| White-tailed Ptarmigan | |
|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Galliformes |
| Family: | Phasianidae |
| Subfamily: | Tetraoninae |
| Genus: | Lagopus |
| Species: | L. leucura |
| Binomial name | |
| Lagopus leucura (Richardson, 1831) |
|
| Synonyms | |
|
Lagopus leucurus (lapsus, see below) |
|
The White-tailed Ptarmigan, Lagopus leucura, is the smallest bird in the grouse family. It is found in the mountains of the western United States, Canada and Alaska.
Contents |
The White-tailed Ptarmigan is the smallest of the ptarmigans and the smallest bird in the grouse family. Adults are 11.8 to 12.2 inches (30 to 31 cm) long, with the males being only slightly larger than the females. The average weight is 11.6 to 16.9 ounces (330 to 480 g).[2] In the winter, this bird displays white plumage, while it appears grayish brown and speckled during the summer months. [3] Both sexes maintain white tail and wing feathers year-round, and males are identified by reddish eyecombs year-round. [4] http://worldbirdinfo.net/Pages/BirdMediaView.aspx [5]
The White-tailed Ptarmigan is the only bird to permanently reside in the alpine zone. [6] This zone includes rocky areas, krummholz, snowfields, and meadows. [7]
The White-tailed Ptarmigan is an alpine species, a permanent resident of the high mountains above timber line. It occupies open country and flies a great deal more than forest grouse, but still prefers running to flying. It ranges from Alaska and western Canada south to northern New Mexico.
The White-tailed Ptarmigan has been introduced into the Sierra Nevada Mountains of California, Wallowa Mountains in Oregon, and Uinta Mountains of Utah.[8][9] Males return from their timberline wintering areas to establish territories on spruce-willow timberline breeding grounds in April. Females arrive in early May and pairs are formed.
This herbivorous bird's diet varies seasonally. Nitrogen-rich snow buttercup leaves are favored in the spring season, while willow catkins, alpine avens flowers, and chickweed blooms form the majority of the ptarmigan's diet in the summer. [10] Once fall and winter arrive to the region, the ptarmigan prefers seeds, willow buds, and willow twigs. Winter food sources have a much higher cellulose content than summer forage, so the ptarmigan relies on bacteria-aided digestion in the cecum to extract essential nutrients. [11]
Ptarmigan chicks begin their lives eating insects. Once the chicks' digestive tracts and ceca are more fully developed, their diets shift to one of flowers and leaves. [12] Hens choose foraging patches where plant species containing proteins are abundant. The hens call their chicks to these plants, which are critical for the growth and development of the chicks. This suggests that the hens' food calls assist in enhancing survival rates of juvenile ptarmigans. [13]
The White-tailed Ptarmigan nests in shallow depressions in snow-free areas. These areas, generally protected from wind, are softened with grasses and a few feathers. One side of the nest is generally left open as an escape route. [14]
Males are usually monogamous and remain with the same mate for one breeding season. To attract females, a male will strut and display his tail feathers. [15] The female builds a simple scrape nest on the ground, while the male acts as a sentry to guard the nest. [16]
A clutch consists of 2-8 eggs, which retain a cinnamon color for most of the gestational period, but develop brown spots just prior to hatching. [17] http://www.pbase.com/image/126655318 [18] The precocial young leave the nest 6 to 12 hours after hatching. [19] Males remain with the females until the eggs hatch, which spans the incubation period of about 23 days. Juvenile ptarmigans remain with the mother through the autumn season. [20]
The White-tailed Ptarmigan has feathers located on its feet to serve as protection from the extreme cold often experienced in the alpine tundra environment. [21] In addition, these birds have feathers around their nostrils to warm the air prior to entry into the respiratory tract. [22] The most obvious adaptation is this bird's cryptic coloration, which enables it to blend in with its environment and avoid predation. [23] http://www.hancockwildlife.org/forum/viewtopic.php?showtopic=1276&page=69 [24] To conserve energy during the winter months, the ptarmigan avoids flight and roosts in snowbanks. During the summer, the ptarmigan eats grit to assist in digesting plant material. [25]
This bird serves as an indicator species for the alpine tundra, and denotes overall ecosystem health. Currently, this bird is not a conservation concern and is abundant in alpine zones across North America, indicating that this region is not undergoing dramatic climatic, temperature, or precipitation shifts. [26] The lack of overgrazing due to cattle, the lack of human development in alpine zones, and the laws regarding hunting bag limits allow the White-tailed Ptarmigan to thrive. [27]
The Ptarmigan's genus name, Lagopus, is derived from Ancient Greek lagos (λαγως), meaning "hare", + pous (πους), "foot", in reference to the bird's feathered legs (see also Snowshoe Hare). The species name leucura was for a long time misspelt leucurus, 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 leucura is correct.[28] The species name leucura is derived from the Latinized version of the Greek leukos, meaning "white", + oura, meaning "tail"., in reference to the bird's white tail year around.[29]