Willow ptarmigan a range of lower plant species. It is also believed that the greening of parts of the Arctic is affecting Willow Ptarmigan populations by altering the shape and size of the shrubs they are able to feed on. Male willow ptarmigans are territorial birds. Males arrive in the breeding areas and set up territories in April and May, aggressively defending them against male interlopers. When the females arrive a few weeks later, the male performs courtship displays such as aerial manoeuvres, strutting and tail-fanning. When she has chosen a mate and a nesting site, the female lays a clutch of
Ptarmigan Pass (Sawatch Range) Ptarmigan Pass (Sawatch Range) Ptarmigan Pass (elevation 11,765 ft) is a high mountain pass in the Rocky Mountains of central Colorado in the United States. It is located on the crest of the northern end of the Sawatch Range, along the border of Eagle and Summit counties, south of Vail Pass. The pass is traversed by a jeep trail that is passable by four-wheel drive vehicles and on foot. 2WD vehicles will only make it to the summit from the west; the east side is rocky and boggy at times. The trail connects Interstate 70 east of Vail Pass with