Tag: all of Anas

Movements of a nomadic waterfowl, Grey Teal Anas gracilis, across inland Australia ? results from satellite telemetry spanning fifteen months

Grey Teal (Anas gracilis) Science Article 1 abstract We used lightweight satellite transmitters to follow the movements of 17 Grey Teal Anas gracilis between September 2003 and November 2004 in two contrasting landscapes, the agricultural districts of southern Australia and the desert landscapes of the interior. Roshier D.A., Klomp N.I. and Asmus M., Ardea 94(3): […]

A tangled tale of two teal: population history of the grey Anas gracilis and chestnut teal A. castanea of Australia

Grey Teal (Anas gracilis) Science Article 2 abstract Two Australian species of teal (Anseriformes: Anatidae: Anas), the grey teal Anas gracilis and the chestnut teal A. castanea, are remarkable for the zero or near-zero divergence recorded between them in earlier surveys of mitochondrial DNA (mtDNA) diversity. We confirmed this result through wider geographical and population […]

A tangled tale of two teal: population history of the chestnut teal Anas castanea and grey teal Anas gracilis of Australia

Chestnut Teal (Anas castanea) Science Article 1 abstract Two Australian species of teal (Anseriformes: Anatidae: Anas), the grey teal Anas gracilis and the chestnut teal A. castanea, are remarkable for the zero or near-zero divergence recorded between them in earlier surveys of mitochondrial DNA (mtDNA) diversity. We confirmed this result through wider geographical and population […]

Variation of pecking rate with sward height in wild wigeon Anas penelope

Wigeon (Anas penelope) Science Article 2 abstract We examined how pecking rate changed with sward height in wintering European wigeon Anas penelope in a nature reserve of the French Atlantic coast. Pecking rates were recorded as the time taken to perform 10 or 50 pecks. We found a negative correlation between pecking rate and sward […]

Feeding behaviour of breeding Wigeon Anas penelope in relation to seasonal emergence and swarming behaviour of chironomids.

Wigeon (Anas penelope) Science Article 3 abstract Emergence of chironomids started in mid-April, and reached a peak at the end of April and in the beginning of May. Most ‘spring’ chironomids emerged around noon, whereas the majority of chironomids emerging later in the season, appeared at night. In general, there was a positive correlation between […]

Constraints of feeding on Salicornia ramosissimaby wigeonAnas penelope: an experimental approach

Wigeon (Anas penelope) Science Article 1 abstract The coastal marshes of the Charente-Maritime (western France) are a major wintering area for wigeon Anas penelope. In these marshes, wigeon feed mainly on grasses, while foraging on Salicornia (a .eshy, succulent halophyte) is uncommon. In order to understand the reason for this under-exploitation, an experimental study was […]

On the eclipse plumage of the mallard (Anas platyrhyncha platyrhyncha)

Mallard (Anas platyrhynchos) Science Article 4 abstract It is a peculiarity of most species of ducks that in the early summer, shortly after the breeding season, the males moult and then assume a plumage which in coloration and form closely resembles that of the female. This is known as the ‘eclipse’ or ‘summer ‘ plumage. […]

Prior knowledge about spatial pattern affects patch assessment rather than movement between patches in tactile-feeding mallard

Mallard (Anas platyrhynchos) Science Article 9 abstract Heterogeneity in food abundance allows a forager to concentrate foraging effort in patches that are rich in food. This might be problematic when food is cryptic, as the content of patches is unknown prior to foraging. In such case knowledge about the spatial pattern in the distribution of […]

Pair formation among experimentally introduced mallards Anas platyrhynchos reflects habitat quality

Mallard (Anas platyrhynchos) Science Article 1 abstract Using data from two independent field experiments, we address whether pair formation in introduced mallards Anas platyrhynchos is associated with habitat quality, specifically food limitation at the brood stage. Based on the concentration of total phosphorous in the water, the study lakes were divided into two groups, poor’ […]