Tuesday, May 15, 2012

>Anas clypeata (Northern Shoveler)

Northern Shoveler





Northern Shoveler
Male
Female
Conservation status
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Anseriformes
Family:Anatidae
Subfamily:Anatinae
Genus:Anas (disputed)
Species:A. clypeata
Binomial name
Anas clypeata
Linnaeus, 1758
European distribution. Light green: summer only. Blue: winter only. Dark green: all-year.
Synonyms
Spatula clypeata (but see text)
The Northern Shoveler (play /ˈʃʌvələr/Anas clypeata), Northern Shoveller in British English, sometimes known simply as the Shoveler, is a common and widespread duck. It breeds in northern areas of Europe and Asia and across most of North America,wintering in southern Europe, Africa, the Indian subcontinent, Southeast Asia, and Central and northern South America. It is a rare vagrant to Australia. In North America, it breeds along the southern edge of Hudson Bay  and west of this body of water, and as far south as the Great Lakes west to Colorado, Nevada, and Oregon.
The Northern Shoveler is sometimes referred to by hunters as the "spoony". Other disparaging names, as compared to the mallard, are the "smiling mallard" and the "Poor Man's Mallard".
The Northern Shoveler is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. The conservation status of this bird is Least Concern.

Taxonomy

This species was described by Linnaeus in his Systema naturae in 1758 under its current scientific name. Usually placed in Anas like most dabbling ducks, it stands well apart from such species as the Mallard and together with the other shovelers and their relatives forms a "blue-winged" group that may warrant separation as genus Spatula.
No living subspecies are accepted today. Fossil bones of a very similar duck have been found in Early Pleistocene deposits at Dursunlu, Turkey. It is unresolved, however, how these birds were related to the Northern Shoveler of today; i.e., whether the differences noted were due to being a related species or paleosubspecies, or attributable to individual variation.


Description


Northern Shoveler in Brazoria National Wildlife Refuge

Female stretching after bathing in Kolkata
This species is unmistakable in the northern hemisphere due to its large spatulate bill. The breeding drake has an iridescent dark green head,white breast and chestnut belly and flanks. In flight, pale blue forewing feathers are revealed, separated from the green speculum by a white border. In early fall the male will have a white crescent on each side of the face. In non-breeding (eclipse) plumage, the drake resembles the female.
The female is a drab mottled brown like other dabblers, with plumage much like a female Mallard, but easily distinguished by the long broad bill, which is gray tinged with orange on cutting edge and lower mandible.The female's forewing is gray.
They are 19 inches (48 cm) long and have a wingspan of 30 inches (76 cm) with a weight of 600 grams (1.3 lb).


Behavior


In flight
Northern Shovelers feed by dabbling for plant food, often by swinging its bill from side to side and using the bill to strain food from the water. They use their highly specialized bill (from which their name is derived) to forage for aquatic invertebrates – a carnivorous diet. Their wide-flat bill is equipped with well-developed lamellae – small, comb-like structures on the edge of the bill that act like sieves, allowing the birds to skim crustaceans and plankton from the water's surface. This adaptation, more specialized in shovelers, gives them an advantage over other puddle ducks, with which they do not have to compete for food resources during most of the year. Thus, mud-bottomed marshes rich in invertebrate life are their habitat of choices.
The shoveler prefers to nest in grassy areas away from open water. Their nest is a shallow depression on the ground, lined with plant material and down. Hens typically lay about nine eggs. The drakes are very territorial during breeding season and will defend their territory and partners from competing males. Drakes also engage in elaborate courtship behaviors, both on the water and in the air; it is not uncommon for a dozen or more males to pursue a single hen. Despite their stout appearance, shovelers are nimble fliers.
This is a fairly quiet species. The male has a clunking call, whereas the female has a Mallard-like quack.


Habitat and range

This is a bird of open wetlands, such as wet grassland or marshes with some emergent vegetation.
This bird winters in southern EuropeAfrica, the Indian Subcontinent, northern South America, and the Malay Archipelago. Those wintering in the Indian Subcontinent make the taxing journey over the Himalayas, often taking a break in wetlands just south of the Himalaya before continuing further south to warmer regions. In North America it winters south of a line from Washington to Idaho and from New Mexico east to Kentucky, also along the Eastern Seaboard as far north as Massachusetts. In the British Isles, home to more than 20% of the North Western European population, it is best known as a winter visitor, although it is more frequently seen in southern and eastern England, especially around the Ouse Washes, the Humber and the North Kent Marshes, and in much smaller numbers in Scotland and western parts of England. In winter, breeding birds move south, and are replaced by an influx of continental birds from further north. It breeds across most of Ireland, but in very small numbers.
This dabbling duck is strongly migratory and winters further south than its breeding range (so far so that there have been four reports in Australia). It is not as gregarious as some dabbling ducks outside the breeding season and tends to form only small flocks. Among North America's duck species, northern shovelers trail only mallards and blue-winged teal in overall abundance. Their populations have been healthy since the 1960s, and have soared in recent years to more than 4 million birds (2011), most likely because of favorable breeding, migration, and wintering habitat conditions.


Gallery



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