avian flu, antibodies to hemagglutinins of the virus of different subtypes were detected in 11.2-50.0% of cases. Despite the absence of bird mortality, this indicates a constant circulation of avian influenza agent in the body of waterfowl. On the territory of the Republic, avian flu has not spread among poultry due to natural-geographical, socio-economic conditions. The development of distant pasture farming does not provide for the maintenance and breeding of poultry in the unfavorable area of the lake UvsNuur; the local population does not have a tradition of hunting for wild fowl, which prevents contact between wild and domestic birds; there are no lakes or pond reservoirs near the only poultry farm in the Republic with a small stock, which prevents wild waterfowl from entering and passing through flying passages.
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Matczuk, Anna Karolina, Monika Chmielewska-Władyka, Magdalena Siedlecka, Karolina Julia Bednarek, and Alina Wieliczko. "Short Beak and Dwarfism Syndrome in Ducks in Poland Caused by Novel Goose Parvovirus." Animals 10, no. 12 (December 15, 2020): 2397. http://dx.doi.org/10.3390/ani10122397.
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Short beak and dwarfism syndrome (SBDS), which was previously identified only in mule ducks, is now an emerging disease of Pekin ducks in China and Egypt. The disease is caused by the infection of ducks with a genetic variant of goose parvovirus—novel goose parvovirus (nGPV). In 2019, SBDS was observed for the first time in Poland in eight farms of Pekin ducks. Birds in the affected flock were found to show growth retardation and beak atrophy with tongue protrusions. Morbidity ranged between 15% and 40% (in one flock), while the mortality rate was 4–6%. Co-infection with duck circovirus, a known immunosuppressive agent, was observed in 85.7% of ducks. The complete coding regions of four isolates were sequenced and submitted to GenBank. The phylogenetic analysis revealed a close relationship of Polish viral sequences with the Chinese nGPV. Genomic sequence alignments showed 98.57–99.28% identity with the nGPV sequences obtained in China, and 96.42% identity with the classical GPV (cGPV; Derzsy’s disease). The rate of amino acid mutations in comparison to cGPV and Chinese nGPV was higher in the Rep protein than in the Vp1 protein. To our knowledge, this is the first report of nGPV infection in Pekin ducks in Poland and Europe. It should be emphasized that monitoring and sequencing of waterfowl parvoviruses is important for tracking the viral genetic changes that enable adaptation to new species of waterbirds.