Red grouse
| Red grouse | ||||||||||||
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Red Grouse ( Lagopus lagopus ) |
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| Lagopus lagopus | ||||||||||||
| ( Linnaeus , 1758) |
The willow ptarmigan ( Lagopus lagopus ) is a bird art , in the family of pheasant-like (Phasianidae) to the grouse heard (Tetraoninae). The species is found in northern Europe, northern Asia and northern North America. The European breeding area is estimated to be more than 3 million square kilometers. Several subspecies are distinguished.
The IUCN classifies the red grouse as not endangered ( least concern ) because the distribution area is very large and so far only a moderate decline in the population has been observed. The world population is estimated to be around 40 million sexually mature individuals.
Appearance
With a body length of 35 to 40 centimeters, the red grouse is slightly larger than its close relative, the ptarmigan ( Lagopus muta ). The wingspan is between 55 and 65 centimeters. The weight varies between 500 and 700 grams. Although it prefers to stay on the ground, the red grouse is relatively short-legged and has comparatively long wings.
The cock and hen wear a red-brown summer dress, which is set off by dark transverse waves. The underside as well as the legs are white. The winter plumage is completely white, except for the black outer tail feathers. The bright red "roses" above the eyes are striking. Males can be distinguished from females because in spring they have a closed reddish-brown color of the head and upper breast, which contrasts sharply with the white of the rest of the plumage.
In the wild, the willow grouse can be confused with the rock ptarmigan if they are sympatric . During courtship, however, the male of the Ptarmigan can be recognized by the white body plumage and the small number of dark head feathers. In winter they are distinguished by the black stripe on the head. The rest of the time, both males and females are almost indistinguishable in the open field.
Locomotion
Red grouse prefer to stay on the ground and move at a rapid pace. The flight is typical of grouse with an alternation of rapid wing beats and a glide on outstretched and downwardly bent wings.
Distribution area
The distribution area of the red grouse extends from Scandinavia to deep into Siberia and further to North America . The largest part of the distribution area takes the northeast Asia. The northern limit of distribution mostly coincides with the coastline of the Northern Arctic Ocean. From the Arctic Islands, Kolgujew , Novaya Zemlya , the New Siberian Islands and a number of the Arctic Islands of Canada such as King William Island are settled. In the Atlantic area, the red grouse inhabits both Newfoundland and the British Isles. On the latter, the Scottish red grouse ( Lagopus lagopus scotica ) is represented as a subspecies .
The red grouse was also a breeding and resident bird in Central Europe until the 17th century and was found in northwestern Poland. Recent breeding occurrences are all due to release actions. Until now, however, successful exposure attempts have only been made in the High Fens in the border area between Belgium and Germany. After amelioration measures and reforestation, however, the population declined again and was probably extinguished at the end of the 1960s.
The distribution areas of the Ptarmigan and Willow Grouse partially overlap. The two species coexist in winter but do not form mixed shoals. During the breeding season, the two species compete for suitable breeding grounds.
hikes
Red grouse are resident birds in the greater part of their distribution area , which stay in the area of their breeding grounds even in the winter months. Only the northernmost populations migrate a little further south in the winter half-year. The annual time of departure from the tundra depends on the formation of a closed snow cover there and its increasing depth. So in a less snowy and warm autumn, the move takes place slowly. Red grouse often stay longer at suitable feeding places. They use few ecological routes to the south. As a rule, the train runs along rivers, the banks of which offer rich shrub vegetation. The Pechora , Seida , Vorkuta , Ob , Yenisei , Lena and Kolyma rivers are known for the fact that on a few days during the migration large groups of 100 to 300 red grouse can be observed continuously in their vicinity, at an altitude of 50 to 200 Meters past. The spring migration back to the breeding areas is also slow. On the Taimyr Peninsula it lasts up to 2½ months and coincides with the mass migration of the reindeer . Numerous troops of red grouse accompany the herds of reindeer moving to the northwest and roam among the feeding reindeer.
habitat
The willow grouse occurs in a wide range of biotopes, ranging from barren arctic tundras to swampy thickets and pine forests. The most important biotopes are tundra, raised bogs in the forest zone, forest steppes and forest and shrub thickets of the subalpine belt in the mountains. Since willows and birches are the main food in the winter months, they must always be available. In some areas of Scandinavia, individual populations of the red grouse can also be found on heather areas. In these populations, the heather also plays an important role in the diet. Forest is only a main biotope in northern Scandinavia, on the Kola peninsula and in Karelia . These biotopes are only used intensively during the breeding season. In the rest of the time, willow grouse live as line birds, which can be found in various areas with berry bushes in autumn and in open areas with rich shrub vegetation in winter.
wintering
In most of their range, red grouse live under winter conditions that are characterized by constant low temperatures, storms and a short, bright time of day and deep snow. During this time they spend most of the day in small flocks of five to 15 birds in snow chambers. At sunrise they leave these snow chambers and immediately go in search of food. To do this, they usually fly a short distance. Usually the whole group moves from bush to bush, where they eat the buds and end shoots from the lower branches. Typical for places where red grouse used to eat in the winter half-year are 30 to 50 meter wide strips in the snow that consist of overlapping tracks.
Food intake in winter is only intensive in the first hours of twilight, during the middle of the day the birds rest for two to three hours either in the snow chambers or, if the weather conditions are favorable, in surface depressions. This is followed by another phase of intensive food intake at dusk.
The snow chambers of a swarm are usually very close to one another. Usually the distance between two sleeping chambers is only one to 1.5 meters. The chambers are between 14 and 21 inches high, 17 to 18 inches wide and 25 inches long. The tunnel that leads to the snow chamber is 0.5 meters long on average. In exceptional cases, however, it can reach a length of up to two meters.
food
The winter food of the red grouse consists almost exclusively of the terminal shoots and buds of willow and birch and, to a lesser extent, of alder. As the winter progresses, the birds are forced to eat thicker shoots due to the exhaustion of resources. Their nutritional value is lower and the energy required for biting and digesting is higher. Snow-free areas are used by them to pick up leaves and overwintered berries of lingonberries and crowberries , as well as horsetail stalks and leaves of rosemary heather and similar plant components.
In summer, the diet of adult red grouse consists of green parts of plants, berries, seeds as well as mosses and mushrooms. Insects are also eaten during this time. In the chicks, on the other hand, insects, spiders and small mollusks predominate in the first days of life. However, chicks also start eating plant foods very early.
Reproduction
Red grouse usually enter into a monogamous relationship that can last for several breeding periods. The link between the couple is the district. If a partner bird is lost, another male or female takes on as a partner. When the population density is high and the biotope conditions are favorable, the individual breeding grounds are almost adjacent to one another. The territory is selected by the rooster who occupies and defends it. The size of the area depends on the micro-relief of the respective area, on the vegetation, the location of the waters and, to a large extent, on the respective population density. In the tundra, the area size varies between 0.23 and 7 hectares and is 0.86 hectares when the population is high. The mating season lasts for over two months and begins with the first appearance of the feathers of the spring dress. This can still be the case on the move to the breeding grounds. The courtship ritual of the male includes courtship flight with courtship song and courtship with stretched neck, fanned tail and hanging wings in the immediate vicinity of the female.
The nest is built as close as possible to cover. To build a nest, a shallow hollow is dug into the ground. The hen uses plant parts from the area for upholstery. At the beginning of May 6 to 11 eggs are laid, from which the chicks hatch after about 25 days. The female breeds alone. It usually only leaves the nest three to six times in 24 hours to eat for five to 48 minutes at a time. The rooster stays in the area during the breeding season and often keeps watch near the nest. He always accompanies the female while searching for food. He attacks other males or predators that appear near the nest on the ground or in the air.
The Dunenjungen usually hatch in the morning, the shells can be picked the night before. They are those who flee the nest and who roam around on the first day, moving further and further away from the nest. With the hatching of the chicks, the territoriality of the males disappears completely. Both parent birds feed and lead the chicks, but the female alone tucks them during the first days of life. The young birds can fly at 30 to 35 days, but can fly from an age of 12 days. They are sexually mature at one year.
Natural causes of death
The red grouse prey on a number of very different predators. Chicks are also eaten by skuas, as well as arctic and herring gulls. For the gyrfalcon and the arctic fox , the ptarmigan is an essential prey animal, but only the arctic fox has an influence on the grouse population, especially in years after a lemming gradation . The gyrfalcon, on the other hand, is too rare to have any effect on the population.
Adverse weather conditions during the hatching phase of the chicks have a major impact on the population. Cold and late spring years also mean that most females do not brood after snowy winters. A high population density, which regionally leads to a lack of winter food, can also mean that the majority of red grouse do not reproduce.
Red grouse and human
The red grouse is a game in parts of its range. Hunting is common in the period from September to October, when the birds gather in flocks and the nutritional status of the birds is still good. Up until the first half of the 20th century, red grouse was also caught with nets.
Others
In the 2000s, the computer game series Moorhuhnjagd , in which users shot down virtual grouse on the computer , enjoyed great popularity.
supporting documents
literature
- Hans-Günther Bauer, Einhard Bezzel and Wolfgang Fiedler (eds.): The compendium of birds in Central Europe: Everything about biology, endangerment and protection. Volume 1: Nonpasseriformes - non-sparrow birds. Aula-Verlag Wiebelsheim, Wiesbaden 2005, ISBN 3-89104-647-2 .
- Otto E. Höhn: The ptarmigan. 3. Edition. Westarp Sciences, Hohenwarsleben 2004, ISBN 3-89432-245-4 .
- RL Potapov, VE Flint (ed.): Handbook of the birds of the Soviet Union. Volume 4: Galliformes, Gruiformes. Aula Verlag, Wiesbaden 1989, ISBN 3-89104-417-8 .
- Richard Sale: A Complete Guide to Arctic Wildlife. Christopher Helm Publisher, London 2006, ISBN 0-7136-7039-8 .
Single receipts
- ↑ BirdLife Factsheet on the Red Grouse , accessed September 27, 2016.
- ↑ Birdlife website on the red grouse, accessed on May 30, 2013 (PDF; 266 kB).
- ↑ BirdLife Factsheet on the Red Grouse , accessed May 30, 2013.
- ↑ Sale, p. 160.
- ↑ Potapov & Flint, 1989. p. 151.
- ↑ Bauer et al., P. 167.
- ↑ a b c Sale, p. 161.
- ^ Potapov & Flint, 1989, p. 156.
- ↑ a b Potapov & Flint, 1989, p. 157.
- ↑ a b Potapov & Flint, 1989, p. 158.
- ^ Potapov & Flint, 1989, p. 163 and p. 164.
- ^ Potapov & Flint, 1989, p. 164.
- ^ Potapov & Flint, 1989, p. 165.
- ^ Potapov & Flint, 1989, p. 166.
- ^ Potapov & Flint, 1989, p. 160.
- ^ Potapov & Flint, 1989, p. 161.
- ↑ a b c Potapov & Flint, 1989, p. 163.
- ^ Potapov & Flint, 1989, p. 166 and p. 167.
- ^ Potapov & Flint, 1989, p. 167.
Web links
- Lagopus lagopus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings of Lagopus lagopus in the Internet Bird Collection
- Red grouse feathers