Willow ptarmigan

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Willow ptarmigan
Lagopus lagopus - adult (Denali, 2010).jpg
Adult Alaskan willow ptarmigan (L. l. alascensis) in summer plumage,
Denali National Park
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Galliformes
Family: Phasianidae
Genus: Lagopus
Species:
L. lagopus
Binomial name
Lagopus lagopus
Willow Ptarmigan Lagopus lagopus distribution map.png
Willow Grouse range [2]
Synonyms

Lagopus albus
Lagopus mediusWoldřich, 1893
Tetrao lagopusLinnaeus, 1758

The willow ptarmigan ( /ˈtɑːrmɪɡən/ ) (Lagopus lagopus) is a bird in the grouse subfamily Tetraoninae of the pheasant family Phasianidae. It is also known as the willow grouse and in Ireland and Britain, where the subspecies L. l. scotica was previously considered to be a separate species, as the red grouse. It breeds in birch and other forests and moorlands in northern Europe, the tundra of Scandinavia, Siberia, Alaska and Canada, in particular in the provinces of Newfoundland and Labrador and Quebec. It is the state bird of Alaska. In the summer the birds are largely brown, with dappled plumage, but in the winter they are white with some black feathers in their tails (British populations do not adopt a winter plumage). The species has remained little changed from the bird that roamed the tundra during the Pleistocene. Nesting takes place in the spring when clutches of four to ten eggs are laid in a scrape on the ground. The chicks are precocial and soon leave the nest. While they are young, both parents play a part in caring for them. The chicks eat insects and young plant growth while the adults are completely herbivorous, eating leaves, flowers, buds, seeds and berries during the summer and largely subsisting on the buds and twigs of willow and other dwarf shrubs and trees during the winter.

Description

The willow ptarmigan is a medium to large ground-dwelling bird and is the most numerous of the three species of ptarmigan. Males and females are about the same size, the adult length varying between 35 and 44 centimetres (14 and 17 in) with a wingspan ranging from 60 and 65 centimetres (24 and 26 in). The weight is 430 to 810 grams (15 to 29 oz). It is deep-chested and has a fairly long neck, a broad bill, short feathered legs and a moderately short rounded tail. In the summer, the male's plumage is marbled brown, with a reddish hue to the neck and breast, a black tail and white wings and underparts. It has a red semicircular comb above each eye, which become red and prominent in the breeding season. The female is similar in appearance but with much smaller eye combs and has brown feathers scattered among the white feathers on her belly. During winter, the body plumage and two central tail feathers of both sexes becomes completely white, except for the black outer rectrices. Their wing feathers remain white all year round. Immature birds resemble the adults. [3] [4]

Female in summer plumage, Alaska Lagopus lagopus Alaska 2.jpg
Female in summer plumage, Alaska

The willow ptarmigan can be distinguished from the closely related rock ptarmigan (Lagopus muta) by its larger size and thicker bill and by the fact that it is not generally found above the tree line while the rock ptarmigan prefers more elevated, barren habitat. The summer plumage is browner and in the winter, the male willow ptarmigan lacks the rock ptarmigan's black stripe between the eyes and bill. [3] The white-tailed ptarmigan (Lagopus leucura) in North America is smaller, has a white tail and finely-barred greyer plumage and lives permanently above the tree line. [5] The distinctive British Isles subspecies L. l. scoticus (red grouse) was once considered a separate true British species but is now classified as a sub-species. This moorland bird is reddish brown all over, except for its white feet. [6]

The voice is low-pitched and guttural and includes chuckles, repeated clucking sounds, and expostulations. When displaying, the male makes rattles and barking noises. [3]

Taxonomy and systematics

Lagopus lagopus foot.jpg
Red grouse, L. l. scoticus, plumage shows less white than other subspecies Red Grouse.jpg
Red grouse, L. l. scoticus, plumage shows less white than other subspecies
Male L. l. alascensis in winter plumage Ptarmigan9.jpg
Male L. l. alascensis in winter plumage
Female L. l. lagopus in summer plumage Lagopus in Abisko.jpg
Female L. l. lagopus in summer plumage

The willow ptarmigan's scientific name, Lagopus lagopus is derived from Ancient Greek lagos (λαγως) 'hare' + pous (πους) 'foot', in reference to the bird's feathered feet which allow it to negotiate frozen ground. [7]

Subspecies

The willow ptarmigan has 16 recognized subspecies. [8] Most differ little in appearance, though the red grouse (L. l. scoticus) is rather distinct. The taxonomy is confused, partly because of the complicated changes in plumage several times a year and the differing color and pattern of the summer plumage: [9]

The willow ptarmigan often hybridises with the black grouse (Tetrao tetrix) and the hazel grouse (Tetrastes bonasia) and occasionally with the western capercaillie (Tetrao urogallus), the spruce grouse (Falcipennis canadensis) and the rock ptarmigan (Lagopus muta). [9]

During the Pleistocene, the willow ptarmigan widely occurred in continental Europe. Authors who recognize paleosubspecies have named the Pleistocene willow ptarmiganL. l. noaillensis (though the older name medius might be the correct one). These marginally different birds are said to have gradually changed from the earlier (Pliocene) Lagopus atavus into the present-day species L. lagopus. Pleistocene willow ptarmigan are recorded from diverse sites until the end of the Vistulian glaciation about 10,000 years ago, when the species, by then all but identical with the living birds, retreated northwards with its tundra habitat. [10] [11] [12] [13] [14] Additionally, mitochondrial DNA of the willow ptarmigan has been recovered from permafrost in the Yukon Territory. [15]

Distribution and habitat

The willow ptarmigan has a circum-boreal distribution. It is native to Canada and the United States, China, Mongolia, the Russian Federation, Kazakhstan, the Czech Republic, Finland, Norway, Sweden, Estonia, Latvia, Lithuania, Germany, the United Kingdom and Ireland. [1] It primarily occupies subalpine and subarctic habitats such as sparse pine and birch forests, thickets with willow and alder trees, heather moors, tundra and mountain slopes. In the winter, females and sub-adults may move to lower altitudes and seek shelter in valleys or in more densely vegetated areas, but adult males usually remain in the subalpine region. [16] The red grouse is common on heather-clad moorland across the north and west of Great Britain and in localised areas of Ireland. [6]

Diet

Alaska willow with twigs, leaves, buds and catkins Salix alaxensis - summer.jpg
Alaska willow with twigs, leaves, buds and catkins

The willow ptarmigan has a varied and seasonal diet. [17] The bird is herbivorous for most of its life and subsists on various plant materials. [18] As juveniles, they may feed on insects due to an inability to digest plant material caused by underdeveloped cecums. In the summer, their diet is highly varied and may consist of berries, flowers, leaves, twigs and seeds. [18]

In Alaska, the main dietary item of the adults at all times of year is willows such as the Alaska willow Salix alaxensis , with leaves being eaten in summer and buds, twigs and catkins supplying the birds' main nutritional needs in winter and early spring. [19] In the early twenty-first century, there has been an increase in shrub expansion in arctic Alaska that is thought to be greatly affecting the willow ptarmigan's winter diet. Because of the way they browse, Ptarmigan help shape the landscape of the area. [19] After heavy snowfalls, the birds cannot access the shorter shrubs as they are blanketed with snow, so they will eat the taller species that poke through. In one study it was found that 90% of the buds of the Alaska willow within their reach had been browsed. [19] This will stunt the willows and create a feedback cycle extending through the entire ecosystem. However, in winters with below average snowfall, the browsing of Ptarmigans will not have such a drastic effect as their feeding will be spread out across 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. [19]

Behavior

Egg, Collection Museum Wiesbaden Lagopus lagopus MWNH 2031.JPG
Egg, Collection Museum Wiesbaden

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 six to ten eggs in a shallow depression on the ground. The nest site is usually in a hidden location at the edge of a clearing. [4]

A small minority of male willow ptarmigan are polygynous but most are monogamous. They are assiduous at guarding both nest and mate, particularly early in the incubation period and when the eggs are nearly ready to hatch. During this time, the greatest danger may be from conspecifics. [20] Although adult willow ptarmigans are herbivores, the newly hatched young also feed on insects. [4] In most other species of grouse, only the female takes care of the young, but the male willow ptarmigan also helps with feeding the brood and protecting them. He may take over completely if the female dies. In particular, the male defends the young from predators and both he and his mate can dive-bomb intruders or lure attackers away by pretending to have a broken wing. Nevertheless, the chicks face many dangers which range from attacks by foxes or birds of prey, getting separated from the rest of the brood, bad weather and coccidiosis. Fewer than 35% of chicks survive to eleven months and only a minority of these reach maturity. Despite this, in favourable seasons, many juveniles may survive and the population of willow ptarmigan is prone to wide fluctuations in size. [4] By September, families begin to form flocks. The females and young migrate to lower altitudes and may overwinter 100 miles (160 km) from their breeding grounds in wooded valleys and hilly country. The males also congregate in small groups but do not usually travel as far as the females. [4]

Cold adaptations

The willow ptarmigan has several behavioral and physiological adaptations that help it survive the long Arctic winter, such as large pectoral muscles that aid in the process of shivering. Researchers have found that these pectoral muscles grow quickly during the first few days of the ptarmigan's life, meaning that the ptarmigan chicks go from having no thermoregulatory ability at hatch to being able to maintain their normal body temperature for hours at 10 °C when they are two weeks old.[ citation needed ] The rapid increase in pectoralis size is caused by increases in muscle fiber diameters (hypertrophy), and cold exposure is not necessary for this muscle development to occur. [21] Ptarmigan also have thick plumage with feather barbules that contain air-filled cavities, [22] contributing to a low heat loss, which aids in thermoregulation while the bird is roosting in burrows in the snow. Ptarmigan can withstand the severe cold because the ambient temperature in the sheltered microclimate of their snow burrows typically exceeds their lower critical temperature. [22]

Status

Widespread and not uncommon in its remote habitat, the willow ptarmigan is classified as a species of "Least Concern" by the IUCN. This is because, even if, as is suspected, numbers are declining slightly, it has a very wide range with a total population estimated at forty million individuals. [1]

Title bird

Winter plumage, Kenai National Wildlife Refuge, Alaska Willow ptarmigan winter plumage.png
Winter plumage, Kenai National Wildlife Refuge, Alaska

The willow ptarmigan was adopted as the state bird of Alaska in 1955. [23] It is also the regional bird of Southern Lapland. [24]

See also

Related Research Articles

<span class="mw-page-title-main">Grouse</span> Tribe of birds

Grouse are a group of birds from the order Galliformes, in the family Phasianidae. Grouse are presently assigned to the tribe Tetraonini, a classification supported by mitochondrial DNA sequence studies, and applied by the American Ornithologists' Union, ITIS, International Ornithological Congress, and others.

<span class="mw-page-title-main">Tundra swan</span> Species of bird

The tundra swan is a small swan of the Holarctic. The two taxa within it are usually regarded as conspecific, but are also sometimes split into two species: Bewick's swan of the Palaearctic and the whistling swan proper of the Nearctic. Birds from eastern Russia are sometimes separated as the subspecies C. c. jankowskii, but this is not widely accepted as distinct, with most authors including them in C. c. bewickii. Tundra swans are sometimes separated in the subgenus Olor together with the other Arctic swan species.

<span class="mw-page-title-main">Black grouse</span> Species of bird

The black grouse, also known as northern black grouse, Eurasian black grouse, blackgame or blackcock, is a large game bird in the grouse family. It is a sedentary species, spanning across the Palearctic in moorland and steppe habitat when breeding, often near wooded areas. They will spend the winter perched in dense forests, feeding almost exclusively on the needles of conifers. The black grouse is one of two species of grouse in the genus Lyrurus, the other being the lesser-known Caucasian grouse.

<span class="mw-page-title-main">Snow bunting</span> Species of bird

The snow bunting is a passerine bird in the family Calcariidae. It is an Arctic specialist, with a circumpolar Arctic breeding range throughout the northern hemisphere. There are small isolated populations on a few high mountain tops south of the Arctic region, including the Cairngorms in central Scotland and the Saint Elias Mountains on the southern Alaska-Yukon border, as well as the Cape Breton Highlands. The snow bunting is the most northerly recorded passerine in the world.

<span class="mw-page-title-main">Snowy owl</span> Species of owl

The snowy owl, also known as the polar owl, the white owl and the Arctic owl, is a large, white owl of the true owl family. Snowy owls are native to the Arctic regions of both North America and the Palearctic, breeding mostly on the tundra. It has a number of unique adaptations to its habitat and lifestyle, which are quite distinct from other extant owls. One of the largest species of owl, it is the only owl with mainly white plumage. Males tend to be a purer white overall while females tend to have more extensive flecks of dark brown. Juvenile male snowy owls have dark markings that may appear similar to females until maturity, at which point they typically turn whiter. The composition of brown markings about the wing, although not foolproof, is the most reliable technique to age and sex individual snowy owls.

<span class="mw-page-title-main">Grey plover</span> Species of bird

The grey plover or black-bellied plover is a large plover breeding in Arctic regions. It is a long-distance migrant, with a nearly worldwide coastal distribution when not breeding.

<span class="mw-page-title-main">Pacific golden plover</span> Species of bird

The Pacific golden plover is a migratory shorebird that breeds during summer in Alaska and Siberia. During nonbreeding season, this medium-sized plover migrates widely across the Pacific.

<span class="mw-page-title-main">Bar-tailed godwit</span> Species of bird

The bar-tailed godwit is a large and strongly migratory wader in the family Scolopacidae, which feeds on bristle-worms and shellfish on coastal mudflats and estuaries. It has distinctive red breeding plumage, long legs, and a long upturned bill. Bar-tailed godwits breed on Arctic coasts and tundra from Scandinavia to Alaska, and overwinter on coasts in temperate and tropical regions of Australia and New Zealand. The migration of the subspecies Limosa lapponica baueri across the Pacific Ocean from Alaska to New Zealand is the longest known non-stop flight of any bird, and also the longest journey without pausing to feed by any animal. The round-trip migration for this subspecies is over 29,000 km (18,020 mi).

<span class="mw-page-title-main">Red grouse</span> Subspecies of bird

The red grouse is a medium-sized bird of the grouse family which is found in heather moorland in Great Britain and Ireland. It is usually classified as a subspecies of the willow ptarmigan but is sometimes considered to be a separate species, Lagopus scoticus. It is also known as the moorcock, moorfowl or moorbird. Lagopus is derived from Ancient Greek lagos (λαγος), meaning "hare", + pous (πους), "foot", in reference to the feathered feet and toes typical of this cold-adapted genus, and scoticus is "of Scotland".

<span class="mw-page-title-main">Rock ptarmigan</span> Species of bird

The rock ptarmigan is a medium-sized game bird in the grouse family. It is known simply as the ptarmigan in Europe. It is the official bird for the Canadian territory of Nunavut, where it is known as the aqiggiq (ᐊᕿᒡᒋᖅ), and the official game bird for the province of Newfoundland and Labrador. In Japan, it is known as the raichō (雷鳥), which means "thunder bird". It is the official bird of Gifu, Nagano, and Toyama Prefectures and is a protected species nationwide. Unlike many arctic bird species, ptarmigan do not gain substantial mass to hibernate over winter.

<span class="mw-page-title-main">Rough-legged buzzard</span> Species of bird

The rough-legged buzzard (Europe) or rough-legged hawk is a medium-large bird of prey. It is found in Arctic and Subarctic regions of North America, Europe, and Russia during the breeding season and migrates south for the winter. It was traditionally also known as the rough-legged falcon in such works as John James Audubon's The Birds of America.

<span class="mw-page-title-main">Spruce grouse</span> Species of bird

The spruce grouse, also known as Canada grouse, spruce hen or fool hen, is a medium-sized grouse closely associated with the coniferous boreal forests or taiga of North America. It is the only member of the genus Canachites.

<span class="mw-page-title-main">Ruff (bird)</span> Species of bird

The ruff is a medium-sized wading bird that breeds in marshes and wet meadows across northern Eurasia. This highly gregarious sandpiper is migratory and sometimes forms huge flocks in its winter grounds, which include southern and western Europe, Africa, southern Asia and Australia.

<span class="mw-page-title-main">Parasitic jaeger</span> Species of bird

The parasitic jaeger or Arctic skua (Europe), is a seabird in the skua family Stercorariidae. It is a migratory species that breeds in Northern Scandinavia, Scotland, Iceland, Greenland, Northern Canada, Alaska, and Siberia and winters across the southern hemisphere. Kleptoparasitism is a major source of food for this species during migration and winter, and is where the name is derived from.

<span class="mw-page-title-main">Aleutian tern</span> Species of bird

The Aleutian tern is a migratory bird living in the subarctic region of the globe most of the year. It is frequently associated with the Arctic tern, which it closely resembles. While both species have a black cap, the Aleutian tern may be distinguished by its white forehead. During breeding season, the Arctic terns have bright red bills, feet, and legs while those of the Aleutian terns are black.

<span class="mw-page-title-main">White-tailed ptarmigan</span> Species of bird

The white-tailed ptarmigan, also known as the snow quail, is the smallest bird in the grouse family. It is a permanent resident of high altitudes on or above the tree line and is native to Alaska and the mountainous parts of Canada and the western United States. Its plumage is cryptic and varies at different times of the year. In the summer it is speckled in gray, brown and white whereas in winter it is wholly white. At all times of year the wings, belly and tail are white. The white-tailed ptarmigan has a diet of buds, leaves, flowers and seeds. The nest is a simple depression in the ground in which up to eight eggs are laid. After hatching, the chicks soon leave the nest. At first they eat insects but later move on to an adult diet, their mother using vocalisations to help them find suitable plant food. The population seems to be stable and the IUCN lists this species as being of "Least Concern".

<i>Lagopus</i> Genus of birds

Lagopus is a small genus of birds in the grouse subfamily commonly known as ptarmigans. The genus contains three living species with numerous described subspecies, all living in tundra or cold upland areas.

<span class="mw-page-title-main">Gyrfalcon</span> Species of bird

The gyrfalcon, the largest of the falcon species, is a bird of prey. The abbreviation gyr is also used. It breeds on Arctic coasts and tundra, and the islands of northern North America and the Eurosiberian region. It is mainly a resident there also, but some gyrfalcons disperse more widely after the breeding season, or in winter. Individual vagrancy can take birds for long distances. Its plumage varies with location, with birds being coloured from all-white to dark brown. These colour variations are called morphs. Like other falcons, it shows sexual dimorphism, with the female much larger than the male. For centuries, the gyrfalcon has been valued as a hunting bird. Typical prey includes the ptarmigan and waterfowl, which it may take in flight; it also takes fish and mammals.

<span class="mw-page-title-main">Snow camouflage</span> Camouflage coloration for winter snow

Snow camouflage is the use of a coloration or pattern for effective camouflage in winter, often combined with a different summer camouflage. Summer patterns are typically disruptively patterned combinations of shades of browns and greys, up to black, while winter patterns are dominated by white to match snowy landscapes.

References

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