«

»

Nov 15 2011

Print this Post

Eatons Pintail (Anas eatoni)

Eatons Pintail

[order] ANSERIFORMES | [family] Anatidae | [latin] Anas eatoni | [authority] Sharpe, 1875 | [UK] Eatons Pintail | [FR] Canard d’Eaton | [DE] sudl. Spiessente | [ES] anade de Eaton | [NL] Eaton-Pijlstaart

Subspecies

Monotypic species

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

Small, short-necked pintail. Resembles female Northern Pintail A. acuta, but darker overall tone, more reddish-brown, and scalloping on flanks smaller and less obvious. Male has elongated central tail feathers and green speculum bordered with white. Minority of males (1%) assume brighter breeding plumage with trace of chocolate-brown on head and whitish stripe up side of neck. Female has brown speculum bordered with white. Subspecies similar but drygalskii slightly paler, more buff on breast, and some birds show fine vermiculations on lower hindneck and flanks


wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 40 cm size max.: 45 cm
incubation min.: 22 days incubation max.: 24 days
fledging min.: 40 days fledging max.: 45 days
broods: 1   eggs min.: 6  
      eggs max.: 12  

Range

Indian Ocean : Kerguelen Islands

Habitat

It occupies small freshwater lakes, as well as pools, marshes, peatbogs and streams, being more frequent on the coast in winter where it is found in coastal lagoons, along the sea shore and especially in sheltered bays

Reproduction

Outside the breeding season, it occurs in small parties, occasionally in concentrations of up to 200 birds on Kerguelen. The breeding season is from November to the end of January or February and clutch size is a minimum of five. Possibly extended pair bonds.

Feeding habits

It feeds on vegetation, insects and crustaceans

Conservation

It is projected that this species could undergo a rapid decline in the near future, owing to predation by feral cats, and it therefore qualifies as Vulnerable.
It was formerly much hunted by sealers and scientific expeditions, with 200-300 shot each year after the establishment of a base in 1950. Today, introduced predators are the greatest threat on Possession, Cochons Island (Crozet) and the Kerguelen Islands. On Kerguelen, feral cats may prove to be a serious threat in the near future if petrels, their staple prey, reach low levels. The birds introduced to Amsterdam probably disappeared owing to predation by feral cats and brown rat Rattus norvegicus.
Eatons Pintail status Vulnerable

Migration

Sedentary

Distribution map

Eatons Pintail distribution range map

Print Friendly
Print Print

About the author

admin

Permanent link to this article: http://www.planetofbirds.com/anseriformes-anatidae-eatons-pintail-anas-eatoni

Leave a Reply