Sickle chicken
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Sickle Grouse ( Falcipennis falcipennis ) |
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| Falcipennis falcipennis | ||||||||||||
| ( Hartlaub , 1855) |
The Siberian grouse ( Falcipennis Falcipennis , due to the unclear systematic position often Dendragapus Falcipennis ) is an East Asian representative of the grouse (Tetraoninae) within the family of pheasant-like (Phasianidae). The chicken bird, the size of a hazel grouse, occurs mainly in the taiga of the lower Amur region and on Sakhalin . It is named after the tapering hand wings, which give the small wings a sickle-shaped shape. It is believed that stocks of the species have declined over the past 40 years; therefore the sickle grouse is currently listed in the early warning stage for endangered species.
Appearance
The basic color of the roosters is a dark gray-black. The head and collar are usually darker, the collar plumage is set off from the rest of the body plumage with a fine light stripe. Light, almost white spots are arranged irregularly over the entire trunk; on the belly side they show a typical heart shape. The breast shield is black. The under tail-coverts have white tips and are banded indistinctly in light gray. The tail feathers are black and have a clear white shaft line. The tips of the control springs are white. The short beak is slate gray; A white streak runs from the base of the beak to behind the eye. The dark legs are feathered down to the base of the toes. The red, bald areas of the skin over the eyes, the so-called "roses", are very strongly developed, especially in spring; they recede somewhat as the year progresses.
Hens are a little smaller and, apart from the time before the start of laying, a little lighter than the roosters. On a reddish-brown or slate-gray background, they are usually densely spotted with white and scaled in various shades of brown, reddish brown and gray. The white spots are larger and more pronounced in the females than in the males, but it disappears with increasing age, especially in the shoulder area.
When young, sickle fowl are speckled reddish brown, yellowish hues can also dominate. The throat is whitish, the tail brown. The sides of the body are lightly striated across. Young hens are clearly spotted white on the shoulder. The neck feathers of young roosters are shorter than those of perennial ones.
The sex dimorphism is very clearly pronounced in the sickle grouse in terms of plumage; However, the sexes differ only slightly in weight and size. Roosters and hens weigh a maximum of 740 grams, but reach this maximum weight at different times: the hens are heaviest before laying begins, the roosters in autumn.
If the observation conditions are good, the sickle hen should not be confused. When flying up, however, the hazel hens , which are common in the distribution area, are difficult to distinguish from sickle hens; The hazel grouse's significantly longer escape distance can serve as a good identification aid.
Move
Sickle chickens rarely fly, but they can also cover longer distances in the air. For example, a hen with a transmitter flew 5 kilometers at a time. In the event of danger, sickle hens sit motionless for a long time and rely on their camouflage. When enemies of the ground approach, they fly up a tree; The escape distance is very short, especially when people and dogs approach. During the upward flight, a clear rumble of the wing is usually audible. Due to the small wing area, the wing beat frequency is very high. During courtship, the roosters make short show runs and flutter jumps.
voice
Sickle chickens tend to be silent outside of the courtship season, but contact calls, aggression sounds and warning calls can be heard throughout the year, depending on the situation. The rooster mating call is a vuuuuuuuuuuuuuiiiiiiieeee that carries up to 80 meters and lasts for about three seconds , which increases significantly towards the end. This call begins with a humming tone and then turns into a vibrating sequence of sounds. This singing is interrupted by clicks that sound like kloppp , and for which it is unclear whether they are produced vocal or by flapping wings. In addition, wing buzzing and tail rattling can be heard during courtship. Females who come to the courtship place gently lure; leading females have a range of warning calls; those in front of enemies cause the young to duck and remain motionless, those in front of enemies cause them to fly.
distribution and habitat
The sickle grouse is common in a relatively small area in East Asia. The focus of the occurrence is on the lower reaches of the Amur. From the coast of the Sea of Okhotsk the breeding area runs northwards approximately to the mouth of the Maja in the Aldan ; The sickle grouse is widespread in the Aldan highlands , and there may also be occurrences further north. The western borders are largely unknown; Secure data on the status of the south and east roofs of the Stanowoi Mountains are available. The southern border lies on the middle reaches of the Amur, further east near the coast the distribution area extends to the southern Sichote-Alin . The sickle grouse found on the entire island of Sakhalin with the exception of the southernmost fifth. Occasionally, occurrences north and west of the known distribution area have been reported; It is not known whether these existed or still exist. Whether the sickle grouse still occurs as a breeding bird in the northern Hinggan Mountains in China cannot be said with certainty at the moment.
In the area of distribution, the sickle grouse occurs in coniferous forests of the Okhotsk type, but, contrary to other statements, seems to avoid dense areas of the dark coniferous forest taiga itself. Character trees are the Ayan spruce ( Picea jezoensis ), the East Siberian fir ( Abies nephrolepis ), the Dahurian larch ( Larix gmelinii ) and the Korean pine ( Pinus koraiensis ). It prefers cool and humid forest sections that are severely disturbed by wind or snow breaks , as well as succession forest areas after forest fires or bark beetle disasters. Important for the type are dense undergrowth and mossy or Porst vegetated sections. During the rearing of the young, the sickle hen also inhabits pure larch forest and, in the higher areas, stone pine stands . The habitats vary a lot with the seasons: in winter it prefers gaps between spruce and fir forests in their decay phase, where deep snow enables snow caves to be created. In summer, larch forests on mountain ridges are ideal habitat for sickle grouse. Edge zones to open bog areas or forest areas along streams or rivers seem to be particularly favorable. Besides the conifers, important food crops are dwarf shrubs such as lingonberries , bogberries , cloudberries and crowberries . Foraging for food, sickle chickens can also be found in forest sections that are dominated by birch and aspens . The sickle grouse is distributed from the lowlands to the tree line, which lies in the breeding area between 1400 and 1500 meters. During the summer months, the birds prefer to stay in higher regions and then penetrate into the mountain pine and knee wood regions above the tree line. The summer and winter territories can be identical, border one another, but also be a few kilometers apart.
There are only a few statements about the space requirements of the species; Numbers that suggest a very thin and patchy population in the range could be related to the very secret way of life of the species. Telemetrically obtained data from some core zones of the distribution area indicate about 6 to 8 individuals per square kilometer. The roosters occupy courtship territories which cover an average of 5.5 hectares and of which only the approximately 1 hectare large actual courtship areas are defended; Particularly attractive courtship areas are on hilltops and small hills.
Food and subsistence
Like other grouse, sickle grouse feed mainly on needles, leaves and fruits of some dwarf shrubs, buds and the seed pods of mosses. In spring, insects, especially ants, and other invertebrates play an essential role in the hens' diet. The composition of the food varies greatly according to the season: During the months with snow cover, i.e. from the beginning of October to the end of April, sickle fowl feed almost exclusively on pine needles. During this time, they consume around 150 grams of fresh needles a day. This food supply is available in abundance, so that sickle chickens can get by with an activity time of 4 to 5 hours. During the snow-free months, the diet consists mainly of needles and flowers of the Dahurian larch as well as leaves and berries of dwarf shrubs, especially the lingonberry. Buds of various deciduous trees and their young leaves, sedge flowers and the berries of the Canadian dogwood are also consumed during this time. Spruce and pine needles are also regularly used in summer, but are insignificant for the total amount of energy absorbed. Animal food is eaten on occasion; the proportion of arthropods seems to be greater in young animals than in adult birds. In the first weeks of life, the young birds feed exclusively on insects. Large amounts of gastroliths are swallowed during the frost-free period .
The needle food is mostly obtained from the lower branches of a tree; the branch tips are preferred. The leaves and berries of the dwarf shrubs are plucked at a leisurely pace.
behavior
Outside of the courtship and breeding season, sickle hens live in small, loose groups of 3 to 7 animals. However, they avoid the proximity of conspecifics during the breeding and guiding period. The species spends a lot of time on plumage care; sand bathing in particular is an essential part of plumage hygiene. At temperatures above minus 20 degrees, the birds spend the night on a tree branch, usually close to the trunk. At lower temperatures, they sleep in snow caves about 30 centimeters deep. Together with their American relative, the pine grouse , they have an extremely short distance to escape from people. Occasionally sickle chickens can even be grabbed or caught on a low branch with a noose. However, their camouflage is so good that it is difficult to make out a bird that remains motionless. If a sickle hen does fly up, it usually lands after a few meters and disappears in the dense undergrowth. In open spaces, which sickle hens visit especially in autumn, they are significantly more vigilant and move away from people at a relatively great distance.
Breeding biology
The sickle grouse's reproductive system has not yet been adequately researched. There seem to be females who mate with the same male for several years and also raise the chicks in the male's territory; other females migrate after mating and breed far away from the courtship area. Males evidently mate with several females on occasion, but they are often unsuccessful if no female appears. Three-year-old roosters seem to have the greatest success in mating. The roses with a height of 6 millimeters and the cervical and neck feathers with a length of almost 50 millimeters are also the most striking. Most hens mate with territorial roosters, but there are occasional mating between hens and non-territorial roosters.
Courtship
With the first aperen spots from the end of March, the winter groups dissolve and the roosters move into their courtship territories. Mating roosters are at least two years old, previous years do not mate and are tolerated in the mating territories of the older ones. A little later, around mid-April, the females become intolerant and then migrate to the vicinity of the courtship grounds. The preferred courtship areas are in pole wood islands with little undergrowth; Here the roosters are on the one hand somewhat protected from predators, on the other hand the sparse floor vegetation allows good visibility and an unobstructed course of the courtship ritual. At the beginning of the courtship, the roosters leave their roosts with loud buzzing of their wings. This is followed by impressive flights, again with a loud flapping of wings. These flights rarely go more than 20 meters; often a tree serves as a stopover. The singing verse is performed at a certain, mostly elevated point within the courtship area. At the beginning the rooster assumes the impressive position, rests the neck feathers and fans the control feathers several times, which creates a rattle of about 10 meters. The head plumage, however, is tight, which gives the head area a helmet-like appearance and emphasizes the red bulges above the eyes. Then the rising stanza begins with trembling wings and ends with a click. This is followed by a jump of 180 degrees and a double click. A unit ends with a forward jump. When jumping, the roosters flutter their wings loudly. The main mating season is in May. The courtship is only interrupted by short periods of feeding; in bad weather or very low temperatures the roosters do not courtship. When roosters court each other within earshot of each other, there are regular confrontations, which usually end without contact fights.
Females ready to mate fly with a loud, noticeable flight noise near the courtship area, usually on a tree. If one lands next to the rooster, copulation takes place very quickly, which lasts about 4 to 5 seconds; then the females move away while the male continues to courtship after a short break.
Clutch and brood
About 7 to 12 days after mating, the hens occupy a breeding area that is usually only a few 100 meters away from the mating site, but in exceptional cases it can also be a few kilometers away. The first eggs are laid on the bare ground, only gradually a nest hollow is created, which is covered with twigs and stalks. The nests can be in different places, for example in the dense swamp porous scrub, in shrub birch bogs or in the undergrowth of a spruce-fir forest. Often the nest location is covered at the top by branches or bushes. The egg-laying begins in the second week of May. A full clutch consists of 5 to 7 pointed oval eggs with an average size of 45 × 31 millimeters, which have a light brown basic color and are slightly darkly speckled.
The hen begins to brood firmly before the last egg; the incubation period is around 24 days. During the breeding season, the hen leaves the nest twice a day to look for food. After an early clutch loss, there is a smaller additional clutch. After hatching, the young are fidgeted for a few hours, but then led away from the nest. The young immediately eat food independently; Newly hatched chicks are rowed every 15 minutes, with increasing age the breeding intervals lengthen. Chicks start fluttering at four days and can fly onto the lower branches of a tree as early as a week. The family is in constant acoustic contact; if a youngster loses touch, it utters far-reaching sounds reminiscent of "crying". The hen and chicks spend the first five weeks of life on the ground, later together on the lower branches of a conifer. It was at this age that the first youth feather dress developed. The young live with the hen until the beginning of September, after which the hen leaves the chicks, which remain together for a certain time before they leave the nursery area. The dismigration proceeds differently. Some migrate immediately at distances of up to 15 kilometers, others stay close to their breeding area and only leave it in the following spring. The roosters do not take part in rearing their young.
Systematics
The systematic position of the sickle grouse is unclear. At the moment it forms the second species of the genus Falcipennis next to the fir grouse . This assignment is controversial: Birdlife records it together with the two species of rock mountain fowl ( D. obscurus and D. fuliginosus ) and the pine grouse ( D. canadensis ) in the genus Dendragapus . Morphological and behavioral similarities point to a close relationship with the fir grouse. More recent molecular biological investigations have not yet brought any final clarification of the relationships, but show a relative special position of the sickle grouse within the Falcipennis / Dendragapus group.
No subspecies of the sickle grouse are currently distinguished. Small, only sparsely white-spotted birds occurring on Sakhalin were classified as a separate subspecies F. f. Muratai , however, are now considered to be color variants occurring in the entire distribution area.
Life expectancy and exposure
No information is available on the life expectancy of the species. Hafner et al. Ringed birds which they estimated to be at least 6 to 7 years old. However, a high percentage of birds do not even survive the first year of life. The Siberian grouse has a number of natural enemies: lynx , brown bear , wolf and Zobel , and goshawk , sparrow hawks , buzzards , great gray owl and Ural live in the breeding area. In winter the sable is the main enemy, as most birds of prey and owls leave the area. Brooding hens and young birds that leave the family are particularly at risk. In the long term, the regularly occurring forest fires and storm disasters can have a positive effect, since sickle grouse prefer to colonize the regrowing forest. However, forest fires in rapid succession, which are often triggered by camping mushroom or berry pickers, prevent the forest from growing back and thus fragment the range of the species. The greatest danger for the sickle grouse comes from large-scale felling without subsequent afforestation, as is very common in the range occurrence. After a while, these felling areas become grassy and make the habitat for the sickle grouse uninhabitable. However, there are eight protected areas of considerable size in the breeding area of the sickle grouse, which alone could be sufficient to ensure a viable sickle grouse population in the long term. Although the sickle hen is protected all year round in Russia, it is poached or used as bait for sable traps. Nevertheless, the resulting inventory losses appear to be only minor.
Stock situation
There is no information available on the stock situation relating to the entire distribution area. Inventory analyzes carried out or estimated previously appear to have been too pessimistic. Overall, the species is listed in the early warning level of endangered species due to suspected decline in populations. The species is thought to be extinct in China.
Individual evidence
- ↑ Weblink data sheet Birdlife
- ↑ personal communication from Franz Hafner
- ↑ VSU (1989) p. 118.
- ^ Hafner & Andreev (1998) p. 40.
- ↑ Hafner & Andreev (1998) pp. 87f.
- ↑ Storch (2006) p. 32.
- ↑ VSU (1989) p. 118.
- ↑ Hafner & Andreev (1998) p. 30.
- ↑ Andreev et. al (2001) p. 408.
- ^ Hafner & Andreev (1998) p. 37.
- ^ Hafner & Andreev (1998) p. 80.
- ^ Hafner & Andreev (1998) p. 80.
- ^ Hafner & Andreev (1998) p. 80.
- ↑ VSU (1989) p. 125.
- ^ Hafner & Andreev (1998) p. 68.
- ↑ Andreev et al. (2001) p. 411.
- ↑ Hafner & Andreev (1998) p. 45.
- ^ Hafner & Andreev (1998) p. 37.
- ↑ Hafner & Andreev (1998) pp. 52-68.
- ↑ ITIS data sheet
- ↑ Boag & Schroeder (1992) Systematics
- ↑ Andreev et al. (2001) p. 420.
- ↑ Dimcheff et al. (2002) p. 205.
- ↑ VSU (1989) p. 120.
- ^ Hafner & Andreev (1998) p. 22.
- ^ Hafner & Andreev (1998) p. 98.
- ^ Hafner & Andreev (1998) p. 98.
- ↑ Data sheet Birdlife (2006)
literature
- Alexander V. Andreev, Franz Hafner, Siegfried Klaus and Hartmut Gossow: Displaying behavior and mating system in the Siberian Spruce Grouse (Falcipennis falcipennis Hartlaub 1855). In: Journal of Ornithology 142 (4) (2001), pp. 404-424.
- David. A. Boag and Michael. A. Schroeder. Spruce Grouse (Falcipennis canadensis). In: The Birds of North America Online (A. Poole, Ed.) Ithaca: Cornell Lab of Ornithology 1992.
- Derek E. Dimcheff, Sergei V. Drovetski, and David P. Mindella: Phylogeny of Tetraoninae and other galliform birds using mitochondrial 12S and ND2 genes. In: Molecular Phylogenetics and Evolution 24 (2002), pp. 203-215.
- Franz Hafner, Alexander V. Andreev et al. : The sickle grouse - mysterious jungle bird in eastern Siberia Special publication by the Natural Science Association for Carinthia. Klagenfurt 1998, ISBN 3-85328-014-5 .
- Florian Möllers, Wiltraud Engländer, Siegfried Klaus and Alexander V. Andreev: A grouse in a dense forest - variability in the expressive behavior of the sickle grouse Falcipennis falcipennis. In: Journal of Ornithology 136 (4) (1995), pp. 398-399.
- VD Il'ičev and VE Flint (eds.): Handbook of Birds of the Soviet Union. Vol. 4 Galliformes-Gruiformes. Ziemsen Wittenberg 1989, ISBN 3-7403-0027-2 , pp. 117-126 (= VSU)
- Grouse. Status Survey and Conservation Action Plan 2006-2010. engl., compiled by Ilse Storch (PDF file; 4.48 MB)
Web links
- Good overview + images
- Data sheet Birdlife
- Data sheet ITIS
- Falcipennis falcipennis in the Red List of Threatened Species of the IUCN 2013.2. Listed by: BirdLife International, 2012. Retrieved February 5, 2014.