Bibliografie tematiche / Mallard

Letteratura scientifica selezionata sul tema "Mallard"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 5 marzo 2023

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Articoli di riviste sul tema "Mallard"

Gillespie, Grant D. "Hybridization, Introgression, and Morphometric Differentiation between Mallard (Anas platyrhynchos) and Grey Duck (Anas superciliosa) in Otago, New Zealand". Auk 102, n. 3 (1 luglio 1985): 459–69. http://dx.doi.org/10.1093/auk/102.3.459.

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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 Ducks was achieved using a stepwise cluster analysis of mensural characters. The observed morphometric differentiation was not continuous throughout the Otago population, and a total of 5 discontinuities (groups of morphologically similar birds) were distinguished: male Mallards, female Mallards, Grey Ducks, and 2 groups of hybrid birds. The use of bivariate scattergrams of skull length and eye-lens weight provided the most useful illustration of the distinctions among Mallard, hybrid, and Grey Duck populations. As a consequence of hybridization, two morphologically distinct hybrid populations have been produced: one resembles the Grey Duck and the other the Mallard. This situation is discussed in relation to the two hybrid forms of the Marianas Mallard (A. oustaleti). The Mallard was so successful in newly created agricultural habitat that by 1958 this species constituted 53% of the Mallard-Grey Duck population. Prior to 1958 the observed hybrid frequency was less than 3% and the reduction in the proportion of the Grey Duck most probably was the result of habitat reduction. In 1977 the Mallard comprised 82% of the Mallard-Grey Duck population, and there was concern over the number of pure Grey Ducks remaining in Otago. By 1981-1982 levels of hybridization, based on plumage analysis, had reached 51%, and the proportion of pure Grey Ducks had dropped to 4.5%, which is below the level suggested for the maintenance of a species. In the absence of reproductive isolation or antihybridization mechanisms between these two species, the Mallard and hybrid populations represent a potential threat to the conservation of the New Zealand Grey Duck.

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Samsonov, E. V., S. G. Shikhranov e 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, n. 7 (2021): 945–59. http://dx.doi.org/10.35679/1991-9476-2021-16-7-945-959.

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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 survey routes was 100.6 km. The dominant species in the brood period is the mallard. Shares of recorded birds: mallard (Anas platyrhynchos L, 1758) - 96.6%, coot (Fulica atra L, 1758) - 2.5%, teal-cattle (Anas querquedula L, 1758) - 0.9%. The beginning of the mallard incubation period in 2020 is the first decade of May. The period of mass incubation of masonry by mallards is from the third decade of May to the second decade of June. The first mallard chicks appeared in the third decade of May. From the second decade of June to the second decade of July - the period of mass appearance of mallard chicks. The proportion of non-flying young mallards in the second decade of August was 33.3%, in the third decade of August - 28.3%. The end of the period of mass rise of young mallards "on the wing" took place in the first ten days of September, the proportion of non-flying young mallards in this period amounted to 4.3%. The increase in the number of mallards in the second and third ten days of July amounted to 142.0%. The beginning of the migratory summer-autumn period of 2020 (for species that do not tend to nest in the study area) fell on the first ten days of September. Biologically substantiated period for the opening of hunting in the summer-autumn and autumn-winter season is the first ten days of September (the share of non-flying young animals is less than 10%).

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Green, Andy J. "Comparative feeding behaviour and niche organization in a Mediterranean duck community". Canadian Journal of Zoology 76, n. 3 (1 marzo 1998): 500–507. http://dx.doi.org/10.1139/z97-221.

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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 (tipping 46%) and neck dipping (41%). Ferruginous Ducks fed at the greatest depths (mean 38.4 cm), chiefly by diving (76%). Marbled Teal moved most frequently between feeding events and Mallards moved least frequently. As in previous studies of dabbling ducks, the largest species (Mallard) upended more and fed deeper in the water column. However, Mallards used shallower microhabitats than smaller dabbling ducks. Dabbling and diving duck guilds were not discernible in either horizontal (feeding habitat) or vertical (feeding behaviour) niche dimensions, and the Mallard and Ferruginous Duck were related in both dimensions. Niche overlaps between species pairs along the two dimensions were negatively correlated (r = -0.71, P = 0.12), supporting niche complementarity.

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Ankney, C. Davison, Darrell G. Dennis, Lisa N. Wishard e James E. Seeb. "Low Genic Variation between Black Ducks and Mallards". Auk 103, n. 4 (1 ottobre 1986): 701–9. http://dx.doi.org/10.1093/auk/103.4.701.

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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 the two species as there was between them. Such small genetic distances are characteristic of local populations of avian species in other orders, and are consistent with what is known about the lack of reproductive isolation between Black Ducks and Mallards. Although the two taxa are still somewhat split on an east-west basis, our genetic data do not support even subspecific status for the Black Duck.

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Evseev, Danyel, e Katharine Magor. "Innate Immune Responses to Avian Influenza Viruses in Ducks and Chickens". Veterinary Sciences 6, n. 1 (10 gennaio 2019): 5. http://dx.doi.org/10.3390/vetsci6010005.

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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. Here, we compare innate responses to different avian influenza viruses in ducks and chickens to reveal differences that point to potential mechanisms of disease resistance. Mallard ducks are permissive to LPAI replication in their intestinal tissues without overtly compromising their fitness. In contrast, the mallard response to HPAI infection reflects an immediate and robust induction of type I interferon and antiviral interferon stimulated genes, highlighting the importance of the RIG-I pathway. Ducks also appear to limit the duration of the response, particularly of pro-inflammatory cytokine expression. Chickens lack RIG-I, and some modulators of the signaling pathway and may be compromised in initiating an early interferon response, allowing more viral replication and consequent damage. We review current knowledge about innate response mediators to influenza infection in mallard ducks compared to chickens to gain insight into protective immune responses, and open questions for future research.

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Yetter, Aaron P., Joshua D. Stafford, Christopher S. Hine, Matthew W. Bowyer, Stephen P. Havera e Michelle M. Horath. "Nesting Biology of Mallards in West-central Illinois". Illinois Natural History Survey Bulletin 39, n. 1-6 (30 settembre 2009): 1–38. http://dx.doi.org/10.21900/j.inhs.v39.95.

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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 averaged 88 days (range: 77–103 days). The proportion of unsuccessful females that renested ranged from 50.0–85.7%, and adults were more likely to renest (75.0%) than yearlings (48.0%). Nest success ranged from 9.8–33.3% and was 19.6% overall; hen success was 28.3%. Initial brood size was 8.2 ± 0.3 ducklings, but brood size declined to 3.0 ± 0.6 ducklings by 17 days posthatch. Brood survival to 20 days was 0.759 ± 0.081, and 20-day duckling survival was 0.413 ± 0.035. Female survival during spring-summer ranged from 0.546–1.00 and averaged 0.710 ± 0.096. Likewise, estimated Mallard recruitment varied annually (range: 0.302–0.672 female ducklings/female). Assuming constant female and duckling survival, we estimated that a recruitment rate of 0.613 female ducklings/adult female was necessary to maintain a stable Mallard breeding population in west-central Illinois. Estimated Mallard reproduction and recruitment was similar to that observed in other areas of North America. Nest success and hen success approached or exceeded estimated thresholds for population stability in most years; however, hen success averaged over the study period was insufficient for local population maintenance and growth. Female survival was comparable to that observed in other studies but may have limited population growth in some years. Duckling survival was sufficient for population maintenance. Management designed to enhance hen success and brood habitat may augment Mallard recruitment in west-central Illinois.

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Wells-Berlin, Alicia M., Harold H. Prince e Todd W. Arnold. "Incubation Length of Dabbling Ducks". Condor 107, n. 4 (1 novembre 2005): 926–29. http://dx.doi.org/10.1093/condor/107.4.926.

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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 hatched 1 day sooner, indicating that incubation temperature affected incubation length. Mean incubation length of Blue-winged Teal declined by 1 day for each 11-day delay in nesting, but we found no such seasonal decline among Mallards, Gadwalls, or Northern Shovelers. There is no obvious explanation for the seasonal reduction in incubation length for Blue-winged Teal eggs incubated in a constant environment, and the phenomenon deserves further study.

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D'Eon, Robert G., Norman R. Seymour e Arnold H. Boer. "Black duck – mallard behavioural interactions in relation to hybridization". Canadian Journal of Zoology 72, n. 8 (1 agosto 1994): 1517–21. http://dx.doi.org/10.1139/z94-200.

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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% hybridization rate on the study area. Sexual and hostile aggression was greater among mallards than black ducks prior to the establishment of territories, but thereafter was similar between the two species.

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Hanson, Alan R., C. Davison Ankney e Darrell G. Dennis. "Body weight and lipid reserves of American Black Ducks and Mallards during autumn". Canadian Journal of Zoology 68, n. 10 (1 ottobre 1990): 2098–104. http://dx.doi.org/10.1139/z90-292.

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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 lipid deposits (weight of mesenteric and abdominal fat) were compared between the two species. The first principal component from an analysis of nine morphometric measurements was used as a covariate in subsequent analysis to remove variation in body weight and lipid deposits caused by differences in structural size. Although all age-sex classes of Mallards and Black Ducks stored lipids during the autumn, adult male and juvenile female Black Ducks stored less lipids than did their Mallard counterparts (P ≤ 0.01). Differences in lipid reserves during fall migration may be a proximal reason for the lower survival of adult male and juvenile Black Ducks compared with Mallards and may also influence the timing of intraspecific, and the rate of interspecifc, pair formation.

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Bengtsson, Daniel, Kamran Safi, Alexis Avril, Wolfgang Fiedler, Martin Wikelski, Gunnar Gunnarsson, Johan Elmberg, Conny Tolf, Björn Olsen e Jonas Waldenström. "Does influenza A virus infection affect movement behaviour during stopover in its wild reservoir host?" Royal Society Open Science 3, n. 2 (febbraio 2016): 150633. http://dx.doi.org/10.1098/rsos.150633.

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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, we analysed the movements of 40 mallards equipped with GPS transmitters and three-dimensional accelerometers, of which 20 were naturally infected with low pathogenic avian influenza virus (LPAIV), at a major stopover site in the Northwest European flyway. Movements differed substantially between day and night, as well as between mallards returning to the capture site and those feeding in natural habitats. However, movement patterns did not differ between LPAIV infected and uninfected birds. Hence, LPAIV infection probably does not affect mallard movements during stopover, with high possibility of virus spread along the migration route as a consequence.

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Più fonti

Tesi sul tema "Mallard"

Jöbsis, Paul D. "Muscle oxygenation and blood flow during submersion in ducks (anas platyrhynchos) and seals (phoca vitulina) /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9907822.

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Davis, Jonas Ian. "Mallard nesting ecology in the Great Lakes". CONNECT TO THIS TITLE ONLINE, 2008. http://etd.lib.umt.edu/theses/available/etd-05272008-112947/.

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Lavretsky, Philip. "PHYLOGENETICS, POPULATION GENETICS, AND EVOLUTION OF THE MALLARD COMPLEX". Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1400160673.

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Shimizu, Manabu. "Acid-base balance in arterial plasma of white Pekin duck (Anas platyrhynchos) during forced submergence and recovery". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25044.

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Acid-base balance in plasma was studied in forcibly submerged Pekin ducks (Anas platyrhynchos). All important variables determining acid-base balance (arterial CO₂ tension (PαCO₂) strong ion difference ([SID]) and total protein content which approximates total weak acid concentration in plasma) were measured. During forced submergence PαCO₂ increased and pHa steadily decreased with time. There was also an increase in [lactate⁻], which was accompanied by an increase of equal magnitude in [Na⁺]. There were no significant changes in the concentrations of other strong ions (K⁺, Ca²⁺, Mg²⁺ and Cl⁻). Strong ion difference did not change during the first two minutes of submergence, but there was about a 4 mequiv/L increase by the end of the four-minute dive. Theoretically an increase in [SID] should cause plasma to be alkaline, but since plasma became progressively acidic, this condition can only be due to the increase in PαCO₂. During recovery from dives, the plasma remained as acidic one minute after emersion as at the end of the dives. On the other hand, arterial pH slowly increased towards the pre-dive level during recovery. Arterial CO₂ tension decreased much more rapidly and was already at or below the pre-dive level one minute after emersion. Therefore, PαCO₂ could no longer affect plasma pH. There was, however, a great increase in [lactate-] in the first minute of recovery. Although [Na⁺] and [K⁺] were elevated, from pre-dive values after the four minute dive, the increase in [lactate⁻] resulted in a marked reduction in [SID]. Since there was no change in the total plasma protein content, the acidic condition observed in recovery could only be due to decreased [SID]. Breathing 0₂ before diving prevented circulatory adjustments and pH returned to pre-dive levels one minute after emersion, confirming that the acidic condition observed in recovery is a consequence of the lactate produced in the hypoperfused tissues during submergence.
Science, Faculty of
Zoology, Department of
Graduate

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Drake, Anna. "Mallard duckling care and survival at a wildlife rehabilitation center". Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31563.

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Birds are by far the largest group of wildlife cared for by wildlife rehabilitators in British Columbia, Canada. Of this group, mallards (Anas platyrhynchos) are the fifth most common species brought into care. 41% of these mallards are uninjured orphans and require only supportive care until they begin to develop their flight feathers. Although these birds are precocial, and although heat and ad lib food and water are provided, deaths are common in the period between admission and release. An analysis of 937 individual ducklings representing 6 years of data from the Wildlife Rescue Association of British Columbia showed that these deaths are concentrated in the first week after birds are admitted. Logistic regression analyses showed that ducklings that were lighter, admitted with fewer siblings, and that spent longer with the individual who found them were more likely to die in the rehabilitator's care than other individuals. In an experiment, a single, older bird was added to novice broods to act as a "mentor" during the first week of care. Nine novice broods were split at admission and reared in two groups: one housed with a mentor and the other acting as a control. Body size metrics were collected at admission and again at the end of the first week in care, and ducklings in both groups were weighed twice daily during this time. There was no significant difference in mean growth or body condition between treatment and control groups and no experimental ducklings died during the first week. Treatment groups did, however, have less spread in final body weights, mainly because the final weight of the least-thriving individual in each treatment group was significantly greater than in corresponding control groups. The fact that no deaths occurred among the experimental broods in the first week indicates that the experimental housing was better for novice broods than standard facility housing. However, as low growth rates are associated with greater risk of death, the provision of mentors to new broods may reduce the number of birds dying in care where housing is less favorable.
Land and Food Systems, Faculty of
Graduate

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Cunningham, Emma Jane Ann. "Forced copulation and sperm competition in the mallard Anas platyrhynchos". Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262851.

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Joyce, Peter. "The roles of heterogeneity and scale in mallard nest site selection". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62764.pdf.

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Muller, Wiebke. "Hybridisation, and the Conservation of the Grey Duck in New Zealand". Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/5056.

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Hybridisation is increasingly acknowledged as a conservation problem. The widespread hybridisation between grey duck (Anas superciliosa) and mallard (A. platyrhynchos) in New Zealand is a good example of a native species hybridising with a foreign one, and forms the main focus of this thesis. Mallards were introduced into New Zealand from Europe, and hybrids were soon observed. I surveyed the extent of the hybridisation on the West Coast of the South Island and found that, based on phenotype, at least half of population is now hybrids. Mallards and mallard-like hybrids dominate in the eastern South Island, while grey ducks occur only in some areas of the West Coast. Comparison with historical data suggests that the decline of the grey duck and the spread of hybrids has not stabilised and is ongoing. Contrary to expectations most grey ducks were found on agricultural land and most mallards on natural lakes or rivers, so grey ducks probably do not have an advantage over mallards on the less developed West Coast. An alternative theory is proposed here that explains the spatial distribution of hybridisation as a reflection of a temporal pattern. As mallards were first released in the east, the delay taken to cross the Southern Alps could also explain the pattern observed. This hypothesis suggests that the grey duck will persist in the southern West Coast. An analysis of the phenotypes of partners in pairs suggests that mating is positively assortative within each species and within hybrids. In fact, not a single pair of pure grey duck mated with pure mallard was observed in almost a thousand pairs, raising the question of how hybridisation started. There was a tendency for males to be more mallard-like in phenotype than their partners, suggesting there might be a selective advantage to the mallard male phenotype. This may be one factor explaining the dominance of mallards in the hybrid swarm. To analyse hybridisation at the genetic level, I analysed samples from grey ducks, mallards and domestic ducks with 11 microsatellite loci. This genotyping profile was then compared to ducks captured and shot in New Zealand. Genetic analysis confirms that the ducks in New Zealand were almost exclusively of hybrid origin. Phenotypic hybrid scores correlated with the established genotypic scores, but the correlation was imperfect, suggesting inaccuracies in either or both measures. As the spread of hybrids might be due to the differences in their fitness relative to either parent species, I compared the relative fitness of hybrid ducks using a range of health-related measures such as ecto- and endoparasite loads, immunocompetence, body condition, and heterophil to lymphocyte ratios. Overall, I found no conclusive evidence for any differences between grey duck-like and mallard-like individuals. However, as my sample consisted nearly entirely of hybrids, it is possible that fitness may differ from the parental species. To understand the outcome of hybridisation between two species, I next constructed a mathematical model to simulate hybridisation, and which allowed the specification of parameters describing mating patterns, differential survival, and differential reproductive output. The model successfully predicted the outcomes of two known hybridisation cases. In a sensitivity analysis for mallard and grey duck, the model predicted that this species pair is likely to hybridise under any set of conditions likely to be encountered across their shared range. Finally, in a study within the more general context of hybridisation, the influence of inbreeding on hybridisation rates was investigated using inbred and outbred lines of Drosophila species. I found evidence for increased hybridisation in inbred lines, and although further studies are needed to confirm the generality of this pattern, my results have implications for the management of hybridisation, and for the use of hybridisation as an adaptive strategy. In conclusion, my work suggests it is very likely that the grey duck will become extinct as a separate species in New Zealand in the near future, and that it is likely to be threatened in other areas of its range were it co-occurs with the mallard. The options for management of this situation are limited, as large areas without mallards are lacking. Captive breeding, or the management of grey duck populations on isolated islands appear the only feasible options. It seems unlikely that hybridisation can be reversed on the mainland, and a homogenous hybrid population is likely to eventually occupy the entire range of the grey duck across New Zealand.

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Lusimbo, Wanjala Simiyu. "Toxicity of Prudhoe Bay crude oil to mallard duck (Anas platyrhynchos) embryos". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0019/NQ43517.pdf.

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Kruse, Tamara. "Field Use of Alfaxalone and Potential Complications in Mallard Ducks (Anas platyrynchos)". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563491829618893.

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Libri sul tema "Mallard"

Hale, Don. Mallard. Long Preston, England: Dales, 2009.

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Beer, Amy-Jane. Mallard ducks. Danbury, Conn: Grolier, 2008.

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Mallard Fillmore--. Kansas City: Andrews and McMeel, 1995.

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Hédelin, Pascale. Face-to-face with the duck. Watertown, MA: Charlesbridge, 2005.

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Lipson, Joseph. On mallard feet: Poems. Toronto: A-Z Chapbooks, 2004.

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McIntosh, David. Mallard and the A4 class. Hersham: Ian Allan, 2008.

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Nichols, James D. Population ecology of the mallard. Washington, D.C: U.S. Dept. of the Interior, Fish and Wildlife Service, 1987.

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Mallard Fillmore-- on the stump. Kansas City, MO: Andrews and McMeel, 1995.

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Lawhead, Stephen. The tale of Timothy Mallard. Oxford: Lion, 1992.

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Lawhead, Stephen. The tale of Timothy Mallard. Oxford, England: Lion Pub., 1990.

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Più fonti

Capitoli di libri sul tema "Mallard"

Guillemain, Matthieu, Pär Söderquist, Jocelyn Champagnon e Johan Elmberg. "Mallard (Anas platyrhynchos Linnaeus, 1758)." In Invasive birds: global trends and impacts, 194–99. Wallingford: CABI, 2020. http://dx.doi.org/10.1079/9781789242065.0194.

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Abstract This chapter describes the common terminologies, taxonomy, morphology, geographical distribution, physiology, diet, behaviour, reproduction, habitats, ecology, invasion pathways, environmental impact, control and human use of the mallard (Anas platyrhynchos).

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Johannesen, Hege, e Claus Bech. "Respiratory Responses of the Mallard to External and Internal Cooling". In Physiology of Cold Adaptation in Birds, 173–78. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4757-0031-2_18.

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Nummi, P., H. Pöysä, J. Elmberg e K. Sjöberg. "Habitat distribution of the mallard in relation to vegetation structure, food, and population density". In Aquatic Birds in the Trophic Web of Lakes, 247–52. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1128-7_23.

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Lavretsky, Philip. "Population Genomics Provides Key Insights into Admixture, Speciation, and Evolution of Closely Related Ducks of the Mallard Complex". In Population Genomics, 295–330. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/13836_2020_76.

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Clemente, Tina S., e Chih-yu Shih. "Florencio Mallare". In China Studies in the Philippines, 193–200. Title: China studies in the Philippines : intellectual paths and the formation of a field / edited by Tina S. Clemente and Chih-yu Shih. Description: Abingdon, Oxon ; New York, NY: Routledge, 2019. | Series: Routledge contemporary China series ; 197: Routledge, 2018. http://dx.doi.org/10.4324/9780429508189-16.

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Leutner, Petra. "Stéphane Mallarmé". In Wege durch die Zeichen-Zone, 43–144. Stuttgart: J.B. Metzler, 1994. http://dx.doi.org/10.1007/978-3-476-03513-4_3.

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Pavelka, Margit, e Jürgen Roth. "Mallory Bodies". In Functional Ultrastructure, 152–53. Vienna: Springer Vienna, 2010. http://dx.doi.org/10.1007/978-3-211-99390-3_80.

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Wild, Gerhard. "Mallarmé, Stéphane". In Kindlers Literatur Lexikon (KLL), 1. Stuttgart: J.B. Metzler, 2020. http://dx.doi.org/10.1007/978-3-476-05728-0_12996-1.

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Trautner, Tamara. "Stéphane Mallarmé". In Kindler Kompakt Französische Literatur 19. Jahrhundert, 138–41. Stuttgart: J.B. Metzler, 2016. http://dx.doi.org/10.1007/978-3-476-05516-3_18.

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Testenoire, Pierre-Yves. "Saussure/Mallarmé". In Studies in the History of the Language Sciences, 129–42. Amsterdam: John Benjamins Publishing Company, 2020. http://dx.doi.org/10.1075/sihols.127.09tes.

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Atti di convegni sul tema "Mallard"

Watanabe, Takuma, Hirokazu Madokoro, Satoshi Yamamoto, Hanwool Woo e Kazuhito Sato. "Development of a Prototype Mobile Robot for Mallard Navigation". In 2019 19th International Conference on Control, Automation and Systems (ICCAS). IEEE, 2019. http://dx.doi.org/10.23919/iccas47443.2019.8971681.

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Hashimoto, Masumi, Hirokazu Madokoro, Kanji Watanabe, Masayuki Nishiguchi, Satoshi Yamamoto, Hanwool Woo e Kazuhito Sato. "Mallard Detection using Microphone Array and Delay-and-Sum Beamforming". In 2019 19th International Conference on Control, Automation and Systems (ICCAS). IEEE, 2019. http://dx.doi.org/10.23919/iccas47443.2019.8971736.

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Zhang, Xiong, e Philip J. Guo. "Mallard: Turn the Web into a Contextualized Prototyping Environment for Machine Learning". In UIST '19: The 32nd Annual ACM Symposium on User Interface Software and Technology. New York, NY, USA: ACM, 2019. http://dx.doi.org/10.1145/3332165.3347936.

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"Angiosuppressive and Teratogenic Influence of an Edible Medicinal herb, Insulin plant (Costus igneus) in Mallard Duck (Anas platyrhynchos) Embryos". In Multi-Disciplinary Manila (Philippines) Conferences Jan. 26-27, 2017 Cebu (Philippines). Universal Researchers (UAE), 2017. http://dx.doi.org/10.17758/uruae.ae0117303.

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Kanev, Svilen, Sam Likun Xi, Gu-Yeon Wei e David Brooks. "Mallacc". In ASPLOS '17: Architectural Support for Programming Languages and Operating Systems. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3037697.3037736.

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Pocock, Lynn, e Robert Mallary. "Dedication ---Robert Mallary, 1917--1997". In ACM SIGGRAPH 97 Visual Proceedings: The art and interdisciplinary programs of SIGGRAPH '97. New York, New York, USA: ACM Press, 1997. http://dx.doi.org/10.1145/259081.259166.

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Barahona Contreras, Andrés, e Cornelia Miller Granados. "Aplicaciones matemáticas para la elaboración de la malla de puntos para investigación en el territorio de Costa Rica". In I Congreso Internacional de Ciencias Exactas y Naturales. Universidad Nacional, 2019. http://dx.doi.org/10.15359/cicen.1.83.

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La utilización de sistemas de información geográfica (SIG) permite integrar, almacenar, editar, analizar, compartir y mostrar información georreferenciada. A nivel país es necesario contar con recursos estandarizados, como en el caso de sistemas de mallas de globales y discretas, que faciliten la interoperabilidad de la información que permita la gestión y sostenibilidad del territorio y los recursos naturales. La academia brinda aportes concretos en trabajos como la Malla de Inventario Forestal Nacional (IFN) y en esfuerzos interinstitucionales como los que se llevan a cabo en el Sistema Nacional De Monitoreo De Cobertura Y Uso De La Tierra Y Ecosistemas (SIMOCUTE). Además, el acercamiento a organizaciones internacionales como el Servicio Forestal de Estados Unidos (USFS) quien brindó el enfoque de utilización de mallas de puntos hexagonales que presentan una distribución equidistante y densificable de puntos. El análisis de la solución existente desde un enfoque de abstracción matemática y la aplicación de conceptos básicos ha permitido la automatización en la generación de mallas hexagonales que cumplen las condiciones de anidación, distribución y densificación; desde una construcción con comportamiento fractal de infinitos niveles no iterativos. El proceso de análisis desde conceptos básicos matemáticos permite formular una solución algorítmica implementable a nivel computacional optimizada, que brinda la posibilidad de generar una herramienta que sirva para distintas áreas de estudio que reflejen la información sobre el territorio.

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Li, Meng-Lin. "Adaptive photoacoustic imaging using the Mallart-Fink focusing factor". In Biomedical Optics (BiOS) 2008, a cura di Alexander A. Oraevsky e Lihong V. Wang. SPIE, 2008. http://dx.doi.org/10.1117/12.764317.

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Fahl, Sascha, Marian Harbach, Thomas Muders, Matthew Smith, Lars Baumgärtner e Bernd Freisleben. "Why eve and mallory love android". In the 2012 ACM conference. New York, New York, USA: ACM Press, 2012. http://dx.doi.org/10.1145/2382196.2382205.

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Zhao, Yingquan, Liuping Zhang, Jingjing Hu e Taiping Liao. "Mallat Wavelet Filter Coefficient Calculation". In 2013 Fifth International Conference on Computational and Information Sciences (ICCIS). IEEE, 2013. http://dx.doi.org/10.1109/iccis.2013.259.

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Rapporti di organizzazioni sul tema "Mallard"

Kodupuganti, Swapneel R., Sonu Mathew e Srinivas S. Pulugurtha. Modeling Operational Performance of Urban Roads with Heterogeneous Traffic Conditions. Mineta Transportation Institute, gennaio 2021. http://dx.doi.org/10.31979/mti.2021.1802.

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The rapid growth in population and related demand for travel during the past few decades has had a catalytic effect on traffic congestion, air quality, and safety in many urban areas. Transportation managers and planners have planned for new facilities to cater to the needs of users of alternative modes of transportation (e.g., public transportation, walking, and bicycling) over the next decade. However, there are no widely accepted methods, nor there is enough evidence to justify whether such plans are instrumental in improving mobility of the transportation system. Therefore, this project researches the operational performance of urban roads with heterogeneous traffic conditions to improve the mobility and reliability of people and goods. A 4-mile stretch of the Blue Line light rail transit (LRT) extension, which connects Old Concord Rd and the University of North Carolina at Charlotte’s main campus on N Tryon St in Charlotte, North Carolina, was considered for travel time reliability analysis. The influence of crosswalks, sidewalks, trails, greenways, on-street bicycle lanes, bus/LRT routes and stops/stations, and street network characteristics on travel time reliability were comprehensively considered from a multimodal perspective. Likewise, a 2.5-mile-long section of the Blue Line LRT extension, which connects University City Blvd and Mallard Creek Church Rd on N Tryon St in Charlotte, North Carolina, was considered for simulation-based operational analysis. Vissim traffic simulation software was used to compute and compare delay, queue length, and maximum queue length at nine intersections to evaluate the influence of vehicles, LRT, pedestrians, and bicyclists, individually and/or combined. The statistical significance of variations in travel time reliability were particularly less in the case of links on N Tryon St with the Blue Line LRT extension. However, a decrease in travel time reliability on some links was observed on the parallel route (I-85) and cross-streets. While a decrease in vehicle delay on northbound and southbound approaches of N Tryon St was observed in most cases after the LRT is in operation, the cross-streets of N Tryon St incurred a relatively higher increase in delay after the LRT is in operation. The current pedestrian and bicycling activity levels seemed insignificant to have an influence on vehicle delay at intersections. The methodological approaches from this research can be used to assess the performance of a transportation facility and identify remedial solutions from a multimodal perspective.

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Glinsky, Michael Edwin, Thomas Moore, William Lewis, Matthew Robert Weis, Christopher Ashley Jennings, David Ampleford, Eric Harding, Patrick Knapp, Matthew R. Gomez e Sophia Lussiez. Quantification of MagLIF Morphology using the Mallat Scattering Transformation. Office of Scientific and Technical Information (OSTI), ottobre 2019. http://dx.doi.org/10.2172/1569785.

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Shensa, M. J. Discrete Wavelet Transforms: The Relationship of the a Trous and Mallat Algorithms. Fort Belvoir, VA: Defense Technical Information Center, dicembre 1991. http://dx.doi.org/10.21236/ada244882.

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Howard, Joanna, Oluwafunmilayo Para-Mallam, Plangsat Bitrus Dayil e Philip Hayab. Vulnerability and Poverty During Covid-19: Religious Minorities in Nigeria. Institute of Development Studies (IDS), novembre 2021. http://dx.doi.org/10.19088/creid.2021.013.

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The Covid-19 pandemic has had direct and indirect effects on religiously marginalised groups, exacerbating existing inequities and undermining ambitions for those ‘furthest behind’ to be reached and supported through the Sustainable Development Goals (SDGs). The intersection of religious identity, socioeconomic status, geographic location, gender, and age compound vulnerability to violence and its impacts. This policy briefing, written by Dr Joanna Howard, Professor Oluwafunmilayo Para-Mallam, Dr Plangsat Bitrus Dayil, and Dr Philip Hayab, draws on research into the experiences of the pandemic by religious minorities living in Kaduna and Plateau states in Nigeria and finds that the pandemic deepened pre-existing ethno-religious fault lines. Exacerbated by ongoing insecurity, it contributed to increased poverty, with women particularly affected, and worsening mental health, with people experiencing fear, frustration, and depression. There are also long-term consequences for development; for example, on children’s education.

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Khalil, James, MaryAnne Iwara e Martine Zeuthen. Journeys through Extremism: The Experiences of Forced Recruits in Boko Haram. RESOLVE Network, settembre 2022. http://dx.doi.org/10.37805/cbags2022.2.

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This case study provides exploratory research into the personal journeys of forced recruits into Boko Haram, to examine how they entered the organization, the conditions they experienced in camps and settlements, their exits from the group, their subsequent experiences in state hands, and their perspectives about future reintegration. These themes are particularly pertinent given the mass disengagements from Boko Haram in spring 2022, and the extent to which federal and state systems lack the capacity to absorb and handle the large numbers involved. Research was undertaken at Operation Safe Corridor (OPSC), a program established in 2016 by the Nigerian state to provide an off-ramp for members of Boko Haram and Islamic State West Africa Province (ISWAP) deemed to be ‘low risk’ by military intelligence. Located at Mallam Sidi on the outskirts of Gombe, the OPSC program houses cohorts of around six hundred clients at any point in time. This report features the findings from thirteen in-depth interviews with participants in the OPSC program to provide important insights into the state-sponsored off-ramp from this group.

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Laverde Orozco, Alexander, e María del Pilar Romero Lozada. Diagnóstico del sistema de siembra en invernadero: Casa de malla- laterales abatibles del tomate chonto (Lycopersicon esculentum Mill) en el municipio de Restrepo – Valle del Cauca. Universidad Nacional Abierta y a Distancia, dicembre 2019. http://dx.doi.org/10.22490/ecapma.3415.

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Álvarez Zuluaga, Carlos Andrés, Claudia Espinal Correa, Jorge Humberto Rubio Elorza e Mauricio Vasco Ramírez. La simulación en salud: una estrategia de evaluación y formación por competencias. Ediciones Universidad Cooperativa de Colombia, novembre 2021. http://dx.doi.org/10.16925/wpgp.04.

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La simulación clínica no es una novedad. Hace ya mucho se distanció de sus orígenes en la aviación y colonizó áreas como la educación en salud. En este libro se la presenta como una tecnología que, acompañada de recursos como los simuladores y estrechamente ligada al campo de la pedagogía y la didáctica, la pone en un lugar privilegiado dentro de la compleja relación de enseñanza-aprendizaje, es decir, la convierte en una estrategia que contribuye al desarrollo y potenciamiento de las habilidades y destrezas requeridas por las disciplinas en las que se encuentra inmersa, a la vez que favorece la toma de decisiones del futuro profesional, en nuestro caso, del área de la salud. Parte de esto radica en que, una vez insertada en la malla curricular de los programas de educación superior, la simulación permite escalar varios grados de complejidad y situaciones: desde la adquisición de habilidades y destrezas básicas, hasta la compleja toma de decisiones cuya encrucijada pone en tela de juicio la vida de los pacientes. En nuestro caso, la simulación se sitúa bajo un modelo de educación por competencias, acorde con las modalidades y a los requisitos que demandan las instancias gubernamentales que regulan la educación superior que exigen evidencias de lo aprendido y, con ello, el papel de las prácticas académicas (indicadores) en ambientes adecuados. En ese escenario, la simulación da respuesta al profesional que se promete educar bajo una educación atenta a resultados del aprendizaje verificables.

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Geologic maps of the Big Mallard, Middle Bargamin, and Magruder additions to the Frank Church-River-of-No-Return Wilderness, Lemhi, and Idaho counties, Idaho. US Geological Survey, 1992. http://dx.doi.org/10.3133/mf2204.

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