Northern Shoveler (Anas clypeata)

Northern Shoveler

Subspecies

Genus	Species	subspecies	Region	Range
Anas	clypeata		NA, EU	widespread

Genus

Anas is a genus of dabbling ducks. It includes mallards, wigeons, teals, pintails and shovelers in a number of subgenera. Some authorities prefer to elevate the subgenera to genus rank.[1] Indeed, as the moa-nalos are very close to this clade and may have evolved later than some of these lineages, it is rather the absence of a thorough review than lack of necessity that this genus is rather over-lumped. The phylogeny of this genus is one of the most confounded ones of all living birds. Research is hampered by the fact the radiation of the two major groups of Anas ? the teals and mallard groups ? took place in a very short time and fairly recently, roughly in the mid-late Pleistocene. Furthermore, hybridization may have long played a major role in Anas evolution, with within-subgenus hybrids regularly and between-subgenus hybrids not infrequently being fully fertile.[1] The relationships between species are much obscured by this fact, and mtDNA sequence data is of dubious value in resolving their relationships; on the other hand, nuclear DNA sequences evolve too slowly to resolve the phylogeny of the subgenus Anas for example. Some major clades can be discerned. For example, that the traditional subgenus Anas, the mallard group, forms a monophyletic (in the loose sense, i.e. non-holophyletic) group has never been seriously questioned by modern science and is as good as confirmed (but see below). On the other hand, the phylogeny of the teals is very confusing. For these reasons, the dabbling duck lineages more distantly related to mallard group (which includes the type species of Anas) than the wigeons should arguably be separated in their own genera. These would include the Baikal Teal, the Garganey, the spotted black-capped Punanetta group, and the shovelers and other blue-winged species. Whether the wigeons, which are very distinct in morphology and behavior, but much less so in mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequences, should also be considered a distinct genus Mareca (including the Gadwall and Falcated Duck) is essentially the one remaining point of dispute as regards the question which taxa should remain in this genus and which ones should not.

Physical charateristics

The very large, spatulate bill is the most distinguishing feature of the aptly named Northern Shoveler. The male in breeding plumage has bright wings, a bright iridescent-green head with a yellow eye, bold white breast, and chestnut sides. Females, juveniles, and males in eclipse plumage (from May through August) are mottled brown with orange legs and a green-black iridescent speculum with a blue patch on the forewing.
Northern Shovelers rarely tip up, but filter mud through their bills, swimming with their heads outstretched, bills skimming the water’s surface, sifting out food. In flight they stay in tight bunches, weaving to and fro like shorebirds. Shovelers are very territorial, and pair bonds remain intact through incubation, unlike most other species of ducks.

Listen to the sound of Northern Shoveler

[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Northern Shoveler.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.:	73	cm	wingspan max.:	82	cm
size min.:	44	cm	size max.:	52	cm
incubation min.:	22	days	incubation max.:	23	days
fledging min.:	40	days	fledging max.:	23	days
broods:	1		eggs min.:	7
			eggs max.:	12

Range

North America, Eurasia : widespread

Habitat

Northern Shovelers inhabit shallow, marshy ponds and wetlands at low elevations. Breeding habitat is in open country (prairie or tundra), or lowland woodlands and clearings, always near shallow water. During winter and migration they will use virtually any wetland as long as it has muddy edges. Shovelers will forage in sewage ponds and stagnant or polluted waters avoided by other species of ducks.

Reproduction

Pair formation begins in the winter and continues during spring migration. Males remain with the females through the incubation period. The female chooses the site (generally in short grass). She builds the nest, a shallow depression made of grass and weeds, lined with down, and incubates the 9 to 12 eggs for 23 to 28 days by herself. A few hours after they hatch, the female leads the young to the water where they can swim and forage immediately. The young typically stay close to the cover of emergent vegetation, and the female tends them until they fledge at 52 to 66 days of age.

Feeding habits

The bill of the Shoveler is ideally suited for straining small swimming invertebrates from the water and mud. Seeds and aquatic plants are also important food items, especially during winter

Video Northern Shoveler

httpv://www.youtube.com/watch?v=Kus43uwfTsY

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Anas clypeata is widespread breeder across much of Europe, which accounts for less
than a quarter of its global breeding range. Its European breeding population is
large (>170,000 pairs), and was stable between 1970-1990. Although no trend data
were available for the stronghold in Russia during 1990-2000, several countries-
notably the Netherlands-suffered marked declines, and the species probably
underwent a moderate decline (>10%) overall.
This duck inhabits North America and northern Eurasia. For practical reasons its populations of the European Union can be subdivided in two distinct sub-populations, separated by their wintering quarters. The first, totalling about 40000 individuals and apparently stable, is wintering in the Atlantic regions from Denmark to the British Isles and Aquitaine. The second population is estimated at 450000 individuals, but its current trends are unknown. It winters in the Black Sea region, the Mediterranean and West Africa.

Migration

Mostly migratory, breeders of Iceland all migrate, probably to Ireland or Britain. Most British breeders move southwards to south France, south Spain, north and central Italy, a few to North Africa. Bulk have left Britain by end October, before main arrivals of Continental birds. Breeders from south Fenno-Scandia and Russia east to and south migrate west and south-west to western seaboard, chiefly Netherlands, Britain, and Ireland, some going further to west and south France and north Spain. Populations of east Russia, Trans-Urals, and west Siberia migrate south through Volga region, then to south Caspian, Azov and Black Seas, and to Mediterranean, particularly Turkey, Greece, Italy, and North Africa, where overlap with north European breeders. Those wintering from Egypt south to East Africa presumably also from Russia. Main autumn migration rather earlier than other Palearctic ducks, except Garganey. Principal passage across Europe in September-October, with major passage through Britain in November. Departs tropical Africa in February, peak movement through Europe mid-March to mid-April, and virtually all breeders returned by early May.

Distribution map

Northern Shoveler distribution range map

Literature

Title Parasites of waterfowl from southwest texas: ii. the shoveler, Anas clypeata

Author(s): Dorothy Broderson, Albert G. Canaris, and John R. Bristol

Abstract: Thirty-eight shoveler ducks, Anas clypeata, were c..[more]..

Source: Journal of Wildlife Diseases Vol. 13, October, 1977

download full text (pdf)

Planet of Birds