Masked oar duck
| Masked oar duck | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Male of the masked owl ( Nomonyx dominica ) in magnificent dress |
||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name of the genus | ||||||||||
| Nomonyx | ||||||||||
| Ridgway , 1880 | ||||||||||
| Scientific name of the species | ||||||||||
| Nomonyx dominica | ||||||||||
| ( Linnaeus , 1766) |
The masked oar duck ( Nomonyx dominica ), also known as the West Indian masked duck, is a species of bird in the subfamily of oar ducks and the only species of the genus Nomonyx . Occasionally it is placed in the genus Oxyura . As far as we know today, the masked rowing duck developed from an ancestor of the rowing ducks. It is the smallest of the rowing ducks and the only one that has a white wing field. Little is known about the way of life of this duck.
description
Masked owls are small ducks. Your body length is 34 centimeters. They have an average wing length of 14.5 centimeters (males) and 14.2 centimeters (females). The average weight is 406 grams for males and 339 grams for females.
The males of the masked owl have a striking black face mask in their magnificent dress. The beak is bright blue. The rump plumage is bright red-brown. The females resemble the other rowing ducks in their inconspicuous plumage; They can be distinguished by their particularly strong facial stripes and a white wing field. The beak is dark gray in them, towards the base it is slightly bluish. It lives very hidden and often makes its way through small aisles in the reed beds to the water. As a result, their feathers wear off very strongly on the tail, so that this often consists of no more than a bald shaft.
Masked oars, like swimming ducks, fly straight up from the water and thus differ from other oar ducks. Similar to this, however, it is able to set up the tail feathers stiffly. However, it usually swims with its tail feathers lying flat on the water.
Distribution, habitat and way of life
The main distribution area of the masked oar reaches from Mexico to Central America to South America. Masked owls are usually resident birds; Odd visitors can occasionally be seen in the extreme south of the USA. It was first seen in the United States in 1870. Since then, it has appeared sporadically in southwest Texas. Their habitat are flat, extensive subtropical and tropical swamps with heavy vegetation. Because of its inaccessible habitat, little is known about the species. Since they have not been kept in human care for a long time either, there is no evidence of their detention. However, the species was included in a study of sexual selection in which the reproductive organs of 16 ducks were compared. Masked owls had both the longest vagina and one of the longest penises compared to the other species .
Masked owls have only been observed in pairs or in small groups of up to 20 individuals. The nests were found in the reeds on Bülten or in dense clumps of rice. They were built in such a way that the ducks could dive into the water immediately in case of danger. Masked owls breeding in Texas begin the breeding season in November. In regions with highly seasonal rainfall, it coincides with the beginning of the rainy season. According to the current state of knowledge, only the female looks after the chicks. The incubation period is around 28 days.
Masked owls mainly eat seeds, roots and leaves of aquatic plants. The food is taken in by diving, grounding and being seen from the surface.
The species is not classified as endangered by the IUCN .
Individual references, literature and web links
Individual evidence
- ↑ Livezey (1986), McKracken et al. (1999)
- ↑ Alderfer, p. 40
- ↑ Kolbe, p. 75
- ↑ Gooders and Boyder, p. 167
- ↑ Alderfer, p. 40
- ↑ Gooders and Boyder, p. 166
- ↑ Kolbe, p. 76
- ↑ Patricia LR Brennan, Richard O. Prum, Kevin G. McCracken, Michael D. Sorenson, Robert E. Wilson, Tim R. Birkhead: Coevolution of Male and Female Genital Morphology in Waterfowl. PLoS ONE 2 (5): e418. doi : 10.1371 / journal.pone.0000418 , published online May 2, 2007
literature
- Jonathan Alderfer (Ed.): Complete Birds of North America , National Geographic, Washington DC 2006, ISBN 0-7922-4175-4
- T. Bartlett: Ducks And Geese - A Guide To Management. The Crowood Press, 2002, ISBN 1-85223-650-7
- John Gooders and Trevor Boyer: Ducks of Britain and the Northern Hemisphere , Dragon's World Ltd, Surrey 1986, ISBN 1-85028-022-3
- Hartmut Kolbe: The world's ducks. Ulmer Verlag 1999, ISBN 3-8001-7442-1
- Josep del Hoyo ; Andrew Elliott & Jordi Sargatal (Eds.): Handbook of Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona 1992, ISBN 84-87334-10-5 .
- Bradley C. Livezey: A phylogenetic analysis of recent anseriform genera using morphological characters. Auk 103 (4): 737-754. PDF in English
