_Lagopus_, VIEILLOT, Analyse, 1816. (Type, _Tetrao lagopus_, L.)
GEN. CHAR. Nasal groove densely clothed with feathers. Tail of sixteen
or eighteen feathers. Legs closely feathered to the claws. The northern
species snow white in winter.
The Ptarmigans inhabit the northern regions of both hemispheres, and
with the Arctic fox and hares, the lemmings, and a few other species,
characterize the Arctic zone. They are of rare occurrence within the
limits of the United States, though farther north they become abundant.
The species all change to white in winter, except _L. scoticus_, which
appears to be merely a permanently dark, southern, insular form of _L.
albus_. (See Alfred Newton in Proceedings of the Philadelphia Academy,
July, 1871, pp. 96, 97.)
Species and Varieties.
=A.= Tail-feathers always with more or less black.
1. =L. mutus.= Bill small, slender, the length from the nasal groove
to the tip decidedly more than the height through the base. Male in
winter with a black stripe on the lores.
♂ in summer with uniform black feathers on the breast; autumnal
plumage bluish-gray, mottled. _Hab._ Northern Europe …
var. _mutus_.
♂ in summer without uniform black feathers on the breast. Autumnal
plumage orange-rufous. _Hab._ Northern North America; Greenland;
Iceland …
var. _rupestris_.
2. =L. albus.= Bill large, stout; the length from the nasal groove
less, or not more, than the height through the base. Male in winter
without black stripe on lores. _Hab._ Northern Europe and northern
North America.
=B.= Tail-feathers entirely pure white.
3. =L. leucurus.= Winter plumage wholly white. _Hab._ Alpine
summits of the Western mountain-ranges, from Colorado to Oregon and
Washington, and north into British America.
[Plate: PLATE LXII.
1. Lagopus albus. ♂ _Summer._ Alaska, 21462.
2. Lagopus albus. ♀ _Summer._ Labrador, 43468.
3. Lagopus albus. ♂ _Winter._
4. Lagopus rupestris. ♂ _Winter._ 30370.
5. Lagopus rupestris. ♀ _Summer._ Labrador, 44582.
6. Lagopus leucurus. ♂ _Summer._ Colorado, 16002.]
Lagopus albus, AUD.