Siberian crane

TheSiberian crane(Leucogeranus leucogeranus), also known as theSiberian white craneor thesnow crane, is abirdof the family Gruidae, thecranes. They are distinctive among the cranes: adults are nearly allsnowy white, except for their blackprimaryfeathers that are visible in flight, and with twobreeding populationsin the Arctictundraof western andeastern Russia. The eastern populationsmigrateduring winter to China, while the western population winters inIranand (formerly) inBharatpur, India.
Among the cranes, they make the longest distancemigrations. Their populations, particularly those in the western range, have declined drastically in the 20th century due tohuntingalong their migration routes andhabitat degradation. The world population was estimated in 2010 at about 3,200 birds, mostly belonging to the eastern population with about 93% of them wintering in thePoyang Lakebasin in China, a habitat that may be altered by theThree Gorges Dam.
The Siberian crane wasformally describedbyPeter Simon Pallasin 1773 and given thebinomial nameGrus leucogeranus.Thespecific epithetis derived from the classical Greek wordsleukosfor "white" andgeranosfor a "crane".Ustad Mansur, a 17th-century court artist and singer ofJahangir, had illustrated a Siberian crane about 100 years earlier.The genusMegalorniswas used for the cranes byGeorge Robert Grayand this species was included in it, whileRichard Bowdler Sharpesuggested a separation fromGrusand used the genusSarcogeranus.The Siberian crane lacks the complextrachealcoils found in most other cranes but shares this feature with thewattled crane. The unison call differed from that of most cranes and some authors suggested that the Siberian crane belonged in the genusBugeranusalong with the wattled crane. Comparisons of the DNA sequences of cytochrome-b however suggest that the Siberian crane is basal among theGruinaeand the wattled crane is retained as the sole species in the genusBugeranusand placed as a sister to theAnthropoidescranes.
Amolecular phylogeneticstudy published in 2010 found that the genusGrus, as then defined, waspolyphyletic.In the resulting rearrangement to createmonophyleticgenera, the Siberian crane was moved to the resurrected genusLeucogeranus.The genusLeucogeranushad been introduced by the French biologistCharles Lucien Bonapartein 1855.
Adults of both sexes have a pure white plumage except for the blackprimaries,alulaand primarycoverts. Thefore-crown, face and side of head is bare and brick red, thebillis dark and the legs are pinkish. Theirisis yellowish. Juveniles are feathered on the face and the plumage is dingy brown. There are no elongated tertial feathers as in some other crane species.During breeding season, both the male and female cranes are often seen with mud streaking their feathers; they may intentionally smear mud on their feathers, which has been hypothesized to aidcamouflageon thenest. The call is very different from thetrumpetingof most cranes and is agoose-like high pitched whistlingtoyoya. This is a fairly large species of crane, typically weighing 4.9–8.6 kg (11–19 lb) and standing about 140 cm (4 ft 7 in) tall. The wingspan is reportedly from 210 to 260 cm (6 ft 11 in to 8 ft 6 in) and length is 115–127 cm (45–50 in). Males are on average larger than females.The average weight of adults in one study was 6.81 kg (15.0 lb) while juvenile birds were slightly heavier on average at 7.1 kg (16 lb).There is a single record of an outsized male of this species weighing 15 kg (33 lb). Usually, this crane is usually slightly smaller in weight and height than some other cranes, particularly thesarus crane,wattled craneandred-crowned crane.
Thebreeding areaof the Siberian crane formerly extended between theUralsandOb riversouth to theIshimandTobolrivers and east to theKolymaregion. The populations declined with changes inlanduse, the draining of wetlands foragricultural expansionand hunting on their migration routes. The breeding areas in modern times are restricted to two widely disjunct regions. The western area in theriver basinsof the Ob,KondaandSossvaand to the east a much larger population inYakutiabetween theYanaand theAlazeyarivers.Like most cranes, the Siberian crane inhabits shallowmarshlandsand wetlands and will often forage in deeper water than other cranes. They show very highsite fidelityfor both their wintering and breeding areas, making use of the same sites year after year.The western population winters in Iran and some individuals formerly wintered in India south toNagpurand east toBihar. The eastern populations winter mainly in thePoyang Lakearea in China.
Siberian cranes are widely dispersed in their breeding areas and are highlyterritorial. They maintain feeding territories in winter but may form small and looseflocks, and gather closer at their winterroosts. They are verydiurnal, feeding almost all throughout the day. When feeding onsubmerged vegetation, they often immerse their heads entirely underwater. Whencalling, the birds stretch their neck forward.The contexts of several calls have been identified and several of thesevary with sex.Individual variationis very slight and most calls have a dominant frequency of about 1.4kHz.The unison calls, duets betweenpairedmales and female however are more distinctive with marked differences across pairs.The female produces a higher pitched call which is the "loo" in the duetted "doodle-loo" call. Pairs will walk around other pairs to threaten them and drive them away from their territory.In captivity, one individual was recorded to have lived for nearly 62 yearswhile another lived for 83 years.
These cranes areomnivorouswith a tendency to plant matter. In the summer grounds they feed on a range of plants including the roots of hellebore (Veratrummisae), seeds ofEmpetrum nigrumas well as small rodents likelemmingsandvoles,earthworms, andfish. They were earlier thought to be predominantly fish eating on the basis of theserratededge of their bill, but later studies suggest that they take animal prey mainly when the vegetation is covered by snow. They alsoswallow pebbles and gritto aid in crushing food in theircrop.In their wintering grounds in China, they have been noted to feed to a large extent on the submerged leaves ofVallisneria spiralis.Specimens wintering in India have been found to have mainly aquatic plants in their stomachs. They are however noted to pick upbeetlesand bird's eggs in captivity.
Siberian cranes return to the Arctic tundra around the end ofApriland beginning ofMay.The nest is usually on the edge of lake inboggyground and is usually surrounded by water. Most eggs are laid in the first week ofJunewhen the tundra is snow free. The usualclutchis two eggs, which areincubatedby the female after the second egg is laid, with the male standing guard nearby. The eggs hatch in about 27 to 29 days. The young birdsfledgein about 80 days. Usually only a single chick survives due to aggression between young birds. The population increase per year is less than 10%, the lowest recruitment rate among cranes. Their success in breeding may further be hampered by disturbance fromreindeerand sometimes dogs that accompanyreindeer herders.Captive breeding was achieved by the International Crane Foundation atBarabooafter numerous failed attempts. Males often killed their mates and captive breeding was achieved byartificial inseminationand the hatching of eggs by other crane species such as thesandhilland usingfloodlightsto simulate the longer daylengths of theArctic summer.
This species breeds in twodisjunctregions in the arctic tundra ofRussia; the western population along theOb,Yakutia, and westernSiberia. It is a long distancemigrantand among the cranes, makes one of the longest migrations.The eastern population winters on theYangtze RiverandLake Poyangin China, and the western population inFereydoon Kenarin Iran.  The central population, which once wintered inKeoladeo National Park, Bharatpur, isextinct.
Theconservation statusof the Siberian crane is very serious. In 2008, the decreasing world population was estimated to be around 3500–4000 individuals, nearly all of them belonging to the eastern breeding population.Of the 15 crane species, this is the only regarded ascritically endangered, the highest threatened category by theIUCN(thewhooping craneof North America has a smaller but rising population that is better protected, giving the species a status of endangered.) The western population of the Siberian crane had dwindled to four in 2002 and subsequently it was thought to be extirpated, but a single individual, named "Omid", has wintered in Iran since 2006–2007.The wintering site at Poyang in China holds an estimated 98% of the population and is threatened byhydrologicalchanges caused by theThree Gorges Damand other water development projects.
Historical recordsfrom India suggest a wider winter distribution in the past including records fromGujarat, nearNew Delhiand even as far east asBihar.In the19th century, larger numbers of birds were noted to visit India.They were sought after by hunters andspecimen collectors. In 1974, as many as 75 birds wintered in Bharatpur, but this population declined to a single pair in 1992 and the last bird was seen in 2002.An individual that escaped from a private menagerie was shot in theOuter Hebridesin 1891.The western population may even have wintered as far west as Egypt along the Nile.
Satellitetelemetrywas used to track the migration of a flock that wintered in Iran. They were noted to rest on the eastern end of theVolga Delta.Satellite telemetry was also used to track the migration of the eastern population in the mid-1990s, leading to the discovery of new resting areas along the species' flyway in eastern Russia and China.The Siberian crane is one of the species to which theAgreement on the Conservation of African-Eurasian Migratory Waterbirds(AEWA) applies and is subject ofthe Memorandum of Understanding concerning Conservation Measures for the Siberian Craneconcluded under theBonn Convention.
For theYakutsandYukaghirs, the white crane is a sacred bird associated withsun, spring and kind celestial spiritsajyy. In yakutepicsOlonkhoshamans and shamanessestransform into white cranes.