Um die anderen Arten von Veröffentlichungen zu diesem Thema anzuzeigen, folgen Sie diesem Link: Mallard.

Zeitschriftenartikel zum Thema „Mallard“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an

Wählen Sie eine Art der Quelle aus:

Machen Sie sich mit Top-50 Zeitschriftenartikel für die Forschung zum Thema "Mallard" bekannt.

Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.

Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.

Sehen Sie die Zeitschriftenartikel für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.

1

Williams, Murray. "Can grey duck (Anas superciliosa) x mallard (A. platyrhynchos) hybrids be recognised in the field?" Notornis 66, no. 2 (2019): 45. https://doi.org/10.63172/542971bndfjk.

Der volle Inhalt der Quelle
Annotation:
Face, wing, bill, and leg characteristics of grey ducks (Anas. s. superciliosa), of captive-raised F1 and backcrossed grey duck x mallard (A. platyrhynchos) hybrids, and of wild “grey-like” and “mallard-like” ducks in New Zealand were evaluated to assist recognition of grey duck x mallard hybrids in the field. Face pattern was the single character best able to discriminate grey ducks from all others, most grey-like hybrids from all mallard-like hybrids, but not most F1 and backcrossed mallard hybrids from mallards. Upper wing pattern, and bill and leg colours assisted discrimination alongside
APA, Harvard, Vancouver, ISO und andere Zitierweisen
2

Gillespie, Grant D. "Hybridization, Introgression, and Morphometric Differentiation between Mallard (Anas platyrhynchos) and Grey Duck (Anas superciliosa) in Otago, New Zealand." Auk 102, no. 3 (1985): 459–69. http://dx.doi.org/10.1093/auk/102.3.459.

Der volle Inhalt der Quelle
Annotation:
Abstract Small numbers of Mallard (Anas platyrhynchos) were introduced into New Zealand from Great Britain and North America over 100 years ago. Both sexes have undergone differentiation in size and plumage characters as a consequence of hybridization with the indigenous Grey Duck (A. superciliosa). Pure forms of both species, as documented by early descriptions, appear to be disappearing, particularly the Grey Duck. In Otago, the Mallard and Grey Duck are introgressively hybridizing, and the majority of intergrades are Mallard-like in appearance. Separation of Mallards, hybrid birds, and Grey
APA, Harvard, Vancouver, ISO und andere Zitierweisen
3

Schummer, Michael L., John Simpson, Brendan Shirkey, Samuel R. Kucia, Philip Lavretsky, and Douglas C. Tozer. "Population genetics and geographic origins of mallards harvested in northwestern Ohio." PLOS ONE 18, no. 3 (2023): e0282874. http://dx.doi.org/10.1371/journal.pone.0282874.

Der volle Inhalt der Quelle
Annotation:
The genetic composition of mallards in eastern North America has been changed by release of domestically-raised, game-farm mallards to supplement wild populations for hunting. We sampled 296 hatch-year mallards harvested in northwestern Ohio, October–December 2019. The aim was to determine their genetic ancestry and geographic origin to understand the geographic extent of game-farm mallard introgression into wild populations in more westward regions of North America. We used molecular analysis to detect that 35% of samples were pure wild mallard, 12% were early generation hybrids between wild
APA, Harvard, Vancouver, ISO und andere Zitierweisen
4

Tracey, John P., Brian S. Lukins, and Chris Haselden. "Hybridisation between mallard (Anas platyrhynchos) and grey duck (A. superciliosa) on Lord Howe Island and management options." Notornis 55, no. 1 (2008): 1. https://doi.org/10.63172/392783csrpjp.

Der volle Inhalt der Quelle
Annotation:
Introduced mallards (Anas platyrhynchos) occur on many islands of the South Pacific, where they hybridise with the resident grey duck (A. superciliosa). In October 2007, we conducted systematic surveys of Lord Howe Island to estimate the abundance and distribution of grey ducks, mallards, and their hybrids. Hybrids were common in areas of high public use, particularly where there was mown or grazed grass. Phenotypic characteristics suggest that mallards are now dominant and have supplanted the native grey duck, with 81% of birds classified as mallard or mallard-like hybrids, 17% as intermediat
APA, Harvard, Vancouver, ISO und andere Zitierweisen
5

Williams, Murray. "The changing relative abundance of grey duck (Anas superciliosa) and mallard (A. platyrhynchos) in New Zealand." Notornis 64, no. 4 (2017): 211. https://doi.org/10.63172/098959colcab.

Der volle Inhalt der Quelle
Annotation:
Change in the relative abundance of grey duck (Anas superciliosa) and mallard (A. platyrhynchos) in New Zealand, from 1950 to the present day, is summarised from trapping records, hunters’ kills, and field studies. Mallards achieved numerical ascendency over grey duck throughout most of New Zealand by the late 1970s, merely 20 years after the cessation of mallard releases by historic acclimatisation societies. Post-1990, the relative abundance of mallard in almost all districts, as recorded from hunters’ kills, appears to have stabilised at 90%, or higher. Uncertainty about hunters’ and the pu
APA, Harvard, Vancouver, ISO und andere Zitierweisen
6

Samsonov, E. V., S. G. Shikhranov, and A. M. Samsonova. "JUSTIFICATION OF THE TIMING OF THE OPENING OF SUMMER-AUTUMN AMATEUR AND SPORTS HUNTING FOR WATERFOWL IN THE NORTH OF THE LOWER VOLGA." Scientific Life 16, no. 7 (2021): 945–59. http://dx.doi.org/10.35679/1991-9476-2021-16-7-945-959.

Der volle Inhalt der Quelle
Annotation:
In accordance with Russian legislation, the timing of hunting for game birds can be adjusted at the regional level. Biological justification can be crucial in determining the timing of the hunt, namely the timing of the start and end of the hunting season. Based on the registration of waterfowl, a biological justification for the timing of the opening of hunting in the summer-autumn and autumn-winter seasons is given. The studies were carried out in the Saratov region in the water area of the Volga River (Volgograd reservoir). A total of 7 surveys were carried out, the total length of the surv
APA, Harvard, Vancouver, ISO und andere Zitierweisen
7

Green, Andy J. "Comparative feeding behaviour and niche organization in a Mediterranean duck community." Canadian Journal of Zoology 76, no. 3 (1998): 500–507. http://dx.doi.org/10.1139/z97-221.

Der volle Inhalt der Quelle
Annotation:
Feeding behaviour of the Marbled Teal, Marmaronetta angustirostris, Mallard, Anas platyrhynchos, Garganey, Anas querquedula, and Ferruginous Duck, Aythya nyroca, in the Göksu Delta, Turkey, was compared from 10 July to 6 August 1995. Almost all individuals observed were postbreeding adults and juveniles. Marbled Teal fed closest to the surface (mean depth within the water column 8.4 cm), chiefly by bill dipping (66%) and gleaning (14%). Garganey fed at a mean depth of 9.1 cm, mainly by bill dipping (57%) and neck dipping (35%). Mallards fed at greater depths (mean 31.8 cm), mainly by upending
APA, Harvard, Vancouver, ISO und andere Zitierweisen
8

Ankney, C. Davison, Darrell G. Dennis, Lisa N. Wishard, and James E. Seeb. "Low Genic Variation between Black Ducks and Mallards." Auk 103, no. 4 (1986): 701–9. http://dx.doi.org/10.1093/auk/103.4.701.

Der volle Inhalt der Quelle
Annotation:
Abstract We used allozyme electrophoresis to estimate the degree of genetic differentiation among allopatric and sympatric populations of American Black Ducks (Anas rubripes) and Mallards (A. platyrhynchos). Mallards were collected in California, Saskatchewan, Manitoba, and Ontario, and Black Ducks were collected in Newfoundland, Nova Scotia, and Ontario. The mean genetic distances, D̄, between Black Duck populations (0.0007), between Mallard populations (0.0010), and between Mallard and Black Duck populations (0.0006) were virtually identical; there was as much genetic differentiation within
APA, Harvard, Vancouver, ISO und andere Zitierweisen
9

Han, Dianlei, Hairui Liu, Zhiqian Tong, Jiahang Pan, and Xinzhong Wang. "Effects of the speed on the webbed foot kinematics of mallard (Anas platyrhynchos)." PeerJ 11 (May 15, 2023): e15362. http://dx.doi.org/10.7717/peerj.15362.

Der volle Inhalt der Quelle
Annotation:
In this study, the effect of the speed on the webbed foot locomotion of the mallard was analyzed based on a considerable number of reliable indoor test data. Four adult male mallards were selected for analysis, and the locomotion speed of the mallard was controlled using the treadmill at an accurate and adjustable speed. The locomotion pattern of the webbed foot of the mallard at different speeds was recorded using a high-speed camera. The changes in the position and conformation of the webbed foot during locomotion on a treadmill were tracked and analyzed using Simi-Motion kinematics software
APA, Harvard, Vancouver, ISO und andere Zitierweisen
10

Pushkova, Alina E., and Ekaterina Yu Mosolova. "Urban mallard population (Anas platyrhynchos) in Saratov: Wintering, nesting, degree of synanthropization." Izvestiya of Saratov University. Chemistry. Biology. Ecology 23, no. 4 (2023): 479–90. http://dx.doi.org/10.18500/1816-9775-2023-23-4-479-490.

Der volle Inhalt der Quelle
Annotation:
The article reflects data on year-round studies of the urban mallard population in Saratov, allowing the assessment of the condition and the study of the factors influencing its formation. An estimate of the mallard population in the winter periods of 2020–2023 is presented. It is shown that the number negatively correlates with frosts and precipitation, and there is a statistically significant positive relationship between the number of people feeding ducks and the number of mallards. The state of the wintering and nesting population is assessed according to the index of synanthropization, th
APA, Harvard, Vancouver, ISO und andere Zitierweisen
11

Evseev, Danyel, and Katharine Magor. "Innate Immune Responses to Avian Influenza Viruses in Ducks and Chickens." Veterinary Sciences 6, no. 1 (2019): 5. http://dx.doi.org/10.3390/vetsci6010005.

Der volle Inhalt der Quelle
Annotation:
Mallard ducks are important natural hosts of low pathogenic avian influenza (LPAI) viruses and many strains circulate in this reservoir and cause little harm. Some strains can be transmitted to other hosts, including chickens, and cause respiratory and systemic disease. Rarely, these highly pathogenic avian influenza (HPAI) viruses cause disease in mallards, while chickens are highly susceptible. The long co-evolution of mallard ducks with influenza viruses has undoubtedly fine-tuned many immunological host–pathogen interactions to confer resistance to disease, which are poorly understood. Her
APA, Harvard, Vancouver, ISO und andere Zitierweisen
12

Bordjan, Dejan. "The Mallard Anas platyrhynchos in Slovenia: a review with an estimation of its current population." Acrocephalus 41, no. 186-187 (2020): 69–118. http://dx.doi.org/10.2478/acro-2020-0006.

Der volle Inhalt der Quelle
Annotation:
Abstract Although the Mallard is one of the most numerous and best-studied waterbirds in the world, it received almost no attention in Slovenia. It is one of the most frequently observed waterbirds in our country, with frequency often reaching 100%. Sites with lower frequency either freeze in winter or have a low number of individuals to start with. The Mallard is also the most dominant species (17.5% and 89.0%) with higher dominance at sites less suitable for waterbirds due to the lack of available shoals. Mallards reach their maximum numbers during fall migration and winter. Spring migration
APA, Harvard, Vancouver, ISO und andere Zitierweisen
13

Yetter, Aaron P., Joshua D. Stafford, Christopher S. Hine, Matthew W. Bowyer, Stephen P. Havera, and Michelle M. Horath. "Nesting Biology of Mallards in West-central Illinois." Illinois Natural History Survey Bulletin 39, no. 1-6 (2009): 1–38. http://dx.doi.org/10.21900/j.inhs.v39.95.

Der volle Inhalt der Quelle
Annotation:
The number of Mallards (Anas platyrhynchos) breeding in Illinois and eastern North America has increased in recent decades; however, few studies have investigated the nesting biology of Mallards outside primary production areas. Therefore, we radiomarked resident female Mallards (n = 148) in west-central Illinois during 1998–2003 to assess nesting parameters and evaluate recruitment. Mean initiation date for first nests ranged from 22 April to 6 May, and the majority (75%) of nests were initiated by 20 May. Therefore, the majority of nests were predicted to hatch by 24 June. The nesting season
APA, Harvard, Vancouver, ISO und andere Zitierweisen
14

Wells-Berlin, Alicia M., Harold H. Prince, and Todd W. Arnold. "Incubation Length of Dabbling Ducks." Condor 107, no. 4 (2005): 926–29. http://dx.doi.org/10.1093/condor/107.4.926.

Der volle Inhalt der Quelle
Annotation:
AbstractWe collected unincubated eggs from wild Mallard (Anas platyrhynchos), Gadwall (A. strepera), Blue-winged Teal (A. discors), and Northern Shoveler (A. clypeata) nests and artificially incubated them at 37.5°C. Average incubation lengths of Mallard, Gadwall, and Northern Shoveler eggs did not differ from their wild-nesting counterparts, but artificially incubated Blue-winged Teal eggs required an additional 1.7 days to hatch, suggesting that wild-nesting teal incubated more effectively. A small sample of Mallard, Gadwall, and Northern Shoveler eggs artificially incubated at 38.3°C hatche
APA, Harvard, Vancouver, ISO und andere Zitierweisen
15

D'Eon, Robert G., Norman R. Seymour, and Arnold H. Boer. "Black duck – mallard behavioural interactions in relation to hybridization." Canadian Journal of Zoology 72, no. 8 (1994): 1517–21. http://dx.doi.org/10.1139/z94-200.

Der volle Inhalt der Quelle
Annotation:
Black duck (Anas rubripes) numbers have declined over the past several decades in conjunction with a gradual eastward range expansion of the mallard (Anas platyrhynchos). Introgressive hybridization has been proposed as a principal cause of this decline. We studied a sympatric population of black ducks and mallards to determine the relative contribution of forced copulation and mixed pairs to hybrid production and test the common belief that mallards are more aggressive than black ducks. Mixed pairs (14% of all pairs), not interspecific forced copulation, likely accounted for the 2% hybridizat
APA, Harvard, Vancouver, ISO und andere Zitierweisen
16

Hanson, Alan R., C. Davison Ankney, and Darrell G. Dennis. "Body weight and lipid reserves of American Black Ducks and Mallards during autumn." Canadian Journal of Zoology 68, no. 10 (1990): 2098–104. http://dx.doi.org/10.1139/z90-292.

Der volle Inhalt der Quelle
Annotation:
A comparison of body weight and lipid reserves (weights of mesenteric and abdominal fat) of American Black Ducks (Anas rubripes) and Mallards (Anas platyrhynchos) during autumn was done to provide insight regarding the recent contemporaneous decline in Black Duck and increase in Mallard populations of eastern North America. Data were collected on 350 Black Ducks and 1477 Mallards shot by hunters in southwestern Ontario from September 24 to December 20, 1986. Date shot and fresh body weight were recorded, and the head, a wing, a foot, and the viscera were removed and frozen. Body weight and lip
APA, Harvard, Vancouver, ISO und andere Zitierweisen
17

Bengtsson, Daniel, Kamran Safi, Alexis Avril, et al. "Does influenza A virus infection affect movement behaviour during stopover in its wild reservoir host?" Royal Society Open Science 3, no. 2 (2016): 150633. http://dx.doi.org/10.1098/rsos.150633.

Der volle Inhalt der Quelle
Annotation:
The last decade has seen a surge in research on avian influenza A viruses (IAVs), in part fuelled by the emergence, spread and potential zoonotic importance of highly pathogenic virus subtypes. The mallard ( Anas platyrhynchos ) is the most numerous and widespread dabbling duck in the world, and one of the most important natural hosts for studying IAV transmission dynamics. In order to predict the likelihood of IAV transmission between individual ducks and to other hosts, as well as between geographical regions, it is important to understand how IAV infection affects the host. In this study, w
APA, Harvard, Vancouver, ISO und andere Zitierweisen
18

Bombik, Elżbieta, Katarzyna Pietrzkiewicz, and Antoni Bombik. "Analysis of the Fatty Acid Profile of the Tissues of Hunted Mallard Ducks (Anas platyrhynchos L.) from Poland." Animals 12, no. 18 (2022): 2394. http://dx.doi.org/10.3390/ani12182394.

Der volle Inhalt der Quelle
Annotation:
The aim of the study was to analyse the fatty acid profile of selected tissues of mallard ducks (Anas platyrhynchos L.), in relation to where they were obtained and their sex, with regard to the human diet. The study was carried out on material obtained from mallard ducks from two study areas: the Siedlce hunting district and the Leszno hunting district. The research material was the breast and leg muscles of 28 mallards. The samples were frozen and stored at −20 °C. The fatty acid profiles in the biological samples were determined by selected ion recording (SIR). The results showed significan
APA, Harvard, Vancouver, ISO und andere Zitierweisen
19

Tidwell, Paul R., Elisabeth B. Webb, Mark P. Vrtiska, and Andrew A. Bishop. "Diets and Food Selection of Female Mallards and Blue-Winged Teal During Spring Migration." Journal of Fish and Wildlife Management 4, no. 1 (2013): 63–74. http://dx.doi.org/10.3996/072012-jfwm-062.

Der volle Inhalt der Quelle
Annotation:
Abstract Waterfowl nutritional requirements and food availability at migration stopover habitats may differ from those at nesting or wintering areas. Although there is little information on factors that influence waterfowl diets and food selection during migration, we hypothesized that bird age and wetland density in the surrounding landscape would influence food selection. Thus, the objective of this study was to quantify mallard Anas platyrhynchos and blue-winged teal Anas discors diets during migration and evaluate effects of age and wetland density on waterfowl food selection. We collected
APA, Harvard, Vancouver, ISO und andere Zitierweisen
20

Hayes, Floyd E., Drielly N. Martins, and Christian X. Nunez. "Social and Sexual Behavior of Intersex Mallards: A Literature Review and a New Case Study." Western Birds 55, no. 2 (2024): 130–36. http://dx.doi.org/10.21199/wb55.2.4.

Der volle Inhalt der Quelle
Annotation:
Spontaneous sex reversal is a form of intersexuality in which one sex, usually a female, acquires traits of the other sex. We reviewed previously published accounts of intersex Mallards (Anas platyrhynchos) resulting from sex reversal, of which four individuals behaved as females and four behaved as males, and two of the latter mounted other females. Video analyses of an intersex Mallard in Napa, Napa County, California, revealed that it was less social, spending much more time alone than either sex of normal Mallards during the breeding season, and behaved like a female by spending much more
APA, Harvard, Vancouver, ISO und andere Zitierweisen
21

Bombik, Elżbieta, Antoni Bombik, and Katarzyna Pietrzkiewicz. "Analysis of Zinc and Copper Content in Selected Tissues and Organs of Wild Mallard Ducks (Anas platyrhynchos L.) in Poland." Animals 14, no. 8 (2024): 1176. http://dx.doi.org/10.3390/ani14081176.

Der volle Inhalt der Quelle
Annotation:
The research material included selected muscles and liver of mallard ducks obtained in two research areas. A total of 28 mallards were obtained for the study—six males and six females from the Siedlce hunting district and eight males and eight females from the Leszno hunting district. Zinc and copper concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP OES). It was concluded from the study that the Leszno hunting district is more polluted than the Siedlce hunting district. Among the examined tissues of mallard ducks from both hunting districts, the hi
APA, Harvard, Vancouver, ISO und andere Zitierweisen
22

Boyer, Ryan A., John M. Coluccy, Robert A. Montgomery, Kyle M. Redilla, and Scott R. Winterstein. "The effect of habitat on the breeding season survival of Mallards (Anas platyrhynchos) in the Great Lakes region." Canadian Journal of Zoology 96, no. 7 (2018): 700–706. http://dx.doi.org/10.1139/cjz-2017-0224.

Der volle Inhalt der Quelle
Annotation:
Modeling the effect of habitat on animal survival is critical for understanding population dynamics and developing effective habitat management strategies. Despite the importance of this information, knowledge of survival–habitat associations are often lacking, particularly for waterfowl species. Here we evaluated female Mallard (Anas platyrhynchos Linnaeus, 1758) survival during the breeding season in relation to habitat conditions within each individual’s home range. We implanted telemetry transmitters and tracked 283 female Mallards across nine study sites in the Great Lakes region. For eac
APA, Harvard, Vancouver, ISO und andere Zitierweisen
23

Abood, Dhyaa Ab. "Comparative anatomical and histological features of the kidney in Harrier (Circus aueroginosus), Chicken (Gallus domesticus) and Mallard duck (Anas platyrhynchos." Iraqi Journal of Veterinary Medicine 38, no. 1 (2014): 107–13. http://dx.doi.org/10.30539/iraqijvm.v38i1.262.

Der volle Inhalt der Quelle
Annotation:
The aim of this study was to compare anatomical and histological of the kidney in three type of birds. The study revealed that, in harrier species the cranial lobe of kidney was the largest with elongated shape. In mallard the cranial lobe was small round-oval, while middle and caudal lobe were lobulated and larger .In chicken the caudal lobe was the largest. Statistically, in harrier the mean length of cranial lobe (20±0.1mm) and the width of the middle lobe (5±0.5mm) were significantly higher than those of mallard (10±0.3mm) (8.0.2mm) and chicken (15±0.2mm) (4±0.4mm) respectively. The mean w
APA, Harvard, Vancouver, ISO und andere Zitierweisen
24

Bombik, Elżbieta, Antoni Bombik, and Katarzyna Pietrzkiewicz. "Content of Lead and Cadmium in the Tissues and Organs of the Wild Mallard Duck (Anas platyrhynchos L.) Depending on the Region of Poland Where It Is Harvested." Animals 13, no. 21 (2023): 3327. http://dx.doi.org/10.3390/ani13213327.

Der volle Inhalt der Quelle
Annotation:
A property common to heavy metals is that even in small concentrations they can exert toxic effects on living organisms, including humans. The aim of this study was to analyze the quality of the tissues and organs of wild mallard ducks (Anas platyrhynchos L.) by estimating the potential hygiene and toxicological hazard associated with the concentrations of lead and cadmium in these tissues and organs, as well as the influence of the birds’ sex and place of origin on these parameters. A significantly higher average lead content was noted in the breast muscles and the livers of the mallards harv
APA, Harvard, Vancouver, ISO und andere Zitierweisen
25

Dwyer, Chris P., and Guy A. Baldassarre. "Habitat use by sympatric female mallards and American black ducks breeding in a forested environment." Canadian Journal of Zoology 72, no. 9 (1994): 1538–42. http://dx.doi.org/10.1139/z94-204.

Der volle Inhalt der Quelle
Annotation:
There has been much speculation regarding whether breeding mallards (Anas platyrhynchos) and American black ducks (A. rubripes) use similar habitat types in forested areas, which could lead to increased interspecific contact. To study this issue, we used radiotelemetry during 1990–1991 on sympatric female mallards and black ducks breeding in the western Adirondack Mountains of New York. Mallard and black duck pairs occupied the general area at a density of 0.7 and 0.6/km2, respectively. Black duck home ranges tended to be larger than those of mallards, although the difference was not significa
APA, Harvard, Vancouver, ISO und andere Zitierweisen
26

Guenin, Shane, Carson J. Pakula, Jonathon Skaggs, Esteban Fernández-Juricic, and Travis L. DeVault. "Inefficacy of mallard flight responses to approaching vehicles." PeerJ 12 (September 25, 2024): e18124. http://dx.doi.org/10.7717/peerj.18124.

Der volle Inhalt der Quelle
Annotation:
Vehicle collisions with birds are financially costly and dangerous to humans and animals. To reduce collisions, it is necessary to understand how birds respond to approaching vehicles. We used simulated (i.e., animals exposed to video playback) and real vehicle approaches with mallards (Anas platyrynchos) to quantify flight behavior and probability of collision under different vehicle speeds and times of day (day vs. night). Birds exposed to simulated nighttime approaches exhibited reduced probability of attempting escape, but when escape was attempted, fled with more time before collision com
APA, Harvard, Vancouver, ISO und andere Zitierweisen
27

Einarson, Daniel, Fredrik Frisk, Kamilla Klonowska, and Charlotte Sennersten. "A Machine Learning Approach to Simulation of Mallard Movements." Applied Sciences 14, no. 3 (2024): 1280. http://dx.doi.org/10.3390/app14031280.

Der volle Inhalt der Quelle
Annotation:
Machine learning (ML) is increasingly used in diverse fields, including animal behavior research. However, its application to ambiguous data requires careful consideration to avoid uncritical interpretations. This paper extends prior research on ringed mallards where sensors revealed their movements in southern Sweden, particularly in areas with small lakes. The primary focus is to distinguish the movement patterns of wild and farmed mallards. While well-known statistical methods can capture such differences, ML also provides opportunities to simulate behaviors outside of the core study span.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
28

Salman, Alp, Irmak Kurtul, and Hasan Musa Sarı. "The remarkable observation for a mallard (Anas platyrhynchos) food from estuarine/coastal area (İzmir/Turkey): A mosquitofish (Gambusia holbrooki)." Ege Journal of Fisheries and Aquatic Sciences 39, no. 3 (2022): 191–96. http://dx.doi.org/10.12714/egejfas.39.3.03.

Der volle Inhalt der Quelle
Annotation:
The purpose of this study is to create awareness about the species of mosquito fishes (Gambusia holbrooki Girard, 1859) both vectors and ways of introduction to new aquatic habitats. Because the species creates risks, especially for the circumstance of the native and endemic fish fauna, studies about introduction stories of the species are quite important to prevent the risk. In the current report, mosquitofishes which are known as a highly invasive species were found in the crop content of a hen mallard duck (Anas platyrhynchos L., 1758) in an estuarine area, the Gediz River Basin (İzmir, Tur
APA, Harvard, Vancouver, ISO und andere Zitierweisen
29

Taylor-Burt, Kari R., Nicolai Konow, and Andrew A. Biewener. "Post-activation muscle potentiation and its relevance to cyclical behaviours." Biology Letters 16, no. 6 (2020): 20200255. http://dx.doi.org/10.1098/rsbl.2020.0255.

Der volle Inhalt der Quelle
Annotation:
Muscle can experience post-activation potentiation (PAP), a temporary increase in force and rate of force development, when contractions are closely timed; therefore, cyclical behaviours are likely affected by PAP, as succeeding contraction cycles can lead to potentiation over several subsequent cycles. Here, we examined PAP during in situ cyclical contractions of the mallard lateral gastrocnemius (LG). Surface swimming, a cyclical behaviour, was mimicked with work-loops using in vivo LG length change and stimulation parameters. Tests were performed at mallards' preferred cycle frequency as we
APA, Harvard, Vancouver, ISO und andere Zitierweisen
30

Dyer, John, and Murray Williams. "An introduction most determined: Mallard (Anas platyrhynchos) to New Zealand." Notornis 57, no. 4 (2010): 178. https://doi.org/10.63172/399767fehrlu.

Der volle Inhalt der Quelle
Annotation:
The introductions of mallard (Anas platyrhynchos) to New Zealand, and their breeding and release as a game bird by Acclimatisation Societies are summarised. We identify 19 importations, 14 of which (a total of 115 birds all from Great Britain) were sufficient to establish small feral populations in southern and central New Zealand by about 1910. Five subsequent importations were made by Aucklander C.A. Whitney, 3 from Great Britain in 1910 (6 birds), 1914 (number unconfirmed) and 1927 (393 birds), followed by 99 birds (1937) and 45 eggs (1941) both from the USA. It was Whitney’s distribution o
APA, Harvard, Vancouver, ISO und andere Zitierweisen
31

Olayta, Jayson N., and Via Marie C Cajano. "The Philippine Mallard Duck (Anas platyrhynchos) Business in Eastern, Laguna, Philippines." International Journal of Advanced Multidisciplinary Research and Studies 4, no. 6 (2024): 651–57. https://doi.org/10.62225/2583049x.2024.4.6.3491.

Der volle Inhalt der Quelle
Annotation:
The study examined the status, challenges, and potentials of the Philippine Mallard Duck (Anas platyrhynchos) Business in Eastern, Laguna, focusing on understanding the current status of the business and identifying constraints and opportunities for sustainable growth. It aimed to assess the factors affecting the Philippine Mallard Duck industry in Eastern, Laguna and provide insights for enhancing its productivity, profitability, and environmental sustainability. Face to face interview using survey questionnaire was used to gather information. The data collected was analyzed through descripti
APA, Harvard, Vancouver, ISO und andere Zitierweisen
32

Madokoro, Hirokazu, Satoshi Yamamoto, Kanji Watanabe, et al. "Mallard Detection Using Microphone Arrays Combined with Delay-and-Sum Beamforming for Smart and Remote Rice–Duck Farming." Applied Sciences 12, no. 1 (2021): 108. http://dx.doi.org/10.3390/app12010108.

Der volle Inhalt der Quelle
Annotation:
This paper presents an estimation method for a sound source of pre-recorded mallard calls from acoustic information using two microphone arrays combined with delay-and-sum beamforming. Rice farming using mallards saves labor because mallards work instead of farmers. Nevertheless, the number of mallards declines when they are preyed upon by natural enemies such as crows, kites, and weasels. We consider that efficient management can be achieved by locating and identifying the locations of mallards and their natural enemies using acoustic information that can be widely sensed in a paddy field. Fo
APA, Harvard, Vancouver, ISO und andere Zitierweisen
33

Sanderson, Glen C., William L. Anderson, George L. Foley, et al. "Toxicity of Ingested Bismuth Alloy Shot in Game-farm Mallards." Illinois Natural History Survey Bulletin 35, no. 1-5 (1997): 217–52. http://dx.doi.org/10.21900/j.inhs.v35.129.

Der volle Inhalt der Quelle
Annotation:
In a 150-day study, we tested for chronic toxicity and effects on reproduction of bismuth/tin (Bi/Sn) alloy shot dosed in game-farm mallards (Anas platyrhynchos). Histopathology of livers, kidneys, gonads, hearts, and lungs showed no significant group-related differences among 0-dosed (controls), iron (Fe)-dosed (8, No. 4, steel shot), and Bi-dosed (8, No. 4, Bi/Sn alloy shot) adult ducks or among ducklings from pairs of these dosed groups. Bi shot, under our test conditions, did not elicit toxicity in mallard ducks or affect their reproduction or offspring.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
34

Hughes, M. R., D. C. Bennett, and T. M. Sullivan. "Effect of saline drinking water on the size and water content of the gut and other organs of male and female mallards." Canadian Journal of Zoology 80, no. 1 (2002): 70–76. http://dx.doi.org/10.1139/z01-206.

Der volle Inhalt der Quelle
Annotation:
Ducks absorb imbibed Na+ and water in the anterior gut and reabsorb Na+ and water from urine refluxed into the hind gut. In Mallards (Anas platyrhynchos) this process is sexually disparate: males reflux and reabsorb more water, mainly in the ceca. We examined the effect of saline acclimation on the size of Mallard organs, especially the gut and other osmoregulatory organs (kidneys, salt glands) in both sexes. We tested and accept two hypotheses: (1) saline increases the mass of the Mallard hind gut and other osmoregulatory organs and (2) saline has a greater effect on the organs of males. Drin
APA, Harvard, Vancouver, ISO und andere Zitierweisen
35

Seymour, N. R. "Forced copulation in sympatric American black ducks and mallards in Nova Scotia." Canadian Journal of Zoology 68, no. 8 (1990): 1691–96. http://dx.doi.org/10.1139/z90-249.

Der volle Inhalt der Quelle
Annotation:
Observations of primarily identifiable wild black ducks and mallards provided qualitative and quantitative descriptions of interactions within and between intraspecific, interspecific, and heterospecific pairs throughout the breeding season. The study was carried out in a watershed on the St. Lawrence estuary shore of Nova Scotia from 1972 to 1988. Attempted forced copulation and forced pair copulation were rare among black ducks at any time throughout the breeding period. Only two apparently successful forced copulations were observed. Territorial males chased both female black ducks and mall
APA, Harvard, Vancouver, ISO und andere Zitierweisen
36

Febrianto, Firman, Ismoyowati Ismoyowati, Mochamad Mufti, Prayitno Prayitno, and Dattadewi Purwantini. "Polymorphisme Gene GH and Morphological Characteristic of Anas platyrhynchos and Cairina moschata." ANIMAL PRODUCTION 20, no. 1 (2019): 17. http://dx.doi.org/10.20884/1.jap.2018.20.1.665.

Der volle Inhalt der Quelle
Annotation:
The aims of this research was to identify the qualitative and quantitative difference of the phenotypes of native mallard and Muscovy, and Muscovy the genetic diversity between Muscovy and mallard using RFLP method with growth hormone primer (GH) gene. The materials were 30-week old male and female ducks from 5 strains—Magelang, Mojosari and Tegal ducks, white-feathered, and black and white-feathered Muscovy. Muscovy Completely Randomized Design was used to analyze parameters 5 strains of ducks based on gender and with 5 replications. The parameters measured were local and Muscovy duck phenoty
APA, Harvard, Vancouver, ISO und andere Zitierweisen
37

Sheldon, William. "The Last Mallard." Organization & Environment 11, no. 4 (1998): 477. http://dx.doi.org/10.1177/0921810698114016.

Der volle Inhalt der Quelle
APA, Harvard, Vancouver, ISO und andere Zitierweisen
38

Bartel, Riley D., Jennifer L. Sheppard, Ádám Lovas-Kiss, and Andy J. Green. "Endozoochory by mallard in New Zealand: what seeds are dispersed and how far?" PeerJ 6 (May 23, 2018): e4811. http://dx.doi.org/10.7717/peerj.4811.

Der volle Inhalt der Quelle
Annotation:
In Europe and North America waterfowl are major dispersers of aquatic and terrestrial plants, but in New Zealand their role has yet to be investigated. Mallards were introduced to New Zealand in the late 1800s, and today they are the most abundant and widespread waterfowl in the country. To assess seed dispersal, we radiomarked 284 female mallards from two study sites during the pre-breeding (June–August) and breeding (August–December) periods in 2014–2015, and examined movements that occurred within 24, 48 or 72 h when seed dispersal by endozoochory is considered likely. During June and July
APA, Harvard, Vancouver, ISO und andere Zitierweisen
39

Guay, P.-J., A. Taysom, R. Robinson, and J. P. Tracey. "Hybridization between the Mallard and native dabbling ducks: causes, consequences and management." Pacific Conservation Biology 20, no. 1 (2014): 41. http://dx.doi.org/10.1071/pc140041.

Der volle Inhalt der Quelle
Annotation:
Waterbirds are currently facing various threats throughout the world. One threat that is often overlooked is hybridization with introduced species. This threatening process is especially significant for dabbling ducks (Genus Anas). The Mallard (Anas platyrhynchos) has been introduced to various parts of the world and now hybridizes and threatens numerous Anas species. In this paper, we review hybridization between Mallards and dabbling ducks with a specific emphasis on threats to the Pacific Black Duck (A. superciliosa). We then present an overview of the potential mechanisms of hybridization
APA, Harvard, Vancouver, ISO und andere Zitierweisen
40

Nummi, Petri. "Food-niche relationships of sympatric mallards and green-winged teals." Canadian Journal of Zoology 71, no. 1 (1993): 49–55. http://dx.doi.org/10.1139/z93-008.

Der volle Inhalt der Quelle
Annotation:
Diets of juvenile green-winged teals (Anas crecca) and mallards (A. platyrhynchos) in August and September were studied with respect to (i) the proportion of animal and plant matter. (ii) prey size. (iii) prey diversity, and (iv) the vertical distribution of invertebrate prey in the water column. The size distribution of prey in the diets of the ducks was also compared with that in the environment. Teal diets contained a larger and more variable fraction of invertebrates than did mallard diets. Teals used more small food items than did mallards; however, both used a wide spectrum of sizes. Tea
APA, Harvard, Vancouver, ISO und andere Zitierweisen
41

Fedynich, Alan M., and Danny B. Pence. "Helminth community structure and pattern in a migratory host (Anas platyrhynchos)." Canadian Journal of Zoology 72, no. 3 (1994): 496–505. http://dx.doi.org/10.1139/z94-067.

Der volle Inhalt der Quelle
Annotation:
The helminth community at the southern periphery of the mallard (Anas platyrhynchos) breeding range on the Southern High Plains of Texas consisted of species commonly reported in this host at northern latitudes. Although prevalence, abundance, and dominance values varied and this helminth community was species-rich and diverse, species composition was relatively consistent over temporal and host variables. Mallards had higher mean abundances of helminths in summer than winter; 80% of all helminth individuals occurred in juveniles. Recurrent groups formed during summer and within juvenile malla
APA, Harvard, Vancouver, ISO und andere Zitierweisen
42

Krementz, David G., Kwasi Asante, and Luke W. Naylor. "Autumn Migration of Mississippi Flyway Mallards as Determined by Satellite Telemetry." Journal of Fish and Wildlife Management 3, no. 2 (2012): 238–51. http://dx.doi.org/10.3996/022012-jfwm-019.

Der volle Inhalt der Quelle
Annotation:
Abstract We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17–December 7). For those mallards that stopped for >1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a
APA, Harvard, Vancouver, ISO und andere Zitierweisen
43

Bradecina, Joanna Marie. "Growth Performance of Mallard Ducks Fed Soybean Curd Residue (SCR) as Partial Replacement for Soybean Meal." Southeast Asian Journal of Agriculture and Allied Sciences 1, no. 1 (2022): 46–57. https://doi.org/10.63943/sajaas.vol1iss1art6pp46-57.

Der volle Inhalt der Quelle
Annotation:
To evaluate the production performance of male and female mallard ducks fed soybean curd residue as a partial replacement for soybean meal, a study was conducted from April 6, 2020, to June 6, 2020, at Buhol na Mangga, San Ildefonso, Bulacan. One hundred eighty mallard ducks (90 male and 90 female) were used in the study with a two-factor factorial experiment in Completely Randomized Design (CRD). Factor A was the level of substitution (basal feeds formulated duck starter/grower feeds, soybean curd residue as 15% replacement for soybean meal in formulated duck starter/grower feeds and soybean
APA, Harvard, Vancouver, ISO und andere Zitierweisen
44

Schott, Renée. "Surgical Repair of Ankyloblepharon in Mallards (Anas platyrhynchos)." Wildlife Rehabilitation Bulletin 26, no. 2 (2008): 31–35. http://dx.doi.org/10.53607/wrb.v26.151.

Der volle Inhalt der Quelle
Annotation:
Congenital and acquired ankyloblepharon (complete fusion of the upper and lower eyelids) have been documented in birds (Buyukmihci et al 1990; Pinard et al 2006). Surgical repair of ankyloblepharon in cockatiels (Nymphicus spp.) has been reported as unsuccessful in four cases of presumed congenital origin and successful in one case of acquired ankyloblepharon (Buyukmihci et al 1990; Pinard et al 2006). Two mallards (Anas platyrhynchos) with ankyloblepharon were treated with surgical reconstruction of the eyelids to restore bilateral vision. The first mallard presented as a one–week old orphan.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
45

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.

Der volle Inhalt der Quelle
Annotation:
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 du
APA, Harvard, Vancouver, ISO und andere Zitierweisen
46

Mack, Glenn G., Robert G. Clark, and David W. Howerter. "Size and habitat composition of female mallard home ranges in the prairie-parkland region of Canada." Canadian Journal of Zoology 81, no. 8 (2003): 1454–61. http://dx.doi.org/10.1139/z03-136.

Der volle Inhalt der Quelle
Annotation:
Wetland density is believed to be an important determinant of variation in size of mallard (Anas platyrhynchos) home ranges, but hypothesized effects of upland habitat and female size and age have not been adequately evaluated. Thus, we investigated correlates of home-range size using unique radio-tracking data for 131 female mallards studied on 12 Canadian prairie-parkland sites in 1995–1998. Home-range size and habitat composition varied within and among study areas; overall, variation in home-range size was best modeled to include effects of seasonal and semipermanent wetlands (β = –0.06 ±
APA, Harvard, Vancouver, ISO und andere Zitierweisen
47

Stewart, Cohen, and Matthew McDougall. "Can small-scale predator control influence mallard duck (Anas platyrhynchos) nest survival? An experiment with artificial nests in Southland, New Zealand." Notornis 69, no. 1 (2022): 45. https://doi.org/10.63172/444682ccxvyr.

Der volle Inhalt der Quelle
Annotation:
Artificial mallard (Anas platyrhynchos) nests were used to identify potential nest predators and assess whether small, farm-scale predator control could reduce mallard nest predation in Southland, New Zealand. Artificial nests were deployed over the mallard nesting period (late winter – spring) in both 2019 and 2020 and monitored with motion detection cameras. Prior to 2020 artificial nest deployment, farm-scale trapping of mammalian predators was conducted on one farm whilst the other was left as a control. Feral cats (Felis catus), brushtail possums (Trichosurus vulpecula), and European hedg
APA, Harvard, Vancouver, ISO und andere Zitierweisen
48

Torrella, J. R., V. Fouces, and G. Viscor. "Descriptive and functional morphometry of skeletal muscle fibres in wild birds." Canadian Journal of Zoology 77, no. 5 (1999): 724–36. http://dx.doi.org/10.1139/z99-011.

Der volle Inhalt der Quelle
Annotation:
The fibre types of four forelimb and two hind-limb muscles involved in locomotion were morphometrically analyzed in three species of wild birds: the mallard (Anas platyrhynchos), common coot (Fulica atra), and yellow-legged gull (Larus cachinnans). Fibre cross-sectional area and perimeter, maximal diffusion distance, and number of capillaries per fibre were measured and the functional implications and physiological demands of the muscles of each species were inferred. In general, all morphometric values were lower in oxidative fibres than in anaerobic fibres, indicating that the supply of oxyg
APA, Harvard, Vancouver, ISO und andere Zitierweisen
49

Wood, Jamie R., and Christopher J. Garden. "Seasonal variation in duck populations on the Waihopai River, Invercargill, New Zealand." Notornis 57, no. 2 (2010): 57. https://doi.org/10.63172/396186cfihqg.

Der volle Inhalt der Quelle
Annotation:
Seasonal variation in size of duck populations was examined using weekly surveys along a 1.5 km section of the Waihopai River, Invercargill, New Zealand, between Jul 1995 and Jul 1996. Six species were recorded: mallard (Anas platyrhynchos) (n = 8307), New Zealand shoveler (A. variegata) (n = 285), grey duck (A. superciliosa) (n = 36), paradise shelduck (Tadorna variegata) (n = 4), grey teal (A. gracilis) (n = 1), and New Zealand scaup (Aythya novaeseelandiae) (n = 1). Asynchronous seasonal trends were observed for mallard/grey duck and shoveler populations: mallard/grey duck numbers peaked du
APA, Harvard, Vancouver, ISO und andere Zitierweisen
50

Karaca, T., M. Cemek, and M. Kanter. "Lipid Peroxidation, Antioxidant Level, and Alpha Naphthyl Acetate Esterase Activity of Peripheral Blood Lymphocytes in the Mallard, Muscovy and Pekin Ducks." Acta Veterinaria Brno 75, no. 1 (2006): 33–38. http://dx.doi.org/10.2754/avb200675010033.

Der volle Inhalt der Quelle
Annotation:
The aim of this study was to determine blood levels of malondialdehyde (MDA), reduced glutathione (GSH), ceruloplasmin and vitamin C, and the percentages of peripheral blood Tlymphocytes using the alpha-naphthyl acetate esterase (ANAE) method on Mallard (Anas platyrhynchos), Muscovy (Cairina moschata) and Pekin (Anas domestica) ducks. Blood samples were obtained from 8 adult ducks of each breed. The serum levels observed in Mallard, Muscovy and Pekin ducks respectively were 0.8, 1.07 and 1.3 nmol MDA per ml; 77.4, 66.9 and 78.7 mg GSH per 100 ml; 23.9, 26.1 and 24.1 mg ceruloplasmin per 100 ml
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Wir bieten Rabatte auf alle Premium-Pläne für Autoren, deren Werke in thematische Literatursammlungen aufgenommen wurden. Kontaktieren Sie uns, um einen einzigartigen Promo-Code zu erhalten!