Snow Goose (Anser caerulescens) Science Article 1 abstract Geese are large, herbivorous birds that graze in huge flocks in ways that may have a considerable impact onvegetation. This is exemplified best in two subspecies of snow geese, the lesser and the greater, both of which have increaseddramatically in numbers in recent decades. In arctic coastal […]
Category: Anseriformes
Aktivitatsrhythmus von Brandgansen (Tadorna tadorna) und Watvogeln (Charadrii) an der Nordseekiiste
Shelduck (Tadorna tadorna) Science Article 1 abstract Shelducks, Oystercatchers, Grey Plovers, Knots, Dunlins, Bar-tailed Godwits, Curlews, Spotted Redshanks, Redshanks, and Greenshanks showed a tidal rhythm of time-activity budgets on the Wadden Sea coast during the non-breeding season. Ringed Plovers and Ruffs did not react to the tidal rhythm. Night-time feeding could be observed in most […]
Timing of moult in male and female Shelducks Tadorna tadorna: Effects of androgens and mates
Shelduck (Tadorna tadorna) Science Article 2 abstract We investigated effects of testosterone treatment on timing and rate of moult of wing-feathers in male Shelducks Tadorna tadorna, and whether this treatment influences the timing of moult in untreated females. Three experimental treatments were conducted, each with two groups of sexual inactive male Shelducks, which were kept […]
Conservation of the globally threatened white-headed duck,Oxyura leucocephala, in the face of hybridization with the NorthAmerican ruddy duck, Oxyura jamaicensis: results of a control trial
Ruddy Duck (Oxyura jamaicensis) Science Article 1 abstract The North American ruddy duck, introduced into Europe in the 1960s, threatens the globally endangered whiteheadedduck with extinction through hybridization. A regional control trial, conducted in three areas of Britain, killed over 2,600birds and led to a significant regional reduction in ruddy duck numbers. Control using firearms […]
Record of a Redhead, Aythya americana, laying eggs in a Northern Harrier, Circus cyaneus, nest
Redhead (Aythya americana) Science Article 5 abstract Alberta; Anatidae; Aythya americana; Circus; Circus hudsonius; egg; egg description; eggs; laying; nest; nest parasitism; Northern Harrier Fleskes,J. P, Canadian Field-Naturalist 106:263-264. Download article download full text (pdf)
SALT GLAND DEVELOPMENT IN MIGRATORY REDHEADS(AYTHYA AMERICANA) IN SALINE ENVIRONMENTS ON THEWINTER RANGE, GULF OF MEXICO, USA
Redhead (Aythya americana) Science Article 3 abstract Redheads (Aythya americana) migrate annually from their breeding range in the interior ofNorth America to winter along the coasts of the United States and Mexico. Two of the mostimportant areas where redheads traditionally concentrate in winter are the Laguna Madre andnearby bays in southern Texas and the Chandeleur […]
Survey for Blood Parasites in Redheads (Aythya americana) Wintering at the Chandeleur Islands, Louisiana
Redhead (Aythya americana) Science Article 1 abstract We detected no infections with species of Plasmodium, Haemoproteus, Leucocytozoon,Sarcocystis or Trypanosoma in blood smears, liver and spleen impressions, and muscle tissue from 136 redheads (Aythya americana) collected or captured at the ChandeleurIslands, Louisiana (USA), during three winters (1987 to 1990). Thomas C. Michot, Journal of Wildlife Diseases, […]
Wetland Salinity and Salt Gland Size in the Redhead Aythya americana
Redhead (Aythya americana) Science Article 4 abstract Numerous investigators have shown experimentally that nasal or supraorbital salt glands exist in nonmarine waterfowl and have the ability to enlarge or atrophyi n responset o changesin the salt content of the drinking water (Scothome 1959, Ellis et al. 1963, Cooch 1964, Benson and Phillips 1964, Schmidt-Nielsen and […]
FOOD HABITS OF REDHEADS (AYTHYA AMERICANA) WINTERING IN SEAGRASS BEDS OF COASTAL LOUISIANA AND TEXAS, USA
Redhead (Aythya americana) Science Article 2 abstract Diets of wintering redheads (Aythya americana) have been studied in the past, but none of theprevious studies compared diets of the upper gastrointestinal tract to determine if they differeddue to sex, age, location, year, or time of year. MICHOT, T. C et al, Acta Zoologica Academiae Scientiarum Hungaricae […]
Intersexual differences in feeding ecology in a male dominated wintering Pochard Aythya ferina population.
Pochard (Aythya ferina) Science Article 1 abstract Intersexual differences in feeding rates, aggression rates, an d feeding site selection were investi gated in a flock of up to 2700 Pochard Aythya ferina wintering at Salford docks, Greater M anchester (239 males per 100 females) . As often found elsewhere, females were less aggressive than males, […]