Grouse are a group of birds from the order Galliformes. They are often considered a family Tetraonidae, though the American Ornithologists' Union and many others include grouse as a subfamily Tetraoninae in the family Phasianidae. Grouse inhabit temperate and subarctic regions of the northern hemisphere, from pine forests to moorland and mountainside,from 83° North (Ptarmigan in northern Greenland) to 28° North (Attwater's Prairie Chicken in Texas). Presumably they evolved in this zone.
Grouse are heavily built like other Galliformes such as chickens. They range in length from 31 cm (12 in) to 95 cm (37 in), in weight from 0.3 kg (11 oz) to 6.5 kg (14 lb). Males are bigger than females—twice as heavy in the Capercaillie, the biggest member of the family. Grouse have feathered nostrils. Their legs are feathered to the toes, and in winter the toes too have feathers or small scales on the sides, an adaptation for walking on snow and burrowing into it for shelter. Unlike other Galliformes, they have no spurs
These birds feed mainly on vegetation—buds, catkins, leaves, and twigs—which typically accounts for over 95 percent of adults' food by weight. Thus their diet varies greatly with the seasons. Hatchlings eat mostly insects and other invertebrates, gradually reducing their proportion of animal food to adult levels. Several of the forest-living species are notable for eating large quantities of conifer needles, which most other vertebrates refuse. To digest vegetable food, grouse have big crops and gizzards, eat grit to break up food, and have long intestines with well-developed caeca in which symbiotic bacteria digest cellulose.
Forest species flock only in autumn and winter, though individuals tolerate each other when they meet. Prairie species are more social, and tundra species (ptarmigans, Lagopus) are the most social, forming flocks of up to 100 in winter. All grouse spend most of their time on the ground, though when alarmed, they may take off in a flurry and go into a long glide.
Most species stay within their breeding range all year, but make short seasonal movements; many individuals of the Ptarmigan (called Rock Ptarmigan in America) and Willow Grouse (called Willow Ptarmigan in America) migrate hundreds of kilometers
In all but one species (the Willow Grouse), males are polygamous. Many species have elaborate courtship displays on the ground at dawn and dusk, which in some are given in leks. The displays feature males' bright-colored combs and in some species, bright-colored inflatable sacs on the sides of their necks. The males display their plumage, give vocalizations that vary widely between species, and may engage in other activities such as drumming or fluttering their wings, rattling their tails, and making display flights. Occasionally males fight.
The nest is a shallow depressions on the ground, often in cover, with a scanty lining of plant material. The female lays one clutch, but may replace it if the eggs are lost. She begins to lay about a week after mating and lays one egg every day or two; the clutch comprises 5 to 12 eggs. The eggs have the shape of hen's eggs and are pale yellow, sparsely spotted with brown. On laying the second-last or last egg, the female starts 21 to 28 days of incubation. Chicks hatch in dense yellow-brown down and leave the nest immediately. They soon develop feathers and can fly a little before they are two weeks old. The female (and the male in the Willow Grouse) stays with them and protects them till their first autumn, by which time they reach their mature weight (except in the male capercailies). They are sexually mature the following spring but often do not mate until later years.
Grouse make up a considerable part of the vertebrate biomass in the Arctic and Subarctic. Their numbers may fall sharply in years of bad weather or high predator populations—significant grouse populations are a major food source for lynx, foxes, martens, and birds of prey. However, because of their large clutches, they can recover quickly.
The three tundra species have maintained their former numbers. The prairie and forest species have declined greatly because of habitat loss, though popular game birds such as the Red Grouse and the Ruffed Grouse have benefited from habitat management. Most grouse species are listed by the IUCN as "least concern" or "near threatened", but the Greater and Lesser Prairie-Chicken are listed as "vulnerable" and the Gunnison Sage-Grouse is listed as "endangered". Some subspecies, such at Atwater's Prairie-Chicken and the Cantabrian Capercailie, and some national and regional populations are also in danger
Grouse are game, and hunters kill millions each year for food, sport, and other uses. The male Black Grouse's tail feather are a traditional ornament for hats in areas such as Scotland and the Alps. Folk dances from the Alps to the North American prairies imitate the displays of leking males
The Sooty Grouse, fuliginosus, is a species of forest-dwelling grouse native to North America's Pacific Coast Ranges. It is so closely related to the Dusky Grouse, Dendragapus, that until recently there was some debate whether they were separate species.
Adults have a long square tail, light gray at the end. Adult males are mainly dark with a yellow throat air sac surrounded by white, and a yellow wattle over the eye during display. Adult females are mottled brown with dark brown and white marks on the underparts.
Their breeding habitat is the edges of conifer and mixed forests in mountainous regions of western North America, from southeastern Alaska and Yukon south to California. Their range is closely associated with that of various conifers. The nest is a scrape on the ground concealed under a shrub or log.
They are permanent residents but move short distances by foot and short flights to denser forest areas in winter, with the odd habit of moving to higher altitudes in winter.
These birds forage on the ground, or in trees in winter. In winter, they mainly eat fir and douglas-fir needles, occasionally also hemlock and pine needles; in summer, other green plants (Pteridium, Salix), berries (Gaultheria, Mahonia, Rubus, Vaccinium), and insects (particularly ants, beetles, grasshoppers) are more important. Chicks are almost entirely dependent on insect food for their first ten days.
Males sing with deep hoots on their territory and make short flapping flights to attract females. Females leave the male's territory after mating.
Sooty Grouse are experiencing some population decline from habitat loss at the southern end of its range in southern California
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 Grouse but is sometimes considered to be a separate species Lagopus scoticus. It is also known as the moorfowl or moorbird.
The Red Grouse is differentiated from the Willow Grouse and Ptarmigan by its plumage being reddish brown and not having a white winter plumage. The tail is black and the legs are white. There are white stripes on the underwing and red combs over the eye. Females are less reddish than the males and have less conspicuous combs. Young birds are duller and lack the red combs.
Birds in Ireland are sometimes thought to belong to a separate subspecies L. l. hibernica. They are slightly paler than those in Britain and the females have yellower plumage with more finely barred underparts. This may be an adaptation to camouflage them in moorland with higher grass and sedge content and less heather.
It is identified by its chut!chut!chut! call, or the 'Goback, goback vocalisation. The wings make a whirring sound when the bird is disturbed from a resting place.
Grouse populations display periodic cycling, where the population builds up to very high densities only to crash a few years later, and then recover. The main driver of this cyclic pattern is thought to be the parasitic nematode worm Trichostrongylus tenuis.
However, in his book, V. C. Wynne-Edwards suggests that the primary reason for mortality in grouse population is Homeostasis depending largely on food availability and that the 'Grouse disease', due to the parasitic worm Trichostrongylus tenuis is a mistaken diagnosis of the after effects of social exclusion.
The Red Grouse is endemic to the British Isles; it has developed in isolation from other subspecies of the Willow Grouse which are widespread in northern parts of Eurasia and North America.
It is found across most parts of Scotland, including Orkney, Shetland and most of the Outer Hebrides. They are only absent from urban areas, such as the central belt, the flatter areas of the north-east and around Fife.
In Wales there are strong populations in places but their range has retracted. They are now largely absent from the far south, their main strongholds being Snowdonia, the Brecon Beacons and the Cambrian Mountains. There are reports of Welsh birds crossing the Bristol Channel to Exmoor.
In England it is mainly found in the north - places such as the Lake District, the Langdales , Northumberland, County Durham, much of Yorkshire, the Pennines and the Peak District, as far south as the Staffordshire Moorlands. There is an isolated introduced population on Dartmoor, and overspill Welsh birds visit the Shropshire Hills such as Long Miynd, where they breed. The Exmoor population would now appear to be extinct, with the last birds sighted as recently as 2005. An introduced population in Suffolk died out by the early 20th century, though a population on Cannock Chase in Staffordshire lasted longer.
In Ireland it is found locally in most parts of the country.
Its typical habitat is upland heather moors away from trees. It can also be found in some low-lying bogs and birds may visit farmland during hard weather.
The British population is estimated at about 250,000 pairs with around 1-5,000 pairs in Ireland. Numbers have declined in recent years and birds are now absent in areas where they were once common. Reasons for the decline include loss of heather due to overgrazing, creation of new conifer plantations and a decline in the number of upland gamekeepers. Some predators such as the Hen Harrier feed on grouse and there is ongoing controversy as to what effect these have on grouse numbers.
Red Grouse have been introduced to the Fagnes region of Belgium but the population there collapsed in the early 1970s.
The Red Grouse is considered a game bird and is shot in large numbers during the shooting season which traditionally starts on the 12th of August, known as the Glorious Twelfth.
Shooting can take the form of 'walked up' (where shooters walk across the moor to flush grouse and take a shot) or 'driven' (where grouse are driven, often in large numbers. by 'beaters' towards the guns who are hiding behind a line of 'butts'). Many moors are intensively managed to increase the density of grouse. Areas of heather are subjected to controlled burning; this allows fresh young shoots to regenerate, which are favoured by the grouse. Extensive predator control is a feature of grouse moor management: the foxes,the stoats and the crows are usually heavily controlled on grouse moors.
Often, protected species such as the raptors can also fall foul of illegal control. However, this is a controversial topic and the extent to which it occurs on grouse moors is hotly contested between conservation groups and shooting interests. It is nevertheless a topic that generates a lot of media attention in relation to grouse moors and shooting.
In recent decades the practice of using of medicated grit and direct dosing of birds against an endoparasite, the strongyle worm or Threadworm (Thrichostrongylus tenuis), has become part of the management regime on many moors
Due to their economic and social importance and some interesting aspects of their biology, red grouse have been widely studied. They were the subject of some of the earliest studies of population biology in birds, as detailed in The Grouse in Health and in Disease by Lovat in 1911. Since the mid-20th century they have been subject to ongoing study by many organisations and individuals. Much work has been conducted by the Institute of Terrestrial Ecology in the eastern Cairngorms, and by the Game & Wildlife Conservation Trust in the Central Highlands. There are a wide range of research activities still going on today and a wealth of published literature exists on all aspects of grouse biology.
The Red Grouse is widely known as the logo of The Famous Grouse whisky and an animated bird is a character in a series of its adverts, familiar to all in Duty Free shops. The Red Grouse is also the emblem of the journal British Birds.
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