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1
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 (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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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 (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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Link, William A., John R. Sauer, and Daniel K. Niven. "A Hierarchical Model for Regional Analysis of Population Change Using Christmas Bird Count Data, with Application to the American Black Duck." Condor 108, no. 1 (2006): 13–24. http://dx.doi.org/10.1093/condor/108.1.13.
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Abstract Analysis of Christmas Bird Count (CBC) data is complicated by the need to account for variation in effort on counts and to provide summaries over large geographic regions. We describe a hierarchical model for analysis of population change using CBC data that addresses these needs. The effect of effort is modeled parametrically, with parameter values varying among strata as identically distributed random effects. Year and site effects are modeled hierarchically, accommodating large regional variation in number of samples and precision of estimates. The resulting model is complex, but a Bayesian analysis can be conducted using Markov chain Monte Carlo techniques. We analyze CBC data for American Black Ducks (Anas rubripes), a species of considerable management interest that has historically been monitored using winter surveys. Over the interval 1966–2003, Black Duck populations showed distinct regional patterns of population change. The patterns shown by CBC data are similar to those shown by the Midwinter Waterfowl Inventory for the United States.
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Обуховська, О. В. "ПРИРОДНІ РЕЗЕРВУАРИ MYCOPLASMA GALLISEPTICUM". Вісник Полтавської державної аграрної академії, № 4 (8 грудня 2012): 107–11. http://dx.doi.org/10.31210/visnyk2012.04.28.
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Доведено, що декоративна та дика птиця можебути природним резервуаром Mycoplasma gallisepticum.За умов утримання на обмеженій територіїптиці різних видів відбувається передача збудникавід типових (курки, індички, фазани) до нетипових(качки, гусаки, лебеді) хазяїв. У такому разі серо-позитивність у водоплавної птиці може сягатизначення 12,73 %, мікоплазманосійство – 5,45 %від усього поголів’я. Виявлено, що в популяціях ди-кої водоплавної птиці (огарів) близько 17 % особинє потенційними мікоплазманосіями.
 It has been proved that decorative and wild bird may be thenatural reservoir of Mycoplasma gallisepticum. It has beenprovided that content for the limited territory of birds ofdifferent species of parasite transmission occurs from the typical(chickens, turkeys, pheasants) to the unusual (ducks, geese,swans). The seropositivity among waterfowl can reach values of12.73 %, the mikoplazmacarrier – 5.45 % of the total population. It was revealed that in populations of wildwaterfowl (ogarej) up to 17 % of individuals are potentialmikoplazmacarriers.
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Pantin-Jackwood, Mary J., Mar Costa-Hurtado, Eric Shepherd, et al. "Pathogenicity and Transmission of H5 and H7 Highly Pathogenic Avian Influenza Viruses in Mallards." Journal of Virology 90, no. 21 (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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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 (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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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 (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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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 (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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Huang, Yanyan, Michelle Wille, Ashley Dobbin, et al. "A 4-year study of avian influenza virus prevalence and subtype diversity in ducks of Newfoundland, Canada." Canadian Journal of Microbiology 59, no. 10 (2013): 701–8. http://dx.doi.org/10.1139/cjm-2013-0507.
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The island of Newfoundland, Canada, is at the eastern edge of North America and has migratory bird connections with the continental mainland as well as across the North Atlantic Ocean. Here, we report a 4-year avian influenza virus (AIV) epidemiological study in ducks in the St. John’s region of Newfoundland. The overall prevalence of AIV detection in ducks during this study was 7.2%, with American Black Ducks contributing the vast majority of the collected samples and the AIV positives. The juvenile ducks showed a significantly higher AIV detection rate (10.6%) compared with adults (3.4%). Seasonally, AIV prevalence rates were higher in the autumn (8.4%), but positives were still detected in the winter (4.6%). Preliminary serology tests showed a high incidence of previous AIV infection (20/38, 52.6%). A total of 43 viruses were characterized for their HA–NA or HA subtypes, which revealed a large diversity of AIV subtypes and little recurrence of subtypes from year to year. Investigation of the movement patterns of ducks in this region showed that it is a largely non-migratory duck population, which may contribute to the observed pattern of high AIV subtype turnover. Phylogenetic analysis of 4 H1N1 and one H5N4 AIVs showed these viruses were highly similar to other low pathogenic AIV sequences from waterfowl in North America and assigned all gene segments into American-avian clades. Notably, the H1N1 viruses, which were identified in consecutive years, possessed homologous genomes. Such detection of homologous AIV genomes across years is rare, but indicates the role of the environmental reservoir in viral perpetuation.
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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 (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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Kim, Jeong-Ki, Patrick Seiler, Heather L. Forrest, et al. "Pathogenicity and Vaccine Efficacy of Different Clades of Asian H5N1 Avian Influenza A Viruses in Domestic Ducks." Journal of Virology 82, no. 22 (2008): 11374–82. http://dx.doi.org/10.1128/jvi.01176-08.
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ABSTRACT Waterfowl represent the natural reservoir of all subtypes of influenza A viruses, including H5N1. Ducks are especially considered major contributors to the spread of H5N1 influenza A viruses because they exhibit diversity in morbidity and mortality. Therefore, as a preventive strategy against endemic as well as pandemic influenza, it is important to reduce the spread of H5N1 influenza A viruses in duck populations. Here, we describe the pathogenicity of dominant clades (clades 1 and 2) of H5N1 influenza A viruses circulating in birds in Asia. Four representatives of dominant clades of the viruses cause symptomatic infection but lead to different profiles of lethality in domestic ducks. We also demonstrate the efficacy, cross-protectiveness, and immunogenicity of three different inactivated oil emulsion whole-virus H5 influenza vaccines (derived by implementing reverse genetics) to the viruses in domestic ducks. A single dose of the vaccines containing 1 μg of hemagglutinin protein provides complete protection against a lethal A/Duck/Laos/25/06 (H5N1) influenza virus challenge, with no evidence of morbidity, mortality, or shedding of the challenge virus. Moreover, two of the three vaccines achieved complete cross-clade or cross-subclade protection against the heterologous avian influenza virus challenge. Interestingly, the vaccines induce low or undetectable titers of hemagglutination inhibition (HI), cross-HI, and/or virus neutralization antibodies. The mechanism of complete protection in the absence of detectable antibody responses remains an open question.
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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 (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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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.
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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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Świętoń, Edyta, Karolina Tarasiuk, Monika Olszewska-Tomczyk, Ewelina Iwan, and Krzysztof Śmietanka. "A Turkey-origin H9N2 Avian Influenza Virus Shows Low Pathogenicity but Different Within-host Diversity in Experimentally Infected Turkeys, Quail and Ducks." Viruses 12, no. 3 (2020): 319. http://dx.doi.org/10.3390/v12030319.
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Avian influenza virus (AIV) is a highly diverse and widespread poultry pathogen. Its evolution and adaptation may be affected by multiple host and ecological factors, which are still poorly understood. In the present study, a turkey-origin H9N2 AIV was used as a model to investigate the within-host diversity of the virus in turkeys, quail and ducks in conjunction with the clinical course, shedding and seroconversion. Ten birds were inoculated oculonasally with a dose of 106 EID50 of the virus and monitored for 14 days. Virus shedding, transmission and seroconversion were evaluated, and swabs collected at selected time-points were characterized in deep sequencing to assess virus diversity. In general, the virus showed low pathogenicity for the examined bird species, but differences in shedding patterns, seroconversion and clinical outcome were noted. The highest heterogeneity of the virus population as measured by the number of single nucleotide polymorphisms and Shannon entropy was found in oropharyngeal swabs from quail, followed by turkeys and ducks. This suggests a strong bottleneck was imposed on the virus during replication in ducks, which can be explained by its poor adaptation and stronger selection pressure in waterfowl. The high within-host virus diversity in quail with high level of respiratory shedding and asymptomatic course of infection may contribute to our understanding of the role of quail as an intermediate host for adaptation of AIV to other species of poultry. In contrast, low virus complexity was observed in cloacal swabs, mainly from turkeys, showing that the within-host diversity may vary between different replication sites. Consequences of these observations on the virus evolution and adaptation require further investigation.
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Loesch, Charles R., Ronald E. Reynolds, and LeRoy T. Hansen. "An Assessment of Re-Directing Breeding Waterfowl Conservation Relative to Predictions of Climate Change." Journal of Fish and Wildlife Management 3, no. 1 (2012): 1–22. http://dx.doi.org/10.3996/032011-jfwm-020.
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Abstract The U.S. Fish and Wildlife Service has a long history of habitat conservation in the Prairie Pothole Region (PPR) of the United States that has focused on migratory birds, particularly waterfowl. The ongoing acquisition program of the U.S. Fish and Wildlife Service National Wildlife Refuge System has conserved approximately 1.1 million hectares of critical breeding waterfowl habitat. Results of recent predicted future climate scenarios are being used to suggest that waterfowl conservation be shifted away from currently important areas in the western and central portions of the U.S. PPR eastward, to locations where wetland and climate models suggest may become more conducive for providing wetland habitat for breeding ducks in the future. We used 24 years of breeding waterfowl and wetland monitoring data collected by the U.S. Fish and Wildlife Service National Wildlife Refuge System in the PPR of North and South Dakota and northeast Montana, along with land value and restoration cost data to conduct an economic assessment of the biological risk of refocusing waterfowl conservation efforts eastward due to recent projections of climate change. We considered the immediate risk of the loss of existing wetland and grassland resources in the western portion of the U.S. PPR, their current carrying capacity and production potential, the financial cost of protection vs. restoration relative to current conservation priorities, and the uncertainty of climate change effects on waterfowl habitat distribution. Because unprotected wetland and grassland habitats exist in the western and central portions of the PPR that are important for maintaining current waterfowl carrying capacity and productivity, and climate change effects are highly uncertain, maintaining the current focus of habitat protection appears to be the most cost effective approach for waterfowl habitat conservation efforts. Additionally, continued intensive monitoring activities designed to detect changing waterfowl populations and upland and wetland habitat as they relate to anthropogenic impacts (e.g., pattern tile drainage, grassland conversion) and climatic changes (e.g., wetland hydro-period), should provide more precise results to inform and adapt management and conservation activities accordingly should spatial and temporal changes in wet-dry cycles occur in the future.
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Beroud, T., J. Druais, Y. Bay, and J. C. Ricci. "Visual counts, bioacoustics and RADAR: three methods to study waterfowl prenuptial migration in Southern France." Animal Biodiversity and Conservation 35, no. 2 (2012): 175–88. http://dx.doi.org/10.32800/abc.2012.35.0175.
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This study comes from four years (2006–2009) of monitoring on two sites during the prenuptial migration. On each site, a monitoring of 24 hours per each 10–day period from the second 10–day period of January (J2), though February (F1–F3) and March (M1–M3), up to the first 10–day period of April (A1). Monitoring was carried out by RADAR (FURUNO FAR2127), associated with nocturnal bioacoustics recordings, and visual censuses on the same areas. The monitoring effort was considerable: visual counts carried out represent 282 counts–sites (n = 262,030 ducks counted), bioacoustics detected 9,573 calls during 814 hours of nocturnal recording and RADAR recorded 67,368 echoes on a set of 2,128 hours of monitoring. Visual counts showed a decline in the number of birds from late January/early February. Two patterns were observed with the nocturnal recordings with a maximum or a minimum of the value of bioacoustics index on F2 and F3, depending on the years. RADAR, the most relevant method for tracking of bird movements at a population level, identified two different abundance peaks using variables ‘flight altitude > 400 m’ and ‘flight direction towards north–east/south–east’, considered as characteritics of the prenuptial migration. The first peak was detected during F1 on Site 1 only in 2007 (once every four years) and during F2 on Site 2 only in 2006 (once every four years). A second peak with a higher number of echoes was recorded on M1 (Site 1) and on M2 (Site 2). Although all methods may suffer from different biases, the combination of two new technologies complementary to visual counts provided reliable and updated data for waterfowl migration in the Mediterranean area.
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Stanton, Philip B. "ESTABLISHING A BREEDING EIDER DUCK POPULATION IN MASSACHUSETTS." International Oil Spill Conference Proceedings 1989, no. 1 (1989): 493–95. http://dx.doi.org/10.7901/2169-3358-1989-1-493.
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ABSTRACT In an effort to make a waterfowl population with a limited breeding range—Maine to the Canadian Maritimes—less vulnerable to local catastrophe from petroleum activities, a population of common eiders (Somateria mollissima dressesi) was transplanted from Maine to Massachusetts. The objective of the relocation of the eiders was to see if a population of seabirds could successfully be moved from an area subject to petroleum activities to a new breeding ground. This move involved taking a group of birds from its existing breeding ground to a nonbreeding territory and establishing another breeding population. Such wildlife management techniques could contribute to increasing the reproductive potential of birds lost to oil spills, thus decreasing the need for high-cost oiled bird rehabilitation, which is often ecologically unsound. From 1973 to 1975, adult eiders and eggs were collected from Casco Bay, Maine. Eggs were hatched and hand-reared for several weeks both at the Wildlife Rehabilitation Center and on Penikese Island in Massachusetts. The birds were released on Penikese in Buzzard's Bay, about 240 kilometers (150 miles) south of their known breeding range, but in an area of habitat similar to that of the islands of Casco Bay. An acclimation program included rearing the birds at the release site for one to three weeks and introducing a saltwater environment and natural foods to the birds. The released eiders began breeding in 1976 on Penikese and have since colonized at least three nearby islands. By 1988 the population had increased to an estimated 200 breeding pairs.
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Norton, Michael R., and Vernon G. Thomas. "Economic Analyses of ‘Crippling Losses’ of North American Waterfowl and Their Policy Implications for Management." Environmental Conservation 21, no. 4 (1994): 347–53. http://dx.doi.org/10.1017/s037689290003366x.
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Hunter ‘crippling losses’, or unretrieved kill, probably range from 20% to 40% of all ducks hit by gunfire. However, this major mortality factor in duck populations has been largely ignored by waterfowl policymakers and managers. An economic analysis of ‘crippling losses’ for prairie Canada and the USA was conducted, based on 1992 harvest statistics. The analysis is based on current levels of spending on habitat programmes designed to bolster declining North American duck populations, with reference to the North American Waterfowl Management Plan.
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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 (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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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 (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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Drever, Mark C., Dominique Chabot, Patrick D. O'Hara, Jeffrey D. Thomas, André Breault, and Rhonda L. Millikin. "Evaluation of an unmanned rotorcraft to monitor wintering waterbirds and coastal habitats in British Columbia, Canada." Journal of Unmanned Vehicle Systems 3, no. 4 (2015): 256–67. http://dx.doi.org/10.1139/juvs-2015-0019.
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The effective protection of coastal and estuarine habitats requires reliable monitoring information on their use by waterbirds, and the use of small unmanned aircraft systems (UAS) may provide access to these habitats without disturbing birds. We evaluated the use of a rotary-wing UAS with a high-end consumer camera to identify and count wintering waterbirds at two coastal sites in British Columbia, Canada, in January 2015, and to map mudflat and marsh habitats. Photos of shorebirds, waterfowl, and seabird species were taken at varying altitudes, and disturbance of birds appeared minimal when the UAS was flown at heights ≥61 m. A ground resolution of ~1 cm/pixel was needed to discern plumage characteristics necessary to reliably identify birds. For some duck species, identification of females relied on body size or close association with a nearby male. Photographs were also used to derive accurate counts of shorebirds. For diving birds, accurate counts from photographs will require information on the proportion of birds on the water surface. Orthomosaics of coastal habitats were constructed with sufficient detail to assess ecological and geomorphological features. The UAS can therefore assist with bird species identification, population assessment, and characterization of habitat types.
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Shirkey, Brendan T., and Robert J. Gates. "Survival, Harvest, and Lincoln Estimates of Wood Ducks Banded in Ohio." Journal of Fish and Wildlife Management 11, no. 1 (2020): 185–95. http://dx.doi.org/10.3996/082019-jfwm-070.
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Abstract Wildlife agencies have carefully managed wood duck Aix sponsa populations in part through harvest regulations since the early 1900s. However, unlike many other waterfowl species in North America, waterfowl managers largely do not know breeding population size. Lincoln–Petersen methods based on harvest and band recovery data are an attractive alternative to air or ground count-based surveys for estimating populations of wood ducks by state and federal agencies that are tasked with sustainably managing harvest opportunities for this species. We used banding and recovery data to estimate annual survival rates, harvest rates, and population size in late summer (August–September) using Lincoln–Petersen methods for wood ducks banded within Ohio from 1990 to 2017. Sex, age, and daily bag limits best explained survival rates of wood ducks banded in Ohio, with lower survival rates in years with more liberal bag limits. Lincoln–Petersen estimates of population size ranged from 116,992 to 632,462 annually, and we detected a significant declining trend in population size through time. Mean harvest rates of wood ducks banded in Ohio ranged from 0.069 (adult females) to 0.121 (hatch-year males), and we detected a significant increasing trend in harvest rate through time for adult male, hatch-year male, and hatch-year female wood duck cohorts. Aerial surveys in other Great Lakes states provide comparable population estimates with our Lincoln–Petersen estimates for Ohio and also show a declining trend in population size. We recommend continued investigation into the use of Lincoln–Petersen techniques for estimating wood duck population size throughout the Great Lakes region. If declining population trends are not unique to Ohio, waterfowl managers may need to further assess the potential impact of increased harvest rates on population size to ensure sustainable harvest into the future.
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Andersson, Kent, Craig A. Davis, Grant Harris, and David A. Haukos. "Nonbreeding Duck Use at Central Flyway National Wildlife Refuges." Journal of Fish and Wildlife Management 9, no. 1 (2018): 45–64. http://dx.doi.org/10.3996/042017-jfwm-033.
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Abstract Within the U.S. portion of the Central Flyway, the U.S. Fish and Wildlife Service manages waterfowl on numerous individual units (i.e., Refuges) within the National Wildlife Refuge System. Presently, the extent of waterfowl use that Refuges receive and the contribution of Refuges to waterfowl populations (i.e., the proportion of the Central Flyway population registered at each Refuge) remain unassessed. Such an evaluation would help determine to what extent Refuges support waterfowl relative to stated targets, aid in identifying species requiring management attention, inform management targets, and improve fiscal efficiencies. Using historic monitoring data (1954–2008), we performed this assessment for 23 Refuges in Texas, New Mexico, Oklahoma, Kansas, and Nebraska during migration and wintering months (October–March). We examined six dabbling ducks and two diving ducks, plus all dabbling ducks and all diving ducks across two periods (long-term [all data] and short-term [last 10 October–March periods]). Individual Refuge use was represented by the sum of monthly duck count averages for October–March. We used two indices of Refuge contribution: peak contribution and January contribution. Peak contribution was the highest monthly count average for each October–March period divided by the indexed population total for the Central Flyway in the corresponding year; January contribution used the January count average divided by the corresponding population index. Generally, Refuges in Kansas, Nebraska, and New Mexico recorded most use and contribution for mallards Anas platyrhynchos. Refuges along the Texas Gulf Coast recorded most use and contribution for other dabbling ducks, with Laguna Atascosa and Aransas (including Matagorda Island) recording most use for diving ducks. The long-term total January contribution of the assessed Refuges to ducks wintering in the Central Flyway was greatest for green-winged teal Anas crecca with 35%; 12–15% for American wigeon Mareca americana, gadwall Mareca strepera, and northern pintail Anas acuta; and 7–8% for mallard and mottled duck Anas fulvigula. Results indicated that the reliance on the National Wildlife Refuge System decreased for these ducks, with evidence suggesting that, for several species, the assessed Refuges may be operating at carrying capacity. Future analyses could be more detailed and informative were Refuges to implement a single consistent survey methodology that incorporated estimations of detection bias in the survey process, while concomitantly recording habitat metrics on and neighboring each Refuge.
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Varner, Dana M., Aaron T. Pearse, Andrew A. Bishop, 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 (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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Zimmerman, Guthrie S., John R. Sauer, Kathy Fleming, William A. Link, and Pamela R. Garrettson. "Combining waterfowl and breeding bird survey data to estimate wood duck breeding population size in the Atlantic Flyway." Journal of Wildlife Management 79, no. 7 (2015): 1051–61. http://dx.doi.org/10.1002/jwmg.938.
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Wickson, RJ, FI Norman, GJ Bacher, and JS Garnham. "Concentrations of lead in bone and other tissues of Victorian waterfowl." Wildlife Research 19, no. 2 (1992): 221. http://dx.doi.org/10.1071/wr9920221.
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The concentrations of lead in wing bones of Victorian waterfowl were determined from samples collected mainly during the opening weekend of the 1990 duck-hunting season. Of about 7000 wings collected, 1134 (of 12 species and from wetland collection sites throughout the State) were subsampled for analysis. Although lead concentrations in bone were low in some species (e.g. chestnut and grey teal, freckled duck), higher concentrations were found in some small samples of diving ducks and in Pacific black duck. Tissues of Pacific black duck from one major hunting area indicated exposure to lead. Of 194 gizzards inspected, 28 (14.4%) contained ingested and eroded lead shotgun pellets. Lead concentrations in the livers of some Pacific black duck were also elevated, with 4.6% having more than 2.0mg kg-1. Other studies have found that waterfowl may die after ingestion of lead shotgun pellets; since such pellets may present a similar threat to local waterfowl populations, the use of alternative non-toxic ammunition should be encouraged.
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Leacy, Alexander, Éva Nagy, Phuc H. Pham, and Leonardo Susta. "In Vitro and In Ovo Host Restriction of Aquatic Bird Bornavirus 1 in Different Avian Hosts." Viruses 12, no. 11 (2020): 1272. http://dx.doi.org/10.3390/v12111272.
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Aquatic bird bornavirus 1 (ABBV-1) is associated with chronic meningoencephalitis and ganglioneuritis. Although waterfowl species act as the natural host of ABBV-1, the virus has been sporadically isolated from other avian species, showing the potential for a broad host range. To evaluate the host restriction of ABBV-1, and its potential to infect commercial poultry species, we assessed the ability of ABBV-1 to replicate in cells and embryos of different avian species. ABBV-1 replication was measured using multi- and single-step growth curves in primary embryo fibroblasts of chicken, duck, and goose. Embryonated chicken and duck eggs were infected through either the yolk sac or chorioallantoic cavity, and virus replication was assessed by immunohistochemistry and RT-qPCR in embryonic tissues harvested at two time points after infection. Multi-step growth curves showed that ABBV-1 replicated and spread in goose and duck embryo fibroblasts, establishing a population of persistently infected cells, while it was unable to do so in chicken fibroblasts. Single-step growth curves showed that cells from all three species could be infected; however, persistence was only established in goose and duck fibroblasts. In ovo inoculation yielded no detectable viral replication or lesion in tissues. Data indicate that although chicken, duck, and goose embryo fibroblasts can be infected with ABBV-1, a persistent infection is more easily established in duck and goose cells. Therefore, ABBV-1 may be able to infect chickens in vivo, albeit inefficiently. Additionally, our data indicate that an in ovo model is inadequate to investigating ABBV-1 host restriction and pathogenesis.
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Achenbach, Jenna E., and Richard A. Bowen. "Effect of Oseltamivir Carboxylate Consumption on Emergence of Drug-Resistant H5N2 Avian Influenza Virus in Mallard Ducks." Antimicrobial Agents and Chemotherapy 57, no. 5 (2013): 2171–81. http://dx.doi.org/10.1128/aac.02126-12.
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ABSTRACTOseltamivir carboxylate (OC) has been detected in environmental waters at various levels during recent influenza seasons in humans, reflecting levels of usage and stability of this drug. In consideration of the role of waterfowl as hosts for influenza viruses that may contribute to human infections, we evaluated the effect of consumption of low doses of OC on development of oseltamivir-resistant influenza virus mutants in mallard ducks (Anas platyrhynchos) infected with two different low-pathogenic (LP) H5N2 avian influenza viruses (AIV). We detected development of virus variants carrying a known molecular marker of oseltamivir resistance (neuraminidase E119V) in 4 out of 6 mallards infected with A/Mallard/Minnesota/182742/1998 (H5N2) and exposed to 1,000 ng/liter OC. The mutation first appeared as a minor population on days 5 to 6 and was the dominant genotype on days 6 to 8. Oseltamivir-resistant mutations were not detected in virus from ducks not exposed to the drug or in ducks infected with a second strain of virus and similarly exposed to OC. Virus isolates carrying the E119V mutation displayedin vitroreplication kinetics similar to those of the wild-type virus, butin vivo, the E119V virus rapidly reverted back to wild type in the absence of OC, and only the wild-type parental strain was transmitted to contact ducks. These results indicate that consumption by wild waterfowl of OC in drinking water may promote selection of the E119V resistance mutation in some strains of H5N2 AIV that could contribute to viruses infecting human populations.
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Lovas-Kiss, Ádám, Orsolya Vincze, Viktor Löki, et al. "Experimental evidence of dispersal of invasive cyprinid eggs inside migratory waterfowl." Proceedings of the National Academy of Sciences 117, no. 27 (2020): 15397–99. http://dx.doi.org/10.1073/pnas.2004805117.
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Fish have somehow colonized isolated water bodies all over the world without human assistance. It has long been speculated that these colonization events are assisted by waterbirds, transporting fish eggs attached to their feet and feathers, yet empirical support for this is lacking. Recently, it was suggested that endozoochory (i.e., internal transport within the gut) might play a more important role, but only highly resistant diapause eggs of killifish have been found to survive passage through waterbird guts. Here, we performed a controlled feeding experiment, where developing eggs of two cosmopolitan, invasive cyprinids (common carp, Prussian carp) were fed to captive mallards. Live embryos of both species were retrieved from fresh feces and survived beyond hatching. Our study identifies an overlooked dispersal mechanism in fish, providing evidence for bird-mediated dispersal ability of soft-membraned eggs undergoing active development. Only 0.2% of ingested eggs survived gut passage, yet, given the abundance, diet, and movements of ducks in nature, our results have major implications for biodiversity conservation and invasion dynamics in freshwater ecosystems.
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Spackman, Erica, David E. Swayne, David L. Suarez, et al. "Characterization of Low-Pathogenicity H5N1 Avian Influenza Viruses from North America." Journal of Virology 81, no. 21 (2007): 11612–19. http://dx.doi.org/10.1128/jvi.01368-07.
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ABSTRACT Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 105.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage.
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Gulyaeva, Marina, Maria Alessandra De Marco, Ganna Kovalenko, et al. "Biological Properties and Genetic Characterization of Novel Low Pathogenic H7N3 Avian Influenza Viruses Isolated from Mallard Ducks in the Caspian Region, Dagestan, Russia." Microorganisms 9, no. 4 (2021): 864. http://dx.doi.org/10.3390/microorganisms9040864.
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Avian influenza viruses (AIVs) are maintained in wild bird reservoirs, particularly in mallard ducks and other waterfowl. Novel evolutionary lineages of AIV that arise through genetic drift or reassortment can spread with wild bird migrations to new regions, infect a wide variety of resident bird species, and spillover to domestic poultry. The vast continental reservoir of AIVs in Eurasia harbors a wide diversity of influenza subtypes, including both highly pathogenic (HP) and low pathogenic (LP) H7 AIV. The Caspian Sea region is positioned at the intersection of major migratory flyways connecting Central Asia, Europe, the Black and Mediterranean Sea regions and Africa and holds a rich wetland and avian ecology. To understand genetic reservoirs present in the Caspian Sea region, we collected 559 cloacal swabs from Anseriformes and other species during the annual autumn migration periods in 2017 and 2018. We isolated two novel H7N3 LPAIV from mallard ducks whose H7 hemagglutinin (HA) gene was phylogenetically related to contemporaneous strains from distant Mongolia, and more closely Georgia and Ukraine, and predated the spread of this H7 LPAIV sublineage into East Asia in 2019. The N3 neuraminidase gene and internal genes were prototypical of AIV widely dispersed in wild bird reservoirs sampled along flyways connected to the Caspian region. The polymerase and nucleoprotein segments clustered with contemporaneous H5 HPAI (clade 2.3.4.4b) isolates, suggesting the wide dispersal of H7 LPAIV and the potential of this subtype for reassortment. These findings highlight the need for deeper surveillance of AIV in wild birds to better understand the extent of infection spread and evolution along spatial and temporal flyways in Eurasia.
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Arnold, Todd W., and Erik K. Fritzell. "Habitat use by male mink in relation to wetland characteristics and avian prey abundances." Canadian Journal of Zoology 68, no. 10 (1990): 2205–8. http://dx.doi.org/10.1139/z90-306.
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We documented use of wetland habitats by five radio-marked male mink (Mustela vison) in the aspen parklands of southwestern Manitoba during May–July of 1984 and 1985. Mink activity was most frequent on large, well-flooded, semipermanent and permanent wetlands with irregular shorelines and large areas of open water. These variables were also positively correlated with abundances of waterfowl and other birds. Habitat variables explained 26% of the variation in wetland use by male mink. Grebes, coots, and diving ducks had high habitat overlap with mink, whereas dabbling ducks and blackbirds overlapped little with mink. Bird abundances explained nearly as much variation in habitat use by mink as did physical habitat variables (R2 = 0.24), but some of this association may have been due to selection for (or avoidance of) similar habitats. Combined analysis with habitat and avifaunal variables explained 31% of the variation in wetland use by male mink. Patterns of habitat use by mink and avian prey may help explain previously documented trends of prey selection among prairie mink.
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Kulikova, I. V., Y. N. Zhuravlev, I. G. Korobitsyn, G. A. Nemkova, K. G. McCracken, and J. L. Peters. "Holarctic phylogeographic structure of Eurasian wigeon (Mareca penelope)." Vavilov Journal of Genetics and Breeding 23, no. 3 (2019): 362–69. http://dx.doi.org/10.18699/vj19.503.
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The Eurasian wigeon (Mareca penelope) is one of the most numerous migrant species of waterfowl in the Palearctic. Annually, significant part of the world’s wigeon population makes seasonal flights over distances from tens to thousands or more kilometers. According to different estimates based on banding data, five geographic populations of the species were described in the Palearctic. However, distinct borders between the populations have not been identified. At the same time, no phylogeographic studies have been carried out for the complete native range of wigeon so far. In addition to the fundamental importance of such a study, knowledge of the genetic structure of populations is necessary for the development of measures to increase the number of and preserve this valuable game species. The aim of our work was a phylogeographic analysis of the wigeon across its vast native range in the Palearctic including ducks wintering in North America. We examined genetic diversity and differentiation of wigeon populations identified with banding data, phylogenetic relationships of mtDNA haplotypes and demographic history of populations and species as a whole by sequencing a 661 base-pair 5’-fragment of the mitochondrial control region from 195 individual ducks collected throughout the Palearctic and Nearctic. Genetic diversity was high in all studied populations. A reconstruction of haplotypes phylogeny revealed the absence of geographic structure in the data. Nonetheless, analysis of molecular variance (AMOVA) identified two groups of populations: EuropeanSiberian and East Asian. The former included wigeons from Europe, Siberia and the Atlantic coast of North America, and the latter comprised ducks from Russian Far East, Kamchatka Peninsula, Chukotka Autonomous District, the Aleutian Islands, Alaska, and the Pacific coast of North America.
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Circella, Elena, Antonio Camarda, Luca Bano, et al. "Botulism in Wild Birds and Changes in Environmental Habitat: A Relationship to be Considered." Animals 9, no. 12 (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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Negovetich, Nicholas J., and Robert G. Webster. "Thermostability of Subpopulations of H2N3 Influenza Virus Isolates from Mallard Ducks." Journal of Virology 84, no. 18 (2010): 9369–76. http://dx.doi.org/10.1128/jvi.01170-10.
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ABSTRACT Maintenance of avian influenza virus in waterfowl populations requires that virions remain infectious while in the environment. Temperature has been shown to negatively correlate with persistence time, which is the duration for which virions are infectious. However, thermostability can vary between isolates regardless of subtype, and it is not known whether this variation occurs when host and geographic location of isolation are controlled. In this study, we analyzed the thermostabilities of 7 H2N3 viruses isolated from mallard ducks in Alberta, Canada. Virus samples were incubated at 37°C and 55°C, and infectivity titers were calculated at different time points. Based on the rate of infectivity inactivation at 37°C, isolates could be grouped into either a thermosensitive or thermostable fraction for both egg- and MDCK-grown virus populations. Titers decreased more rapidly for isolates incubated at 55°C, and this loss of infectivity occurred in a nonlinear, 2-step process, which is in contrast with the consensus on thermostability. This suggests that stock samples contain a mixture of subpopulations with different thermostabilities. The rate of decrease for the sensitive fraction was approximately 14 times higher than that for the stable fraction. The presence of subpopulations is further supported by selection experiments and plaque purification, both of which result in homogenous populations that exhibit linear decreases of infectivity titer. Therefore, variation of thermostability of influenza virus isolates begins at the level of the population. The presence of subpopulations with high thermostability suggests that avian viruses can persist in water longer than previously estimated, thus increasing the probability of transmission to susceptible hosts.
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Golden, Glen J., Meredith J. Grady, Hailey E. McLean, et al. "Biodetection of a specific odor signature in mallard feces associated with infection by low pathogenic avian influenza A virus." PLOS ONE 16, no. 5 (2021): e0251841. http://dx.doi.org/10.1371/journal.pone.0251841.
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Outbreaks of avian influenza virus (AIV) infection included the spread of highly pathogenic AIV in commercial poultry and backyard flocks in the spring of 2015. This resulted in estimated losses of more than $8.5 million from federal government expenditures, $1.6 billion from direct losses to produces arising from destroyed turkey and chicken egg production, and economy-wide indirect costs of $3.3 billion from impacts on retailers and the food service industries. Additionally, these outbreaks resulted in the death or depopulation of nearly 50 million domestic birds. Domesticated male ferrets (Mustela putorius furo) were trained to display a specific conditioned behavior (i.e. active scratch alert) in response to feces from AIV-infected mallards in comparison to feces from healthy ducks. In order to establish that ferrets were identifying samples based on odors associated with infection, additional experiments controlled for potentially confounding effects, such as: individual duck identity, housing and feed, inoculation concentration, and day of sample collection (post-infection). A final experiment revealed that trained ferrets could detect AIV infection status even in the presence of samples from mallards inoculated with Newcastle disease virus or infectious laryngotracheitis virus. These results indicate that mammalian biodetectors are capable of discriminating the specific odors emitted from the feces of non-infected versus AIV infected mallards, suggesting that the health status of waterfowl can be evaluated non-invasively for AIV infection via monitoring of volatile fecal metabolites. Furthermore, in situ monitoring using trained biodetectors may be an effective tool for assessing population health.
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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 (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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Williams, Christen L., Richard C. Brust, and Olin E. Rhodes Jr. "Microsatellite Polymorphism and Genetic Structure of Florida Mottled Duck Populations." Condor 104, no. 2 (2002): 424–31. http://dx.doi.org/10.1093/condor/104.2.424.
Full textAbstract:
Abstract Little is understood concerning the effects regional isolation and habitat loss have had upon the genetic structure of Mottled Ducks (Anas fulvigula), a nonmigratory waterfowl species with a limited distribution. Our objective was to identify nuclear DNA-based markers for Mottled Ducks and determine levels of subdivision among populations in Florida. We screened 13 microsatellite primer pairs and identified six microsatellite loci that were variable in Mottled Ducks. These markers revealed a low level of genetic differentiation and a high level of genetic exchange among four Mottled Duck subpopulations within Florida. Over all populations, single-locus expected heterozygosities over the six loci surveyed ranged from 0.13–0.85. There were no significant differences in gene frequencies among the populations examined, and the Fst over 5 biparental loci was not different from zero. Our analysis of the Florida Mottled Duck population indicated high levels of heterozygosity and no evidence of genetic subdivision among breeding units. Polimorfismo en Microsatélites y Estructura Genética en Poblaciones de Anas fulvigula Resumen. Se tiene escaso conocimiento acerca de los efectos del aislamiento regional y de la pérdida de hábitat sobre la estructura genética de poblaciones de Anas fulvigula, un ave acuática no migratoria de distribución restringida. Nuestro objetivo fue identificar marcadores genéticos de ADN para A. fulvigula y determinar los niveles de subdivisión entre poblaciones en Florida. Examinamos 13 pares de iniciadores (i.e., primers) para microsatélites e identificamos seis loci que fueron variables en A. fulvigula. Estos marcadores revelaron un bajo nivel de diferenciación genética y un alto grado de intercambio genético entre cuatro subpoblaciones de A. fulvigula en Florida. Para todas las poblaciones, la heterocigocidad esperada en un locus varió entre 0.13–0.85 para los seis loci examinados. No hubo diferencias significativas en las frecuencias génicas entre las subpoblaciones examinadas, y el valor de Fst para los 5 loci biparentales no fue diferente de cero. Nuestros análisis de las poblaciones de A. fulvigula de Florida indicaron altos niveles de heterocigocidad y no mostraron evidencia de subdivisión genética entre las unidades reproductivas.
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Bentzen, Rebecca, Joe Liebezeit, Martin Robards, Bill Streever, Samantha Strindberg, and Steve Zack. "Bird Use of Northern Alaska Oilfield Rehabilitation Sites." ARCTIC 71, no. 4 (2018): 422–30. http://dx.doi.org/10.14430/arctic4747.
Full textAbstract:
Breeding bird response to habitat rehabilitation after anthropogenic disturbance has received little attention in the Arctic. The North Slope of Alaska is an important breeding ground for many populations of migratory birds and has also supported major oilfields since the late 1960s. The most obvious impacts of industrial development to nesting birds are direct habitat loss and fragmentation resulting from the construction of infrastructure, along with increased mechanical noise, vehicle traffic, and other forms of anthropogenic disturbance. In response to state and federal requirements, efforts have been made to rehabilitate abandoned portions of the oilfields. We compared bird use at rehabilitation sites and at nearby paired reference sites. Densities of shorebirds and passerines varied between rehabilitation sites and reference sites, but waterfowl densities did not. Specifically, passerine and shorebird densities were higher at reference sites in the early or mid-season and lower at reference sites in the late season. Additionally, birds on rehabilitation sites were primarily observed foraging and resting, while behavior observed on paired reference sites was more diverse and included courtship displays, nesting, and aggression. Further, rehabilitation sites supported significantly fewer nests and fewer species than recorded at reference sites. Our findings suggest that sites 3 to 10 years post rehabilitation do not provide bird habitat comparable to nearby reference sites and, by extension, do not provide shorebird and passerine habitat comparable to that found prior to development. However, rehabilitation sites appear to provide adequate habitat for waterfowl and are important to shorebirds and passerines as foraging areas. Continued monitoring will be needed to establish the long-term suitability of rehabilitation sites, compared to reference sites, as breeding habitat for birds.
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Benoy, Glenn A. "Variation in tiger salamander density within prairie potholes affects aquatic bird foraging behaviour." Canadian Journal of Zoology 83, no. 7 (2005): 926–34. http://dx.doi.org/10.1139/z05-081.
Full textAbstract:
Through competitive asymmetry, coexisting fish populations can alter aquatic bird distributions and reduce the reproductive success of their offspring. Gray tiger salamanders (Ambystoma mavortium diaboli Dunn, 1940) may function similarly in fishless prairie potholes. To test the hypothesis that tiger salamanders compete with aquatic birds (including ducks, grebes, and American Coot (Fulica americana J.F. Gmelin, 1789)) for prey resources during the breeding season, 16 potholes were divided into halves by an impermeable plastic barrier and tiger salamander densities were increased or decreased on opposite sides of the barrier. From late May until early July, aquatic invertebrates were sampled from both sides of the divider and the foraging activities of birds were observed. Invertebrate samples revealed that densities of most macroinvertebrate taxa were lower in the halves of potholes with relatively higher densities of tiger salamanders. On average, bird occupancy was evenly distributed on either side of the divider. In contrast, birds spent 65% more time foraging where tiger salamander densities were low (71.2% of total time observed) than where they were high (46.2% of total time observed). The birds most responsive to differences in tiger salamander density and food availability were dabbling ducks, followed by American Coot and diving ducks. This ranking corresponds to the degree of dietary overlap documented between tiger salamanders and aquatic bird assemblages in the study area.
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Pacha, R. E., G. W. Clark, E. A. Williams, and A. M. Carter. "Migratory birds of central Washington as reservoirs of Campylobacter jejuni." Canadian Journal of Microbiology 34, no. 1 (1988): 80–82. http://dx.doi.org/10.1139/m88-015.
Full textAbstract:
Migratory ducks, Canada geese, and sandhill crane from the Pacific North American Flyway have been screened for Campylobacter spp. Samples (298) from these birds were examined and the incidence of Campylobacter spp. in the samples were as follows: sandhill crane (Grus canadensis tabida), 81 %; ducks (Aythya collaris, Anas carolinensis, Aythya americana, and Anas platyrhynchos), 73%; and Canada geese (Branta canadensis), 5%. All isolates were identified as Campylobacter jejuni. To our knowledge this is the first report of the isolation of C. jejuni from sandhill crane. The high frequency of isolation in both the sandhill crane and migratory ducks indicated that these bird populations may play a significant role in the dissemination of the bacterium. Because of their migratory habits, these birds may be particularly important in spreading C. jejuni to remote areas.
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Rattner, Barnett A., G. Michael Haramis, Diane S. Chu, Christine M. Bunck, and Colin G. Scanes. "Growth and physiological condition of black ducks reared on acidified wetlands." Canadian Journal of Zoology 65, no. 12 (1987): 2953–58. http://dx.doi.org/10.1139/z87-448.
Full textAbstract:
Acid deposition has been identified as one of several possible factors contributing to the decline of some waterfowl populations in North America. In an effort to examine the effects of acidification on black duck (Anas rubripes) recruitment, growth and physiological condition were monitored in ducklings foraging for a 10–day trial (days 10–20 of life) on acidified (pH 5.0) and circumneutral (pH 6.8) fish-free emergent wetlands. Acidification of these wetlands suppressed phytoplankton and algal growth, and reduced invertebrate biomass. Ducklings maintained on acidified wetlands grew poorly compared with ducklings reared on circumneutral wetlands, as evidenced by lower final body weight and culmen and tarsus length. Plasma growth hormone concentration was elevated and triiodothyronine levels were lower in stunted ducklings, in part substantiating impairment of growth-regulating processes. Ducklings exhibiting poor growth tended to have lower hematocrit, lower plasma protein, glucose, and cholesterol concentrations, and higher uric acid levels, presumably reflecting alterations in metabolism and development due to inanition. These findings suggest that acid deposition may lower food production in wetlands and ultimately impair duckling growth, condition, and survival.
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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 (2017): 434–43. http://dx.doi.org/10.4039/tce.2017.16.
Full textAbstract:
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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Robertson, Gregory J., Molly Tomlik, G. Randy Milton, Glen J. Parsons, and Mark L. Mallory. "Increases in the Number of American Black Ducks Wintering in Nova Scotia, 1970–2015." Journal of Fish and Wildlife Management 8, no. 2 (2017): 669–75. http://dx.doi.org/10.3996/032017-jfwm-031.
Full textAbstract:
Abstract Despite extensive conservation and management efforts, American black duck (Anas rubripes) populations remain below desired population levels. Researchers have noted declines at a number of wintering areas, but indications are that wintering populations in the northern part of the range are increasing. Intermittently between 1970 and 1989, and annually since 1992, wildlife biologists have flown aerial surveys of the entire coast of Nova Scotia, Canada, to count wintering waterfowl. This survey counted the total number of ducks seen in predefined lengths of coastline. We analyzed those survey data using generalized linear mixed models, over the entire time period (1970–2015) and in the recent time period (1992–2015, when surveys were done every year), across five general regions of Nova Scotia. We fit models using Bayesian methods with uninformative priors; models with negative binomial response distributions performed well. Due to the large variation in mean numbers of black ducks across the predefined lengths of coastline, we treated these blocks of coastline as a fixed effect, while annual trend (slope) was modeled as a random effect to account for variation in annual trend across blocks of coastline. Results were similar between the entire time series (1970–2015) or the most recent and more complete time series (1992–2015). In general, numbers of wintering black ducks in Nova Scotia increased (1.0–16.0%/y) and increases were significant (Bayesian credible intervals did not bound 0) in four of five regions. Increasing numbers in Nova Scotia are consistent with other observations of increasing wintering numbers at the northern range of American black ducks and may indicate a shift in the wintering range that has been ongoing for decades. Future habitat management actions will benefit from consideration of regional trends and the distributional change of black duck.
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Davganyam, Bayarmagnai, Nyamsuren Otgontogtokh, Baljidmaa Batmunkh, et al. "Avian influenza surveillance in wild birds using sentinel ducks." Mongolian Journal of Agricultural Sciences 29, no. 1 (2020): 3–8. http://dx.doi.org/10.5564/mjas.v29i1.1317.
Full textAbstract:
We conducted active surveillance for avian influenza virus using sentinel ducks in central region of Mongolia (Khunt lake Saikhan soum, Bulgan province) that major wild bird habitat and outbreak site of H5N1 HPAI in wild birds in Mongolia from 2005 to 2011. Total of 39/104 (37,5%) samples were positive by insulated isothermal PCR (iiPCR) and 42/104 (40,38%) swab samples were positive by real time PCR (qPCR). In addition, AIV antibody detected in 35/104 (33,65%) serum samples tested by AIV NP ELISA kit. These results indicated that sentinel surveillance using domestic birds could be an effective method for avian pathogens including influenza in Mongolia. Enhanced sentinel surveillance in wild bird populations in Mongolia is therefore crucial for the understanding of global AIV transmission and epidemiology.
 Шувууны томуугийн тандах судалгаанд туршуул шувуу (Sentinel bird) байршуулах арга ашигласан дүнгээс
 Бид шувууны томуугийн тандах судалгаанд туршуул шувуу байршуулах арга зүйг ашиглах боломжийг судлах зорилгоор урьдчилсан туршилтыг 2019 оны 7-10 сард Булган аймгийн Сайхан сумын Хунт нууранд хийж гүйцэтгэв. Хунт нуур нь олон тооны нүүдлийн усны шувууд зусах болон дайрч өнгөрдөг ач холбогдолтой цэг бөгөөд 2005-2011 онд өндөр хоруу чанартай шувууны томуугийн (HPAI) A/H5N1 дэд хэвшлийн вирус илэрч байсан. Шувуунаас авсан арчдасны зарим дээжийг insulated isothermal PCR (iiPCR)-р шинжлэхэд 39/104 (37,5%), дээж эерэг, бүх дээжийг PCR (qPCR)-р шинжлэхэд 42/104 (40,38%) нь дээж эерэг дүн үзүүлсэн. Харин ийлдсэнд шувууны томуугийн эсрэг бием илрүүлэх ELISA-ийн шинжилгээгээр 35/104 (33,65%) дээжинд эсрэг бием илэрсэн. Иймд энэ арга зүйг Монгол орны нөхцөлд тохируулан сайжруулж шувууны томуугийн үүсгэгчийг илрүүлэхэд ашиглах нь уг өвчний эпидемиологийн байдлыг танин мэдэхэд чухал ач холбогдолтой юм.
 Түлхүүр үг: нугас, вирус, дархлаа, эпидемиологи, тархалт, ПГУ (Полимеразан гинжин урвал)
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Pasitschniak-Arts, Maria, and François Messier. "Predator identification at simulated waterfowl nests using inconspicuous hair catchers and wax-filled eggs." Canadian Journal of Zoology 73, no. 5 (1995): 984–90. http://dx.doi.org/10.1139/z95-115.
Full textAbstract:
We tested the efficiency of thin, inconspicuous wire hair catchers and wax-filled eggs to differentiate between mammalian and avian predators of upland nesting ducks. In contrast to a previously tested hair catcher (lacerated metal sheeting, modified bridge-stake design), our hair catcher was designed to be unobtrusive, to avoid attracting predators to nests. In total, 578 simulated nests (78 with metal sheeting and 500 with inconspicuous wire hair catchers) were set up in Thickwood Hills, Saskatchewan. Each nest contained seven fresh chicken eggs and two wax-filled eggs for collecting tooth and beak marks of predators. Predation by mammals and birds accounted for 30 and 70% of depredated nests (n = 78) with metal-sheeting hair catchers compared with 76.5 and 23.5% (n = 143) of nests with inconspicuous wire hair catchers, respectively; metal-sheeting hair catchers created a severe bias toward bird predation. Restricting our analysis to nests with inconspicuous wire hair catchers, hair and feather samples were obtained at 45.1 and 2.2% of depredated nests (n = 317), respectively. Another 30.3% of depredated nests contained marked wax-filled eggs, of which 75% related to mammalian predation and 25% to avian predation. Overall, we could differentiate between mammalian and avian predation in 77.6% of destroyed nests. Based on hair samples, the striped skunk (Mephitis mephitis) was the dominant predator (75% occurrence) among mammalian species.
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Wu, Tong, and Charles Perrings. "Conservation, development and the management of infectious disease: avian influenza in China, 2004–2012." Philosophical Transactions of the Royal Society B: Biological Sciences 372, no. 1722 (2017): 20160126. http://dx.doi.org/10.1098/rstb.2016.0126.
Full textAbstract:
There is growing evidence that wildlife conservation measures have mixed effects on the emergence and spread of zoonotic disease. Wildlife conservation has been found to have both positive (dilution) and negative (contagion) effects. In the case of avian influenza H5N1 in China, the focus has been on negative effects. Lakes and wetlands attracting migrating waterfowl have been argued to be disease hotspots. We consider the implications of waterfowl conservation for H5N1 infections in both poultry and humans between 2004 and 2012. We model both environmental and economic risk factors. Environmental risk factors comprise the conditions that structure interaction between wild and domesticated birds. Economic risk factors comprise the cost of disease, biosecurity measures and disease risk mitigation. We find that H5N1 outbreaks in poultry populations are indeed sensitive to the existence of wild-domesticated bird mixing zones, but not in the way we would expect from the literature. We find that risk is decreasing in protected migratory bird habitat. Since the number of human cases is increasing in the number of poultry outbreaks, as expected, the implication is that the protection of wetlands important for migratory birds offers unexpected human health benefits. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’.
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Rodway, Michael S. "Activity patterns, diet, and feeding efficiency of Harlequin Ducks breeding in northern Labrador." Canadian Journal of Zoology 76, no. 5 (1998): 902–9. http://dx.doi.org/10.1139/z98-019.
Full textAbstract:
The lack of data on summer diet and feeding behaviour for the endangered eastern North American population of Harlequin Ducks (Histrionicus histrionicus) prompted a study of activity patterns and feeding ecology in a coastal stream in Hebron Fiord, Labrador. Diurnal activity patterns varied by habitat and changed through the season. Extensive feeding occurred in slow-moving waters, contrary to expectation. Females spent 40% of daylight hours feeding during the prelaying period, more than twice the time spent by males and higher than that reported in other studies. Diurnal feeding patterns showed little variation in the prelaying period and major peaks of activity in the morning and evening during incubation and brood rearing. Larval Simuliidae (Diptera) were absent from a fecal sample taken in July but dominated the prey remains in feces collected in August. Dive times averaged 10-24 s and varied with depth of water. Dive-pause ratios of 1.7-2.2 were lower than previously reported. The results support the hypothesis that populations are food-limited on the breeding grounds, and suggest that there may be greater energy constraints on foraging effort in river specialists than in dabbling or other diving waterfowl.
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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 (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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Mallory, Mark L. "Reactions of ground-nesting marine birds to human disturbance in the Canadian Arctic." Arctic Science 2, no. 2 (2016): 67–77. http://dx.doi.org/10.1139/as-2015-0029.
Full textAbstract:
I studied the reactions of five ground-nesting marine bird species (Arctic tern (Sterna paradisaea), Sabine’s gull (Xema sabini), common eider (Somateria mollissima), long-tailed duck (Clangula hyemalis), and Ross’ gull (Rhodostethia rosea)) breeding in the low and high Arctic to disturbance from nearby aircraft as well as avian flight initiation response to humans approaching on foot. All species except nesting long-tailed ducks and common eiders departed their nest when overhead aircraft were within 200 m, with loafing birds often flying off when aircraft were still 1 km away. There was considerable individual and species-specific variation in responses to approaching humans, with some nesting birds not flushing from their nest until touched by a researcher (e.g., waterfowl, 0 m), while others flushed when people were 400 m away (Ross’s gull). Excluding Ross’s gulls, 95% of the individuals of most species did not initiate flight until humans were ≤100 m from the nest, suggesting that this might represent a minimum, suitable “buffer zone” around nesting colonies for nonmotorized human activities.