The pygmy geese are a group of very small “perching ducks” in the genus Nettapus which breed in the Old World tropics. They are the smallest of all wildfowl. As the “perching ducks” are a paraphyletic group, they need to be placed elsewhere. The initially assumed relationship with the dabbling duck subfamily Anatinae has been questioned, and it appears they form a lineage in an ancient Gondwanan radiation of waterfowl, within which they are of unclear affinities. An undescribed fossil species from the late Hemphillian (5.0-4.1 mya) of Jalisco, central Mexico, has also been identified from the distal end of a tarsometatarsus. It is only record of the genus in the New World.
Physical charateristics
The Cotton Pygmy-goose is a tiny duck with a small, dark, goose-like bill. The male has a white head, neck and underparts with a glossy green back that appears black in dull light. In breeding season, the male has a black band around the base of the neck. The female is predominately brown with darker plumage on the wings. Both sexes have dark plumage on the forehead and crown.
Copyright remark: Most sounds derived from xeno-canto
wingspan min.:
0
cm
wingspan max.:
0
cm
size min.:
31
cm
size max.:
38
cm
incubation min.:
0
days
incubation max.:
0
days
fledging min.:
0
days
fledging max.:
0
days
broods:
1
eggs min.:
6
eggs max.:
16
Range
Oriental Region : widespread. Pakistan, India, Bangladesh, southeast Asia and south to northern Australia.
Habitat
The Cotton Pygmy-goose is an almost entirely aquatic species. Preferred habitat is deep freshwater lagoons, swamps and dams, particularly those with waterlilies or other floating vegetation, such as hydrilla, ceratophyllum, vallisneria, najas, lemna and chara. The species tends to avoid running water where deep?water vegetation cannot grow. The species requires dead trees with hollows near water for nesting and roosting sites. Grazing may benefit the species by reducing the number of dense reeds and encouraging the growth of open diverse freshwater aquatic emergents.
Reproduction
The species is likely to be monogamous with clutch sizes thought to range from 6 to 16. The nest is a natural hollow in a tree-trunk standing in or near water, sometimes lined with grass, rubbish and feathers The type of parental care is unknown.
Feeding habits
The Cotton Pygmy-goose feeds almost entirely on aquatic vegetation, particularly hydrilla and Pondweed. Foraging is undertaken by dabbling and picking at the water surface or by stripping seeds and flowers from aquatic plants. Individuals flatten their head and neck on the water surface and rapidly filter water through their bill while swimming fast, swallowing food with an upward jerk of the head. Aquatic insects are also eaten.
Video Cotton Pygmy Goose
httpv://www.youtube.com/watch?v=ZCHp6ZEakB0
copyright: Tom Tarrant
Conservation
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). The population trend appears to be fluctuating, 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. The overall population trend is fluctuating, although some populations are stable and others have unknown trends
Migration
It is largely resident, apart from dispersion in the wet season, but Chinese birds winter further south.
