Mallard/Mexican Duck (Anas platyrhynchos/diazi)

Drilling, Nancy; Titman, Rodger D.; McKinney, Frank

doi:10.2173/bna.658

Cited by 49 publications

(39 citation statements)

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“…published accounts (Johnsgard 2010, BirdLife International andNatureServe 2012), including the fact that highest densities are reported in the prairie-parkland region (Drilling et al 2002). As with other dabbling species, Mallard abundance was associated with amount of cropland, amount of shoreline, water body density, and CMI.…”

Section: Variablementioning

confidence: 94%

Models to predict the distribution and abundance of breeding ducks in Canada

Barker¹,

Cumming²,

Darveau³

2014

ACE

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ABSTRACT. Detailed knowledge of waterfowl abundance and distribution across Canada is lacking, which limits our ability to effectively conserve and manage their populations. We used 15 years of data from an aerial transect survey to model the abundance of 17 species or species groups of ducks within southern and boreal Canada. We included 78 climatic, hydrological, and landscape variables in Boosted Regression Tree models, allowing flexible response curves and multiway interactions among variables. We assessed predictive performance of the models using four metrics and calculated uncertainty as the coefficient of variation of predictions across 20 replicate models. Maps of predicted relative abundance were generated from resulting models, and they largely match spatial patterns evident in the transect data. We observed two main distribution patterns: a concentrated prairie-parkland distribution and a more dispersed pan-Canadian distribution. These patterns were congruent with the relative importance of predictor variables and model evaluation statistics among the two groups of distributions. Most species had a hydrological variable as the most important predictor, although the specific hydrological variable differed somewhat among species. In some cases, important variables had clear ecological interpretations, but in some instances, e.g., topographic roughness, they may simply reflect chance correlations between species distributions and environmental variables identified by the model-building process. Given the performance of our models, we suggest that the resulting prediction maps can be used in future research and to guide conservation activities, particularly within the bounds of the survey area. Des modèles pour prédire la répartition et l'abondance des canards nichant au CanadaRÉSUMÉ. Le manque de connaissances détaillées sur l'abondance et la répartition des espèces de sauvagine dans l'ensemble du Canada limite notre capacité à conserver et à gérer leurs populations de façon efficace. Au moyen de 15 années de données provenant d'inventaires aériens réalisés par transects, nous avons modélisé l'abondance de 17 espèces ou groupes d'espèces de canards dans les parties méridionale et boréale du Canada. Nous avons inclus 78 variables relatives au climat, à l'hydrologie et au paysage dans des modèles amplifiés d'arbres de régression, pour lesquels des courbes de réponse flexibles et les interactions multidimensionnelles entre les variables ont pu être examinées. Nous avons évalué la capacité de prédiction des modèles à l'aide de quatre paramètres et avons estimé l'incertitude en calculant le coefficient de variation des prédictions d'un jeu de 20 répétitions de modèles. Des cartes de l'abondance relative prédite ont été produites à partir des modèles et elles correspondent bien au profil spatial des données récoltées dans les transects. Nous avons observé deux tendances principales dans la répartition : l'une centrée sur les Prairies et les forêts-parcs, l'autre plus dispersée à la grandeur du Canada. Ces ten...

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Section: Variablementioning

confidence: 94%

Models to predict the distribution and abundance of breeding ducks in Canada

Barker¹,

Cumming²,

Darveau³

2014

ACE

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“…We assume these populations are present at the lake for a season of 105 days (mid-November to mid-March) (Baldassarre et al 2006), use Manny et al (1994) ) and assume that this rate scales allometrically across species by body mass (Nagy et al 1999). We use the following body masses: Tundra Swan, 6.75 kg (Limpert and Earnst 1994); Atlantic Canada Goose, 4.6 kg (Mowbray et al 2002); Snow Goose, 2.6 kg (Mowbray et al 2000); and Mallard mass for ducks, 1.2 kg (Drilling et al 2002). We assume waterfowl feces have an N content of 45 mg g −1 based on a data synthesis (Hahn et al 2007).…”

Section: Bird Transportmentioning

confidence: 99%

Waterfowl Impoundments as Sources of Nitrogen Pollution

Winton

Moorman

Richardson

2016

Water Air Soil Pollut

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Hydrologically controlled moist-soil impoundment wetlands provide critical habitat for high densities of migratory bird populations. Nutrients exported from heavily used impoundments by prescribed seasonal drawdown of surface water may contribute to the eutrophication of aquatic ecosystems. To investigate the relative importance of nutrient export from managed impoundment habitats, we conducted a field study at Mattamuskeet National Wildlife Refuge in North Carolina, USA, which contains 1545 ha of impoundments that drain into hypereutrophic Lake Mattamuskeet. We found that prescribed hydrologic drawdowns of an impoundment exported roughly the same amount of nitrogen (N) as adjacent fertilized agricultural fields on a per-area basis and contributed approximately one fifth of total N load to Lake Mattamuskeet. The prescribed drawdown regime, designed to maximize waterfowl production in impoundments, may be exacerbating the degradation of habitat quality in the downstream lake as an unintended consequence. Few studies of wetland N dynamics have targeted impoundments managed to provide wildlife habitat, but a similar phenomenon may occur in some of the 36,000 ha of similarly managed moist-soil impoundments on National Wildlife Refuges in the southeastern USA, especially those hosting dense concentrations of waterfowl. We suggest an earlier seasonal drawdown could potentially mitigate impoundment N pollution and estimate it could reduce N export from our study impoundment by more than 70 %.

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“…Therefore, we consider season-specific hatching rates in our model. Duck hatching rates are constant for a quarter of the year (during the hatching season) and zero otherwise [11,32]. The hatching season for ruddy turnstones is shorter, lasting for a tenth of a year [33].…”

Section: Seasonal Hatchingmentioning

confidence: 99%

“…The contact rate in duck species is assumed to be lower immediately before and at the start of the hatching season, when birds form mating pairs and become aggressive towards conspecifics (thereby interacting less than at other times during the year) [11,32]. Transmission among ruddy turnstones is assumed to be low all year except for when they are in Delaware Bay, where contact rates are greatly increased (based on density estimates [26]).…”

Section: Direct Transmissionmentioning

confidence: 99%

“…Many bird species are, to some degree, migrants, spending a portion of each year in locations that can be thousands of miles apart. Behaviour at different locations can also vary; mallards (Anas platyrhynchos), for example, are observed to be very territorial at their breeding grounds but social at other locations [11]. Despite the potential difficulties this spatial structure generates, migration routes for many species are well documented and can provide information on the timing and location of interspecific mixing [12].…”

Section: Introductionmentioning

confidence: 99%

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Dissecting a wildlife disease hotspot: the impact of multiple host species, environmental transmission and seasonality in migration, breeding and mortality

Brown

Drake

Stallknecht

et al. 2013

J. R. Soc. Interface.

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Avian influenza viruses (AIVs) have been implicated in all human influenza pandemics in recent history. Despite this, surprisingly little is known about the mechanisms underlying the maintenance and spread of these viruses in their natural bird reservoirs. Surveillance has identified an AIV 'hotspot' in shorebirds at Delaware Bay, in which prevalence is estimated to exceed other monitored sites by an order of magnitude. To better understand the factors that create an AIV hotspot, we developed and parametrized a mechanistic transmission model to study the simultaneous epizootiological impacts of multi-species transmission, seasonal breeding, host migration and mixed transmission routes. We scrutinized our model to examine the potential for an AIV hotspot to serve as a 'gateway' for the spread of novel viruses into North America. Our findings identify the conditions under which a novel influenza virus, if introduced into the system, could successfully invade and proliferate.

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Mallard/Mexican Duck (Anas platyrhynchos/diazi)

Cited by 49 publications

References 0 publications

Models to predict the distribution and abundance of breeding ducks in Canada

Models to predict the distribution and abundance of breeding ducks in Canada

Waterfowl Impoundments as Sources of Nitrogen Pollution

Dissecting a wildlife disease hotspot: the impact of multiple host species, environmental transmission and seasonality in migration, breeding and mortality

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