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The avian family Anatidae, commonly called waterfowl, comprise the ducks, geese, and swans.The International Ornithological Committee (IOC) recognizes these 174 Anatidae species distributed among 53 genera, 32 of which have only one species.
Measuring the culmen. The upper margin of the beak or bill is referred to as the culmen.The measurement is taken using calipers with one jaw at the tip of the upper mandible and the other at the base of the bill (at the junction with the skull, a measurement called "total culmen") or where the feathers begin (a measurement called "exposed culmen").
Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Non-migratory birds are said to be resident or sedentary. Approximately 1,800 of the world's 10,000 bird species are long-distance migrants. [14] [15]
This is a list of the breeds of domestic duck which have official recognition at national or international level. [1]Most breeds of duck derive from the wild mallard, Anas platyrhynchos, while a small minority are descendants of the Muscovy duck, Cairina moschata.
Pteronetta, Hartlaub's duck – traditionally dabbling ducks, but may be closer to Cyanochen; Cairina and Asarcornis, Muscovy duck and white-winged duck, respectively (2 species) – traditionally dabbling ducks, but may be paraphyletic, with one species in Tadorninae and the other closer to diving ducks
The only ducks which are similar are the greater scaup and lesser scaup, but these species have no tuft and a different call. The tufted duck is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds applies. [11] Refer to the following table for measurements of the tufted duck: [12]
During nesting season, the female lays a clutch of 7–12 eggs with each of them measuring 4.9–6 cm (1.9–2.4 in) in length and 3.4–4.4 cm (1.3–1.7 in) in width. Incubation lasts for 24–27 days and the nestlings leave after around 1–2 days. A gadwall can only raise one brood a season [2]
The brown teal (Anas chlorotis; Māori: pāteke) is a species of dabbling duck of the genus Anas native to New Zealand. For many years it had been considered to be conspecific with the flightless Auckland and Campbell teals in Anas aucklandica; the name "brown teal" has also been largely applied to that entire taxon.