Collar chicken

Collar chicken
Collar grouse ( Bonasa umbellus )
Systematics
Class : Birds (aves) Order : Chicken birds (Galliformes) Family : Pheasants (Phasianidae) Subfamily : Grouse (Tetraoninae) Genre : Bonasa Type : Collar chicken
Scientific name of the  genus
Bonasa
Stephens , 1819
Scientific name of the  species
Bonasa umbellus
( Linnaeus , 1766)

The collar grouse ( Bonasa umbellus , Syn .: Bonasus umbellus ) is a medium-sized grouse that is native to North America. It is a distinct resident bird and fourteen subspecies are currently recognized.

The collar grouse is an important game bird in North America. Towards the end of the 1990s, when the cyclical rise in the collar grouse peaked, more than one million collar grouse were shot annually in the US states of Michigan, Minnesota and Wisconsin alone.

Appearance

The collar chicken comes in a gray and red color morph . The head, neck and back of the gray morph are gray-brown. The chest is lightened and streaked. The underside of the body and the flanks are largely white. Overall, gray collar hens are drawn very differently. The throat is clearly lightened in many individuals. The tail is the same gray-brown as the back. At the end of the tail there is a broad black band that ends with a gray band. The tail can be fanned out so that it almost forms a semicircle.

The red-brown morph has a similar color distribution, but the plumage is browner overall. This morph appears more uniform in its color dress. There are a number of mixed types between the two morphs. As a rule, both morphine always occur in the respective local populations, but the ratio changes over the years. Several studies have meanwhile come to the conclusion that the proportion of a morph in the respective population is essentially influenced by the weather of the previous winter. Snowy winters favor the gray morphs. It has also been found that gray morphs reach a higher average age than red morphs.

The eponymous feather collar on the neck can be found in both sexes. In the male, however, these elongated neck feathers are somewhat more pronounced. The feathers are also extended and can be set up. The legs are feathered down to the feet.

Body measurements and weight

Males of the collar grouse reach a wing length of 171 to 196 millimeters, the tail length is between 129 and 174 millimeters and the beak is between 24 and 31 millimeters long. Females tend to be a bit smaller. They reach a wing length of 165 to 190 millimeters, the tail is between 120 and 159 millimeters and the beak is between 23.5 and 29.3 millimeters long.

As with other grouse, weight fluctuates over the year. Collared chickens reach their maximum weight around November, when males weigh an average of 660 grams and females 585 grams. The males reach the minimum weight in spring shortly before the start of the courtship phase and again towards the end of August, when they have passed through the moult. They then weigh an average of 620 grams. The minimum weight of the females falls in March and June. At the end of the winter season in March they weigh an average of 520 grams and in June, after the breeding phase, 495 grams. The highest weight that has so far been determined in a collar chicken is 840 grams.

distribution and habitat

Temperate rainforest, Wells Gray Provincial Park

The collar grouse occurs from the Appalachian Mountains in the east of the USA via Canada to Alaska . In the United States, it is found throughout the northern midwest . Here the distribution area extends from East Minnesota to Maine . In the south, the collar grouse occurs as far as Virginia and Georgia . In the western United States, the distribution area extends from western Montana to the west coast. They colonize habitats with very different climates. They occur in Alaska in regions with an average temperature of −25 ° C in January and 12 ° C in June, but also colonize regions in Arkansas with an average temperature of 5 ° C in January and 25 ° C in June. The forest forms in which they find suitable living conditions are correspondingly different. They occur in the temperate rainforest of North America, where conifers dominate, but also colonize semi-arid deciduous forests. In principle, collar hens prefer mixed forests, in which aspen, poplar, birch, willow, apples , oak and hemlock are found. The presence of the American quivering aspen is of particular importance . This can be observed particularly clearly in the regions that belong to the northern limit of distribution. Here collar grouse occur only in the narrow forest bands along rivers, where this tree species is also represented. Catkins , buds and twig ends of this tree species represent an essential winter food. In the more southern distribution area collar grouse are more likely to be found in mixed forests with their dense undergrowth than in pure deciduous forests.

Collared chickens are extremely faithful to their location, which has also contributed to the formation of the numerous subspecies. The maximum distance between the recovery site and the original Bering site is only 19.3 kilometers so far.

food

The most important winter food of the collar hens are the catkins, buds and twig ends of various deciduous trees and plants of the undergrowth. In addition to ash trees, various types of birch are of particular importance, along with willows, apples, cherries, hops beeches and blueberries . The food composition, however, is strongly dependent on the respective regional forest forms. In the US state of Minnesota, for example, the large-toothed poplar plays a particularly important role during the winter months, alongside the American quaking aspen . In the US state of Utah, on the other hand, the Virginian bird cherry is the most important food crop in winter; ash and maple trees also play a special role. In the Canadian prairie province of Alberta, where winters are particularly severe, winter food consists of 80 percent of the buds of ash trees and willow trees.

In spring, the range of food crops used increases, but the plant species still dominate, which also played a particularly important role during the winter half-year. In the summer, different berries such as strawberries, raspberries, blueberries and the like are eaten. From August onwards, the plants that are most important in winter food gradually begin to dominate again. Animal food does not play a major role in the diet of adult birds and only in exceptional cases exceeds more than 10% of the food eaten. It is different with the young birds. During the first two weeks of life, the frilled chicks eat at least 70% animal food. During the third and fourth week of life, the proportion of animal food gradually falls to 30%. In September the young birds usually eat insects to the same extent as the ennobled birds. Ants are mainly eaten, along with beetles, grasshoppers and caterpillars. When the frilled young birds gradually switch to vegetable food, they first eat grasses, then various types of berries, and finally the buds and catkins of various shrubs and trees.

behavior

Abandoned snow chamber of a ruffed grouse. In the snow you can clearly see the imprints of the wings left by the ruffled grouse.

The frilled chicken's nest with an unusually large clutch

Like most hazel grouse, the collar grouse spend most of the time on the ground. If they are surprised, they fly up with a loud roar of wings. In the snowy northern range, collar grouse stay in snow chambers for most of the day, which they only leave to look for food in the morning and evening hours. In Alberta, Canada, ruffians spent an average of 16.4 minutes on the snowpack just after sunrise in the morning before digging a new snow chamber. They left their chambers a second time after sunset and then searched for food for an average of 24.4 minutes.

The courtship of the collar hens is very noticeable. The males court the females with loud flapping of their wings. The tail feathers are spread wide. The loud, muffled instrumental sound is generated by the movement of air through the wings. The collar hens often sit on tree trunks lying on the ground. Each “call” consists of 38 to 51 wing beats, each lasting 10 to 12 seconds. During the first two to three seconds the males flap their wings three to four times, then they increase very quickly to up to 20 wing beats per second before slowing down again. The instrumental sound can still be heard from a distance of 400 to 500 meters, under very good control even up to a distance of one kilometer.

Egg, Museum Wiesbaden collection

The females nest on the ground. Typical nesting locations are the root plates of trees or locations under trunks lying on the ground or the privacy protection of bushes are used. The full clutch has an average of 11.5 eggs. If a second clutch is laid after the first clutch has been lost, this comprises an average of 7.5 eggs. The females lay 36 hours apart; they start incubating after the last egg has been laid. It only breeds the female, who usually only leaves the nest twice a day during the breeding season to eat. It stays away from the nest for an average of 20 to 40 minutes. The chicks are able to fly at an age of ten to twelve days.

Duration

The population density has decreased across the entire North American continent in recent years. The main cause is a loss of suitable habitats. The species is still widespread in Canada. It is not considered endangered. Many states in the United States allow this species to be hunted from September through January. However, hunting is not considered to be a major factor in the decline in the population. Collared chickens are generally considered to be a species whose population size fluctuates greatly.

The collar grouse has been successfully reintroduced in some areas. An increase in the number of collar hens raised in human care has already been carried out successfully. The species can at least theoretically withstand strong hunting pressure, as it reproduces very strongly. To do this, however, sufficient forest land must be available so that the species can recover. In North America, it has been suggested that greater attention should be paid to the population cycles of the collar grouse when hunting. These run over ten to twelve years. In good years, the stock is often five times as good as in bad years and can increase up to ten times. The reasons for these population cycles are not yet fully understood.

Systematics

Assigned to the genus Bonasa

The collar grouse is occasionally placed in the genus Bonasa together with the hazel grouse and the black-breasted hazel grouse . Despite a superficial similarity, the two hazel grouse differ conspicuously in their behavior. Hazel grouse form a monogamous pair bond. They lack the conspicuous courtship plumage or the conspicuous courtship actions for which the collar grouse is known. For this reason, the collar grouse is more often assigned to the genus Bonasa alone and the two hazel grouse are placed in the separate genus Tetrastes .

Subspecies

The collar grouse is a distinct resident bird, so that several subspecies have developed that are specially adapted to their respective local conditions. The gray and red morphs described under appearance occur in all subspecies:

• B. u. yukonensis Grinnell , 1916
• B. u. umbelloides ( Douglas , 1829)
• B. u. labradorensis Ouellet, 1991
• B. u. castanea Aldrich & Friedmann , 1943
• B. u. affinis Aldrich & Friedmann, 1943
• B. u. obscura Todd , 1947
• B. u. sabini (Douglas, 1829)
• B. u. brunnescens Conover , 1935
• B. u. togata (Linnaeus, 1766)
• B. u. mediana Todd, 1940
• B. u. phaios Aldrich & Friedmann, 1943
• B. u. incana Aldrich & Friedmann, 1943
• B. u. monticola Todd, 1940
• B. u. umbellus (Linnaeus, 1766)

supporting documents

literature

• Henninger, WF (1906): A preliminary list of the birds of Seneca County, Ohio. Wilson Bull. 18 (2): 47-60. PDF
• Don L. Johnson (1995): Grouse & Woodcock: A Gunner's Guide . Krause Publications, ISBN 0-87341-346-6
• Steve Madge , Phil McGowan, and Guy M. Kirwan : Pheasants, Partridges and Grouse. A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails and Sandgrouse of the world. Christopher Helm, London 2002, ISBN 0-7136-3966-0 .
• Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 .

Web links

Commons : Bonasa umbellus  - album with pictures, videos and audio files

• Bonasa umbellus inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved September 30, 2013.

Individual evidence

1. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 70.
2. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 60 and SS 61.
3. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 61. The data from 307 males and 151 females were included in the analysis.
4. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 61.
5. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 65.
6. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 65.
7. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 66.
8. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 66 and p. 67.
9. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 67.
10. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 67.
11. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 68.
12. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 69.
13. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 70.
14. ↑ Steve Madge, Phil McGowan and Guy M. Kirwan: Pheasants, Partridges and Grouse - A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails and Sandgrouse of the world , Christopher Helm, London 2002, ISBN 0-7136- 3966-0 , p. 374