| Snow partridge | |
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| Snow Partridge fromKedarnath Wildlife Sanctuary | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Galliformes |
| Family: | Phasianidae |
| Subfamily: | Phasianinae |
| Genus: | Lerwa Hodgson, 1837 |
| Species: | L. lerwa |
| Binomial name | |
| Lerwa lerwa | |
| Synonyms | |
Lerwa nivicola | |
Thesnow partridge (Lerwa lerwa) is agamebird in the pheasant familyPhasianidae found widely distributed across the high-altitudeHimalayan regions ofPakistan,China,India andNepal. It is theonly species within its genus, and is thought to be the mostbasal member of the "erectile clade" of the subfamilyPhasianinae. The species is found inalpine pastures and open hillside above thetreeline but not in as bare rocky terrain as theHimalayan snowcock and is not as wary as that species. Males and females look similar inplumage but males have a spur on theirtarsus.
This partridge appears grey above and chestnut below with bright redbill and legs and the upperparts finely barred in black and white. In flight the pattern of dark brownprimaries and secondaries with a narrow trailing white margin make them somewhat like the much largerTibetan snowcock. The 14-feathered tail is dark and barred in white. There is variation in the shade and some birds have a nearly black crown.[3] The primaries and secondaries are brown and the breast is deep chestnut. The abdomen has more white and the lower flanks and feathers around the vent are barred brown and white. The under-tail coverts are chestnut with black shaft streaks and white tips. Young birds have the lower parts mottled and the barring less distinct. The tarsus is feathered on the front of the leg half-way to the toes.[4][5][6]
It measures 38–40 cm in length. Females weigh 450–580 g; males, 550–700 g. Sexes are similar in plumage, female lacks spurs on the tarsus while the male has a blunt spur and sometimes a second incipient spur. Downy chicks have a resemblance to the chicks of theblood pheasant.[7] Chicks are born with the tarsi feathered and the nostril opening is covered by feathers.[8]
This species was first described byBrian Houghton Hodgson in 1833 and given the genus nameLerwa based on theBhutia name for it in Nepal.[9][10] Hodgson initially placed it in the genusPerdix calling itPerdix lerwa.[11] A subspecies,L. l. major was described byRichard Meinertzhagen fromSichuan whileL. l. callipygia from south Kansu was noted by Stegmann in 1938, but these are not usually recognized.[12][13][14] The species has been retained in this monotypic genus due to various peculiarities including the tarsus feathering and the lack of clear sexual dimorphism in plumage.[7] A species of bird louse,Chelopistes lervicola has been described as an ectoparasite of this species, and other species in this louse genus are known to parasitize the Cracidae, Meleagrididae and Odontophorinae of the New World.[15]
Snow partridge is found in theHimalayas fromPakistan toArunachal Pradesh along the higher ranges, mainly 3000 to 5000 m (rarely below 2000 m) altitude. It is found above the tree line but not on as bare and stony terrain as the snowcocks.[12] Although said to be found inAfghanistan, there is no evidence.[3] The species is found over a large area is generally considered to be of low conservation concern. It is hunted to some extent, due to its habit of being more approachable than snowcock and has declined in population in some areas.[7]
The usual habitat is alpine pastures, open grassy hillsides with grass,lichens,moss,ferns andrhododendrons. Is found among small snow-patches but not in as stony or bare ground as the snowcock. The birds however are very local in their distribution.[3][7][8]
The snow partridge is found is small groups, usually about 6 to 8 but up to 30 during the non-breeding season. When flushed, they usually fly up before scattering away with noisy wing beats. The flight is rapid and stirring. It has a habit of sunning itself on rocks during the midday.[3] The call in the breeding season is said to resemble that of thegrey francolin of the plains.[7] It has been compared in habit to that of the ptarmigan. It is said to feed on mosses, lichens, berries, and the shoots of plants. It also swallows grit to aid digestion.[10][16][17]
The breeding season is May to July. The males are believed to be monogynous. The nest is a scrape on a hill-side under some sheltering rock, either scratched out by themselves or already available, and usually hidden with vegetation.[10] The nest is sometimes lined with moss but well concealed although given away by the male. About 3 to 5 eggs, pale yellow in color and slightly glossy with reddish-brown markings on the rounded end,[10] are laid, and the female incubates while the male stands sentinel. Parent birds may usedistraction displays to draw the attention of predators. They call in a comparatively softer lower note to the young, which respond with chicken-likecheep calls.[18][19][20][21]
Apart fromChelopistes lervicola described as an ectoparasite of this species, anArgasid tickArgas himalayensis has been noted.[22][23]
Genera oflandfowl and their extinct allies | |||||||||||||||||||||||||||||||||||
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