[order] ANSERIFORMES | [family] Anatidae | [latin] Anas gracilis | [authority] Buller, 1869 | [UK] Grey Teal | [FR] Sarcelle australasienne | [DE] Grauente | [ES] Cerceta Australiana | [NL] Grijze Witkeeltaling
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. 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. 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.
The Grey Teal is almost all grey-brown. Each feather of the body is edged with buff, except on the rump. The chin and throat are white, the bill is dark green and the eye is red. The secondary wing feathers have glossy blue-black patch, broadly bordered and tipped with white. In flight, a large white wedge is visible on the underwing. The Grey Teal is one of the smaller Australian ducks (males are larger than females). Both sexes are similar in plumage.
Listen to the sound of Grey Teal
Copyright remark: Most sounds derived from xeno-canto
recorded by Daniel Lane
Australasia : widespread. New Guinea to New Caledonia and Australia to New Zealand.
Grey Teals are common in all sheltered watered areas. These include fresh, brackish and salt water, and the birds can be found on the smallest area of water in the driest of areas. The most favoured habitat type is timbered pools and river systems of the inland areas, where these birds can be found in quite large numbers
Grey Teals may breed when there is available food and waterways are suitable. Taking advantage of this opportunistic breeding style, birds lay soon after suitable conditions arrive and may raise several broods while the conditions remain favourable. If conditions are not suitable, birds may not breed at all in a year. Most breeding takes place around inland waterways, and nests may be placed on the ground, in rabbit burrows or in tree hollows. The birds normally lay their eggs on the bare floor of the nest site, which are then covered with down (feathers). The incubation lasts for about 4 weeks, clutch size ranges from 4-14 eggs (usually 7-8). The chicks fledge after about 8 weeks.
Grey Teals feed in small to large flocks. Food consists of a variety of types and includes dry land plants, aquatic plants, seeds, crustaceans, and insects and their larvae. Feeding methods are also varied. Birds may dabble (filter surface water or mud through the bill), upend and feed from the bottom, or graze from the surface of the water on plant material.
copyright: Josep del Hoyo
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.
Mostly sedentary but wanders extensively during the dry season. In this period they might spread across the whole of the continent.