[order] ANSERIFORMES | [family] Anatidae | [latin] Anas castanea | [authority] Eyton, 1838 | [UK] Chestnut Teal | [FR] Sarcelle rousse | [DE] Kastanienente | [ES] Cerceta Castana | [NL] Kastanjetaling
| Genus |
Species |
subspecies |
Region |
Range |
| Anas |
castanea |
|
AU |
Australia |
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.
The Chestnut Teal is a small dabbling duck with a high forehead and rounded head. Males are distinctive, having a glossy green head, chestnut brown neck, breast and flanks, dark brown upper body and wings, and a black undertail with contrasting white patch. Females are mottled dark brown and grey, with a pale throat streaked brown and a dark eye stripe. In both sexes the eye is a deep red, the bill is blue-grey and the legs and feet are green-grey. The wings have a dark glossy green to purple speculum (panel) edged white and the underwing is brown, with white wing pits.
| wingspan min.: |
0 |
cm |
wingspan max.: |
0 |
cm |
| size min.: |
35 |
cm |
size max.: |
46 |
cm |
| incubation min.: |
23 |
days |
incubation max.: |
29 |
days |
| fledging min.: |
53 |
days |
fledging max.: |
60 |
days |
| broods: |
1 |
|
eggs min.: |
7 |
|
| |
|
|
eggs max.: |
10 |
|
Australasia : Australia. The Chestnut Teal is found in south-western and south-eastern Australia. In the east, it is found from Rockhampton, Queensland to Ceduna, South Australia, being most common in New South Wales, Victoria and Tasmania. It is also a vagrant to New Guinea and Lord Howe Island
The Chestnut Teal is found on wetlands and estuaries in coastal regions, and is one of the few ducks able to tolerate high salinity waters, although it still needs fresh water for drinking. It will also use open freshwater lakes, reservoirs and sewage ponds during dry seasons. It mainly breeds in coastal areas, needing hollow trees in water or short grasslands near water for nesting, and it will readily take to suitable nest boxes.
Chestnut Teals form monogamous pairs that stay together outside the breeding season. Both parents choose and defend a nest site and the males stay with the female while she incubates the eggs. The nest is usually located over water, in a down-lined tree hollow about 6 m to 10 m high. Sometimes nests are placed on the ground, among clumps of grass near water, and are little more than a scrape, lined with down. Artificial nest boxes of the right size and located in suitable habitat will also be readily used. Males do not assist with incubation but do look after the young when hatched. Sometimes ‘dump-laying’ occurs, where females leave their eggs in the nest of another female, which accounts for some large clutch sizes (up to 17 eggs in a nest). The young hatch ready to swim and walk within a day, and will move out with their mother onto the water straight away. Both parents defend their brood and will chase off other teal with pecks. If threatened by a predator, parents will feign injury, splash and quack in an attempt to distract it while the young dive or swim off.
The Chestnut Teal eats seeds and insects, along with some vegetation, as well as molluscs and crustaceans in more coastal habitats. It mainly feeds at the water’s edge during the rising tide, dabbling at food items being washed in. It also dabbles for food while swimming in the water, up-ends to bottom feed or takes food from the surface.
httpv://www.youtube.com/watch?v=x9mdGck-5Yc
copyright: Stephen Wallace
This species has a very 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). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very 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 with movements between breeding and non-breeding areas, but many birds do not disperse over great dinstances
