|A pair in spring plumage in Norway|
some 20-30, including:
The Rock Ptarmigan (Lagopus muta) is a medium-sized gamebird in the grouse family. It is known simply as Ptarmigan in UK English and colloquially as Snow Chicken or Partridge in North America, where it is the official bird for the territory of Nunavut, Canada, and the official game bird for the province of Newfoundland and Labrador, Canada.
The Rock Ptarmigan is 34–36 centimetres (13–14 in) long (tail 8 cm) with a wing-span of 54–60 centimetres (21–24 in). It is slighter smaller than the Willow Ptarmigan by about 10%. The male's "song" is a loud croaking.
The Rock Ptarmigan is seasonally camouflaged; its feathers moult from white in winter to brown in spring or summer. The breeding male has greyish upper parts with white wings and under parts. In winter, its plumage becomes completely white except for the black tail. It can be distinguished from the winter Willow Ptarmigan (Willow Ptarmigan in North America) by habitat—the Rock Ptarmigan prefers higher elevations and more barren habitat; it is also smaller with a more delicate bill.
Habitat and range 
The Rock Ptarmigan is a sedentary species which breeds across arctic and subarctic Eurasia and North America (including Greenland) on rocky mountainsides and tundra. It is widespread in the Arctic Cordillera and is found in isolated populations in the mountains of Scotland, the Pyrenees, the Alps, Bulgaria, the Urals, the Pamir Mountains, the Altay Mountains, and Japan. Because of the remote habitat in which it lives, it has only a few predators—such as Golden Eagles—and it can be surprisingly approachable.
The small population living on Franz Josef Land in the Russian High Arctic, overwinters during the polar night, and survives by feeding on rich vegetation on and underneath high cliffs where seabird colonies are located in summer 
The Rock Ptarmigan feeds primarily on birch and willow buds and catkins when available. It will also eat various seeds, leaves, flowers and berries of other plant species. Insects are eaten by the developing young.
Apart from the comb, the male Rock Ptarmigan has no ornaments or displays that are typical for grouses in temperate regions. Studies on other grouses have shown that much variation in comb size and colour exists between the species, and that the comb is used in courtship display and aggressive interactions between males. Many studies have shown that there is a strong correlation between the comb size and the level of testosterone in males; one report from 1981 showed that the amount of testosterone is correlated to aggressiveness against other males.
The male's comb has been the focus of studies regarding sexual selection. Studies of a population of male Rock Ptarmigans in Scarpa Lake, Nunavut, have shown that during the first year, mating success among males was influenced by comb size and condition, and bigamous males had larger combs than monogamous males. The correlation to size disappeared after the first year, but the correlation to comb condition remained. This is consistent with another study of the same population of L. muta that showed that mating success overall is correlated to comb condition. Exceptions were first-time breeders, in which the size of the comb influenced mating success.
The species name, muta, comes from New Latin and means "mute", referring to the simple croaking song of the male. It was for a long time misspelt mutus, in the erroneous belief that the ending of Lagopus denotes masculine gender. However, as the Ancient Greek term λαγωπους is of feminine gender, and the species name has to agree with that, the feminine muta is correct.
The word ptarmigan comes from the Scottish Gaelic tàrmachan, literally croaker. The silent initial p was added in 1684 by Robert Sibbald through the influence of Greek, especially pteron (πτερον), "wing", "feather" or "pinion".
In culture 
Rock Ptarmigan meat is a popular part of festive meals in Icelandic cuisine. Hunting of Rock Ptarmigans was banned in Iceland in 2003 and 2004 due to its declining population. Hunting has been allowed again since 2005, but is restricted to November and only for personal consumption, i.e. selling Rock Ptarmigan is illegal.
In Thomas Bewick's A History of British Birds (1797) the species is named as "White Grouse" with alternatives "White Game, or Ptarmigan". The birds feed, records Bewick, "on the wild productions of the hills, which sometimes give the flesh a bitter, but not unpalatable taste: it is dark coloured, and has somewhat the flavour of the hare."
Rock Ptarmigan in Mount Arakawa, mother and child
Rock Ptarmigan in Akaishi Mountains, winter plumage
Lagopus Muta Iceland Snæfellsnes April 2012
- BirdLife International (2004). Lagopus muta. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006.
- Government of Nunavut. "The Rock Ptarmigan (LAGOPUS MUTUS) Official Bird of Nunavut". Retrieved 2010-12-04.
- The Birds of the Western Palearctic [Abridged]. OUP. 1997. ISBN 0-19-854099-X.
- Dinets, V. (2001) Winter ecology of Willow Ptarmigan Lagopus lagopus and Rock Ptarmigan L. mutus at the northern limit of their range. Ornitologia 29: 326-327 (in Russian with English summary).
- Tomek, Teresa & Bocheński, Zygmunt (2005): Weichselian and Holocene bird remains from Komarowa Cave, Central Poland. Acta zoologica cracoviensia 48A(1-2): 43-65. PDF fulltext
- Johnsgard, P. A. (1984), Grouse of the world, Lincoln: University of Nebraska Press, ISBN 0-8032-2558-X.
- Hjorth, I. (1970), "Reproductive behaviour in Tetraonidae", Viltrevy 7: 183–596.
- Stokkan, K. A. (1979a), "Testosterone and daylength-dependent development of comb size and breeding plumage of male willow ptarmigan (Lagopus lagopus lagopus)", The Auk 96 (1): 106–115.
- Wattson, A. & Parr, R. (1981), "Hormone implants affecting territory size and aggressive and sexual behaviour in red grouse", Ornis Scandinavica 12 (1): 55–61.
- Brodsky, L. M. (1988), "Mating tactics of male rock ptarmigan, Lagopus mutus: a conditional mating strategy", Animal Behaviour 36 (2): 335–342, doi:10.1016/S0003-3472(88)80003-4.
- Holder, K. & Montgomerie, R. (1993), "Context and consequences of comb displays by male rock ptarmigan", Animal Behaviour 45 (3): 457–470, doi:10.1006/anbe.1993.1057.
- Jobling, James A (1991). A Dictionary of Scientific Bird Names. OUP. ISBN 0-19-854634-3.
- David, Normand & Gosselin, Michel (2002): The grammatical gender of avian genera. Bull. B. O. C. 122(4): 257-282.
- Lockwood, W B (1993). The Oxford Dictionary of British Bird Names. OUP. ISBN 978-0-19-866196-2.
- Bewick, Thomas; Beilby, Ralph (1797). "White Grouse". A History of British Birds, Volume 1: Land Birds. Beilby and Bewick.
|Wikimedia Commons has media related to: Lagopus muta|
|Wikispecies has information related to: Lagopus muta|
- Stamps: Rock Ptarmigan (worldwide); with world RangeMap
- Ptarmigan videos, photos & sounds on the Internet Bird Collection
- Ptarmigan RSPB
- Rock Ptarmigan-Lagopus muta photo gallery VIREO
- Lagopus muta in the Flickr: Field Guide Birds of the World
- Lagopus muta on Avibase