The willow ptarmigan ( ); ''Lagopus lagopus'') or willow grouse is a bird in the

grouse Grouse are a group of birds from the order (biology), order Galliformes, in the family (biology), family Phasianidae. Grouse are presently assigned to the Tribe (biology), tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetr ...

subfamily Tetraoninae of the pheasant family

Phasianidae Phasianidae is a family (biology), family of heavy, ground-living birds, which includes pheasants, grouse, partridges, junglefowl, chickens, Turkey bird, turkeys, Old World quail, and peafowl. The family includes many of the most popular Game (hu ...

. It is also known colloquially as awebo bird. The willow ptarmigan breeds in

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 3 ...

and other forests and

moorland Moorland or moor is a type of Habitat (ecology), habitat found in upland (geology), upland areas in temperate grasslands, savannas, and shrublands and the biomes of montane grasslands and shrublands, characterised by low-growing vegetation on So ...

s in northern Europe, the

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, in particular in the provinces of

Newfoundland and Labrador Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the populatio ...

and

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

. It is the state bird of Alaska. In the summer the birds are largely brown, with dappled plumage, while in the winter they are white with some black feathers in their tails. The species has remained little changed from the bird that roamed the

during the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

. 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 Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

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.

Taxonomy

The willow ptarmigan was

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

in 1758 by the Swedish naturalist

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

in the

tenth edition Tenth may refer to: Numbers * 10th, the ordinal form of the number ten * One tenth, , or 0.1, a fraction, one part of a unit divided equally into ten parts. ** the SI prefix deci- ** tithe, a one-tenth part of something * 1/10 of any unit of me ...

of his ''

Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...

'' under the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...

''Tetrao lagopus''. He specified the type locality as "Europae alpinis" but this has been restricted to Sweden. The willow ptarmigan is now one of four species placed in the genus ''

Lagopus ''Lagopus'' is a genus of birds in the grouse subfamily commonly known as ptarmigans (). The genus contains four living species with numerous described subspecies, all living in tundra or cold upland areas. Taxonomy and etymology The genus ''L ...

'' that was introduced in 1760 by the French zoologist

Mathurin Jacques Brisson Mathurin Jacques Brisson (; 30 April 1723 – 23 June 1806) was a French zoologist and natural philosophy, natural philosopher. Brisson was born on 30 April 1723 at Fontenay-le-Comte in the Vendée department of western France. Note that page 14 ...

. The word ''lagopus'' is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for a ptarmigan. The word original came from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

λαγωπους/''lagōpous'' meaning "hare-footed", from λαγως/''lagōs'' meaning "hare" and πους/''pous'', ποδος/''podos'' meaning "foot". 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: Fifteen

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

are recognised: * ''L. l. variegata'' Salomonsen, 1936 – islets off west Norway * ''L. l. lagopus'' (

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

, 1758) – Scandinavia and north Russia * ''L. l. rossica'' Serebrovski, 1926 – Baltic States to central Russia * ''L. l. koreni''

Thayer Thayer may refer to: Places ;United States * Thayer, Illinois * Thayer, Indiana * Thayer, Iowa * Thayer, Kansas * Thayer, Michigan * Thayer, Missouri * Thayer, Nebraska *Thayer, West Virginia * Thayer County, Nebraska * Thayer Street, Providence, ...

Bangs Bang, bang!, or bangs may refer to: Products * M1922 Bang rifle, a US semi-automatic rifle designed by Søren Hansen Bang * Bang, a List of model car brands, model car brand * Bang (beverage), an energy drink Geography * Bang, Central African ...

, 1914 – Siberia to

Kamchatka Peninsula The Kamchatka Peninsula (, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific ...

* ''L. l. maior'' Lorenz, T, 1904 – north

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

and southwest Siberia * ''L. l. brevirostris'' Hesse, 1912 – east

to central south Siberia and west Mongolia * ''L. l. kozlowae''

Portenko Leonid Oleksandrovych Portenko (; 11 October 1896 – 26 May 1972) was a Soviet ornithologist of Ukrainian origin who carried out extensive zoogeographic studies on the birds of the northern and north-eastern Palearctic realm. He was born in Smil ...

, 1931 – north Mongolia and south Siberia * ''L. l. sserebrowsky''

Domaniewski Janusz Witold Domaniewski (30 April 1891 – 15 March 1954) was a Polish ornithologist and conservationist. He was a curator at the Warsaw zoological museum and was involved in the establishment of a nature preserve in the Tatra Mountains, Tat ...

, 1933 – northeast Mongolia to southeast Siberia and northeast China * ''L. l. okadai'' Momiyama, 1928 –

Sakhalin Sakhalin ( rus, Сахали́н, p=səxɐˈlʲin) is an island in Northeast Asia. Its north coast lies off the southeastern coast of Khabarovsk Krai in Russia, while its southern tip lies north of the Japanese island of Hokkaido. An islan ...

(Russia) * ''L. l. alascensis'' Swarth, 1926 – Alaska (USA) * ''L. l. alexandrae'' Grinnell, 1909 –

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

Kodiak Island Kodiak Island (, ) is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the Un ...

, south, southeast Alaskan islands (USA) and northwest British Columbia (Canada) * ''L. l. leucoptera'' Taverner, 1932 – northernmost Canada and its Arctic islands * ''L. l. alba'' ( Gmelin, JF, 1789) – north Canada * ''L. l. ungavus''

Riley Riley may refer to: Businesses * Riley (brand), British sporting goods brand founded in 1878 * Riley Motor, British motorcar and bicycle manufacturera 1890–1969 * Riley Technologies, American auto racing constructor and team, founded by Bob ...

, 1911 – northeast Canada * ''L. l. alleni'' Stejneger, 1884 – Newfoundland (Canada) The willow ptarmigan often hybridises with the

black grouse The black grouse (''Lyrurus tetrix''), also known as northern black grouse, Eurasian black grouse, blackgame or blackcock, is a large Aves, bird in the grouse family. It is a Bird migration, sedentary species, spanning across the Palearctic in m ...

(''Tetrao tetrix'') and the

hazel grouse The hazel grouse (''Tetrastes bonasia''), sometimes called the hazel hen, is one of the smaller members of the grouse family of birds. It is a sedentary species, breeding across the Palearctic as far east as Hokkaido, and as far west as eastern a ...

(''Tetrastes bonasia'') and occasionally with the western capercaillie (''Tetrao urogallus''), the spruce grouse (''Falcipennis canadensis'') and the

rock ptarmigan The rock ptarmigan (''Lagopus muta'') 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'' (ᐊᕿ� ...

(''Lagopus muta''). During the

, the willow ptarmigan widely occurred in

continental Europe Continental Europe or mainland Europe is the contiguous mainland of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mean the whole of Europe – and, by som ...

. Authors who recognize

paleosubspecies A chronospecies is a species derived from a sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a population that is p ...

have named the Pleistocene willow ptarmigan ''L. 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 The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Vistulian glaciation about 10,000 years ago, when the species, by then all but identical with the living birds, retreated northwards with its

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

. Additionally, mitochondrial DNA of the willow ptarmigan has been recovered from

permafrost Permafrost () is soil or underwater sediment which continuously remains below for two years or more; the oldest permafrost has been continuously frozen for around 700,000 years. Whilst the shallowest permafrost has a vertical extent of below ...

in the

Yukon Territory Yukon () is a territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s westernmost territory and the smallest ...

Description

The willow ptarmigan is a medium to large ground-dwelling bird and is the most numerous of the three species of

ptarmigan ''Lagopus'' is a genus of birds in the grouse subfamily commonly known as ptarmigans (). The genus contains four living species with numerous described subspecies, all living in tundra or cold upland areas. Taxonomy and etymology The genus ''L ...

. Males and females are about the same size, the adult length varying between with a wingspan ranging from . The weight is . 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 Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...

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 A comb is a tool consisting of a shaft that holds a row of teeth for pulling through the hair to clean, untangle, or style it. Combs have been used since prehistoric times, having been discovered in very refined forms from settlements dating ba ...

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 Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the Bird wing, wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those ...

. Their wing feathers remain white all year round. Immature birds resemble the adults. Lagopus lagopus Alaska 2

The willow ptarmigan can be distinguished from the closely related

(''Lagopus muta'') by its larger size and thicker bill and by the fact that it is not generally found above the

tree line The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually low ...

while the rock ptarmigan prefers more elevated, barren

. 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. The

white-tailed ptarmigan The white-tailed ptarmigan (''Lagopus leucura''), also known as the snow quail, is the smallest Aves, bird in the grouse tribe. It is a permanent resident of high altitudes on or above the tree line and is native to Alaska and the mountainous ...

(''Lagopus leucura'') in North America is smaller, has a white tail and finely-barred greyer plumage and lives permanently above the tree line. The distinctive

red grouse The red grouse (''Lagopus scotica'') is a medium-sized bird of the grouse family which is found in Calluna, heather moorland in Great Britain and Ireland. It was formerly classified as a subspecies of the willow ptarmigan (''Lagopus lagopus'') ...

of the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

was once considered to be a subspecies. This

bird is reddish brown all over, except for its white feet. The voice is low-pitched and guttural and includes chuckles, repeated clucking sounds, and expostulations. When displaying, the male makes rattles and barking noises. Lagopus lagopus foot

Distribution and habitat

The willow ptarmigan has a circum-boreal distribution. It is native to

and the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

Mongolia Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south and southeast. It covers an area of , with a population of 3.5 million, making it the world's List of countries and dependencies by po ...

, the

Russian Federation Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, the

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

Estonia Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Ru ...

Latvia Latvia, officially the Republic of Latvia, is a country in the Baltic region of Northern Europe. It is one of the three Baltic states, along with Estonia to the north and Lithuania to the south. It borders Russia to the east and Belarus to t ...

Lithuania Lithuania, officially the Republic of Lithuania, is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea, bordered by Latvia to the north, Belarus to the east and south, P ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

and

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

. It primarily occupies

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

and

subarctic The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of hemiboreal regions and covering much of Alaska, Canada, Iceland, the north of Fennoscandia, Northwestern Russia, Siberia, and the Cair ...

habitats such as sparse

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...

and

forests, thickets with

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

and

alder Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species ex ...

trees, heather moors,

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. The red grouse is common on heather-clad moorland across the north and west of Great Britain and in localised areas of Ireland. Willow Ptarmigan Lagopus lagopus distribution in Europe map.png, Distribution in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Willow Ptarmigan Lagopus lagopus distribution in North America map.png, Distribution in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Diet

The willow ptarmigan has a varied and seasonal diet. The bird is

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

for most of its life and subsists on various plant materials. 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. In Alaska, the main dietary item of the adults at all times of year is

s such as the Alaska willow '' Salix alaxensis'', with leaves being eaten in summer and buds, twigs and

catkin A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind- pollinated ( anemophilous) but sometimes insect-pollinated (as in '' Salix''). It contains many, usually unisexual flowers, arra ...

s supplying the birds' main nutritional needs in winter and early spring. 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. 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. 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.

Behavior

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. A small minority of male willow ptarmigan are

polygynous Polygyny () is a form of polygamy entailing the marriage of a man to several women. The term polygyny is from Neoclassical Greek πολυγυνία (); . Incidence Polygyny is more widespread in Africa than in any other continent. Some scholar ...

but most are

monogamous Monogamy ( ) is a relationship of two individuals in which they form a mutual and exclusive intimate partnership. Having only one partner at any one time, whether for life or serial monogamy, contrasts with various forms of non-monogamy (e.g. ...

. 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 Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

. Although adult willow ptarmigans are

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

s, the newly hatched young also feed on

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s. In most other

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, 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 Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

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

fox Foxes are small-to-medium-sized omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull; upright, triangular ears; a pointed, slightly upturned snout; and a long, bushy tail ("brush"). Twelve species ...

es or

birds of prey Birds of prey or predatory birds, also known as (although not the same as) raptors, are hypercarnivorous bird species that actively predation, hunt and feed on other vertebrates (mainly mammals, reptiles and smaller birds). In addition to speed ...

, to getting separated from the rest of the brood, bad weather, and

coccidiosis Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody ...

. 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. By September, families begin to form flocks. The females and young migrate to lower altitudes and may overwinter 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.

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. 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. Ptarmigan also have thick plumage with feather barbules that contain air-filled cavities, 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. Willow ptarmigan winter plumage

Status

Widespread and not uncommon in its remote habitat, the willow ptarmigan is classified as a species of "

Least Concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

" by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. 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.

Title bird

The willow ptarmigan was adopted as the state bird of Alaska in 1955. It is also the regional bird of

Southern Lapland Southern Lapland or Rear Bothnia ( or ''Peräpohja''; or ''Överbotten''; ) was the northernmost part of the historical province of Ostrobothnia, and it has sometimes been considered a separate region, but it is now part of the Lapland region. ...

References

External links

Game & Wildlife Conservation Trust Red Grouse PageRSPB Red Grouse PageVideo clip of male Willow Ptarmigan in winter
* (for

Belarus Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an a ...

) with worldwide RangeMap
Willow Ptarmigan videos
on the Internet Bird Collection

VIREO {{Taxonbar, from=Q178702

willow ptarmigan The willow ptarmigan ( ); ''Lagopus lagopus'') or willow grouse is a bird in the grouse subfamily Tetraoninae of the pheasant family Phasianidae. It is also known colloquially as awebo bird. The willow ptarmigan breeds in birch and other forests ...

Grouse Holarctic birds

Symbols of Alaska

Taxonomy

Description

Distribution and habitat

Diet

Behavior

Cold adaptations

Status

Title bird

See also

References

External links