Mallard (Anas platyrhynchos) Science Article 10 abstract Mallard (Anas platyrhynchos) breeding densities in the prairie pothole habitat of eastern North Dakota during 1961-1980 varied from 2.28 birds/km2 in 1977 to 9.47 birds/km2 in 1963 and were correlated with pond abundance (r = 0.543, P < 0.05). The number of basins used by pairs declined with […]
Category: Anseriformes
Forced copulation in captive mallards (Anas platyrhynchos): II. temporal factors
Mallard (Anas platyrhynchos) Science Article 12 abstract A study of temporal trends in forced copulation was conducted in flight-pens with eight pairs of captive mallards to test the hypothesis that forced copulation is an evolved breeding strategy in waterfowl. Cheng, K. M.; Burns, J. T.; McKinney, F., Animal Behaviour 30:695-699 Download article download full text […]
Male and female reproductive tactics in mallards (anas platyrhynchos l.): sperm competition and cryptic female choice
Mallard (Anas platyrhynchos) Science Article 7 abstract Mallards, Anas platyrhynchos, are among the most common waterfowl species in theNorthern Hemisphere. Despite their abundance and despite growing interest of behavioralecologists and evolutionary biologists in key aspects of their behavior, few studies haveused genetic tools to investigate their mating system. We studied the breeding biology ofmallards by […]
A Comparison of Two Methods to Establish the Prevalence of Lead Shot Ingestion in Mallards (Anas platyrhynchos) from The Netherlands
Mallard (Anas platyrhynchos) Science Article 3 abstract Two collection methods for screening the mallard (Anas platyrhynchos) population in the Netherlands for the ingestion of spent lead shot were compared. One method consisted of examination of gizzards from mallards shot by hunters (n 2,859) and the other method consisted of examination of gizzards from mallards caught […]
Month to month changes in age ratio and brood size in Pink-footed Geese Anser brachyrhynchus in autumn
Pink-footed Goose (Anser brachyrhynchus) Science Article 7 abstract The conservation and management of wild goose populations requires an accurate estimate of productivity to be made each year, usually soon after the birds’ arrival in the wintering grounds. The best time to make the estimates is not always clear, however, since the measures used may vary […]
Month to month changes in age ratio and brood size in Pink-footed Geese Anser brachyrhynchus in autumn
Pink-footed Goose (Anser brachyrhynchus) Science Article 7 abstract The conservation and management of wild goose populations requires an accurate estimate of productivity to be made each year, usually soon after the birds’ arrival in the wintering grounds. The best time to make the estimates is not always clear, however, since the measures used may vary […]
Characterization of Northern pintail ( Anas acuta) ejaculate and the effect of sperm preservation on fertility
Northern Pintail (Anas acuta) Science Article 1 abstract Northern pintail duck semen and sperm traits were characterized, and the fertility of cold-stored spermatozoa was investigated using artificial insemination. Excellent qualityejaculates containing high proportions of motile spermatozoa were collected from drakes within 20 s by a massage technique. Semen was collected in Beltsville poultry semen extender, […]
Estimation of carcass fat and protein in northern pintails ( Anas acuta) during spring migration
Northern Pintail (Anas acuta) Science Article 2 abstract Foraging in stopover areas influences nutritional condition of birds during spring migration. Our purpose was to determine if body mass, percent carcass water, and serum biochemistry would predict energy reserves (carcass fat and protein) in northern pintails (Anas acuta) at a spring staging area, Lake St. Pierre […]
Parasites of waterfowl from southwest texas: ii. the shoveler, Anas clypeata
Northern Shoveler (Anas clypeata) Science Article 1 abstract Thirty-eight shoveler ducks, Anas clypeata, were collected in the Rio Grande Valley, Hudspeth County, Texas. Nineteen species of helminths, six species of lice and a sarcosporidian, Sancocystis nileyi, were recorded. Seventeen of the nineteen species of helminths were observed in fall migrants and twelve species were recorded […]
International Single Species Action Planfor the Conservation of the Light-bellied Brent Goose(East Canadian High Arctic population)(Branta bernicla hrota)
Light-bellied Brent Goose (Branta bernicla) Science Article 1 abstract The East Canadian High Arctic (ECHA) Light-bellied Brent Goose Branta bernicla hrota breedsin Canada’s eastern Queen Elizabeth Islands with the great majority wintering on the coastline of theisland of Ireland and smaller numbers on the Channel Islands and the northern coasts of France andSpain. It is […]