Chile teal
| Chile teal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chile teal ( Anas flavirostris ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Anas flavirostris | ||||||||||||
| Vieillot , 1816 |
The Chile teal or Andean duck ( Anas flavirostris ) is a South American species of duck of the genus Anas , which is also found on some sub-Antarctic islands. It is a small duck bird with a short neck. In large parts of its distribution area it is the smallest species of duck. Although it is hunted in most of its range, it is not considered a shy species.
There are four subspecies for this species, some of which have clear morphological differences. The genetic information of all Chile teals is very similar to that of Anas crecca carolinensis .
features
Adult Chile teals are around 35 to 45 centimeters long and weigh 600 to 830 grams. The male is on average 35 grams heavier than the female. The species has no seasonal dimorphism. The sexual dimorphism is only very slight. Females can be identified by the fact that the sides of the body appear scaly rather than spotted. The beak is also not as bright yellow in the females.
The beak sides are yellow with a darker beak ridge. The iris is brown, the legs are gray. The plumage of a chile teal is light gray-brown with black flecks on the nape of the neck ; the upper parts are dark gray-brown with lighter edges, while the underside and torso and tail are pale blue-gray with black spots on the chest. The wings are also gray-brown. Young birds are grayer and less spotted. Newly hatched birds, on the other hand, have a dark brown back with yellow marking on the wing, the underside and face are yellow.
There is a clear difference in voices between the sexes. Males have the characteristic teal whistle, while the females croak nasally.
The chicks are generally quite dark. On their upper side they are black-brown. The chicks have black-brown streaked eyes and cheeks on their faces. The face and chest, on the other hand, are rich yellow-brown. The ventral side and a narrow band along the back are yellowish olive brown. The chick's beak and feet are dark gray. The chicks of the individual subspecies look basically the same, but they vary in color intensity. The chicks of the white-winged duck ( A. f. Oxyptera ) are significantly lighter.
Subspecies and occurrences
_RWD.jpg)
Well-known subspecies are:
- The Andean teal ( A. f. Andium ) - lives in Colombia (central and eastern Andes ), northwest Venezuela and Ecuador .
- The nominate form ( A. f. Flavirostris ), also known as a subspecies as Chile teal, lives in the Peruvian Andes, western and central Bolivia , northern Chile , northern Argentina and in the Chilean and Argentinian flatlands as far as Tierra del Fuego. Other areas of distribution are Uruguay , the Falkland Islands and South Georgia . The nominate form is overwintered in Paraguay and southern Brazil . The small population in Cumberland Bay of South Georgia, which was only discovered in 1971 and comprised 40 to 50 ducks by the end of the 20th century, may be traced back to Chile teals, which were naturalized here by whalers. Presumably this population was discovered so late because it was previously confused with the similar pointed-tailed duck. It is not known whether the Chile teals that occur on Bird Island , a small island off the west coast of South Georgia, descended from the ducks of Cumberland Bay or whether the population descended from South American random visitors.
- The Merida teal ( A. f. Altipetens ) - inhabits the eastern Andes from Colombia to northwestern Venezuela .
- The white-winged duck ( A. f. Oxyptera ) - lives in the Andes from central Peru to north-western Argentina. They are generally a bit smaller than their relatives. It is larger and lighter than the nominate form. Her dark brown shoulder feathers are broadly lined with light. The body is almost monochrome light gray, while the chest is only sparsely spotted. The beak is a little longer and brighter than the nominate form.
habitat
The Chile teal lives in the Andes at an altitude of 2600 to 4300 meters above sea level. Freshwater lakes, ponds , rivers, marshes and wooded swamps are preferred. In winter it lives mainly in coastal areas. It is a widespread species in the Falkland Islands that occurs at significantly lower latitudes.
nutrition
Adult birds feed primarily on invertebrates such as insects , crustaceans and amphipods , as well as seeds from plants. In winter they make way for dead seaweed . Newborn animals feed on small crustaceans, amphipods and mosquito larvae .
behavior
Adult Chile teals hunt in shallow water by digging or diving. Another strategy is to filter mud on the bank of a body of water. The birds are usually found in groups of up to twenty individuals. Outside the breeding season, larger clusters can also be found, especially during the moulting period . Occasionally they are found together with the cinnamon . Couples are likely to bond permanently or semi-permanently. The activity patterns of the Chile teal consist of standing in groups on the bank, flying low over the surface in the event of disturbances, or sitting on tall trees.
Reproduction
The mating season varies depending on the distribution; in Colombia it begins in February / March, in Venezuela in August, from Peru to northern Argentina in November / December and further south from late August to September. The nests are built alone or in loose groups and are brooded by the female. When rearing the brood , it is supported by the male. The nest itself is preferably built close to the water, in dense vegetation , in large forks or under house roofs. A female lays around five to eight eggs per clutch, which weigh 39 grams and are 57 by 37 millimeters in size. The surface is cream-colored. The breeding season lasts about 24 to 26 days, and the young are fledged after six to seven weeks. Sexual maturity is reached at the age of one year.
Hazard and protection
The animals are generally not endangered; locally they can usually be found in large numbers. However, some subspecies are declining. The dangers are development pressure and hunting .
supporting documents
literature
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds. Volume 1: Ratites to Ducks. Oxford University Press, Oxford 1990, ISBN 0-19-553068-3 .
- Janet Kear (Ed.): Ducks, Geese and Swans. Oxford University Press, 2005, ISBN 0-19-854645-9 .
- Hartmut Kolbe; Die Entenvögel der Welt , Ulmer Verlag 1999, ISBN 3-8001-7442-1
- Hadoram Shirihai: A Complete Guide to Antarctic Wildlife - The Birds and Marine Mammals of the Antarctic Continent and Southern Ocean , Alula Press, Degerby 2002, ISBN 951-98947-0-5
- Robin and Anne Woods: Atlas of Breeding Birds of the Falkland Islands , Anthony Nelson, Shorpshire 1997, ISBN 0-904614-60-3
Web links
- Photos and detailed data
- Videos, photos and sound recordings on Anas flavirostris in the Internet Bird Collection
- Anas flavirostris inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2013. Retrieved February 2, 2014.