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词条 Saiga antelope
释义

  1. Taxonomy and phylogeny

  2. Evolution

  3. Characteristics

  4. Ecology and behaviour

  5. Habitat and distribution

  6. Threats and conservation

      Hunting saiga    Physical barriers    Climatic variability    Mass mortalities 1980 to 2015    2015–2016 epizootic  

  7. References

  8. Further reading

  9. External links

{{redirect|Saiga|the shotgun named after the antelope|Saiga-12|the rifle|Saiga semi-automatic rifle}}{{Speciesbox
| name = Saiga antelope
| fossil_range = {{fossil range|Pleistocene|Recent}}
| image = Saiga antelope at the Stepnoi Sanctuary.jpg
| image_caption = Saiga antelope at the Stepnoi Nature Sanctuary
| status = CR
| status_system = IUCN3.1
| status_ref = [1]
| display_parents = 2
| parent_authority = Gray, 1843
| taxon = Saiga tatarica
| authority = (Linnaeus, 1766)
| subdivision_ranks = Subspecies
| subdivision =
  • S. t. tatarica
  • S. t. mongolica

| synonyms_ref = [2]
| synonyms = {{collapsible list|title=List
|Antilope saiga Pallas, 1766
|Antilope scythica Pallas, 1766
|Capra tatarica Linnaeus, 1766
|Capra sayga Forster, 1768
|Cemas colus Oken, 1816
|Ibex imberbis Gmelin, 1760
}}
| range_map = Saiga tatarica historic¤t distribution.jpg
| range_map_caption = Reconstructed range (white) and current distribution of the two subspecies Saiga tatarica tatarica (green) and S. t. mongolica (red).
}}

The saiga antelope ({{IPAc-en|ˈ|s|aɪ|ɡ|ə}}, Saiga tatarica) is a critically endangered antelope that originally inhabited a vast area of the Eurasian steppe zone from the foothills of the Carpathian Mountains and Caucasus into Dzungaria and Mongolia.

They also lived in Beringian North America during the Pleistocene. Today, the dominant subspecies (S. t. tatarica) is only found in one location in Russia (in the Republic of Kalmykia and Astrakhan Oblast) and three areas in Kazakhstan (the Ural, Ustiurt, and Betpak-Dala populations). A proportion of the Ustiurt population migrates south to Uzbekistan and occasionally Turkmenistan in winter. It is extinct in the People's Republic of China and southwestern Mongolia. It was hunted extensively in Romania and Moldova until it became extinct in those regions at the end of the 18th century. The Mongolian subspecies (S. t. mongolica) is found only in western Mongolia.[3][4]

Taxonomy and phylogeny

The scientific name of the saiga is Saiga tatarica. It is the sole extant member of its genus and is classified in the family Bovidae.[5] This species was first described by Swedish zoologist Carl Linnaeus in the 12th edition of Systema Naturae (1766). Linnaeus gave it the name Capra tatarica.[6] The relationship between the saiga and the Tibetan antelope (Pantholops hodgsonii) has long been debated. English zoologist Reginald Innes Pocock classified them under different subfamilies in 1910.

In 1945, American paleontologist George Gaylord Simpson classified both in the tribe Saigini under the same subfamily, Caprinae. Subsequent authors were not certain about the relationship between the two, till phylogenetic studies in the 1990s revealed that though morphologically similar, the Tibetan antelope is closer to the Caprinae while the saiga is closer to the Antilopinae.[7]

In a revision of the phylogeny of the tribe Antilopini on the basis of nuclear and mitochondrial data in 2013, Eva Verena Bärmann (of the University of Cambridge) and colleagues showed that the saiga is sister to the clade formed by the springbok (Antidorcas marsupialis) and the gerenuk (Litocranius walleri).[8] The study noted that the saiga and the springbok could be considerably different from the rest of the antilopines; a 2007 phylogenetic study suggested that the two form a clade sister to the gerenuk.[9] The cladogram below is based on the 2013 study.[8]

{{clade | style=font-size:100%;line-height:100%;width:300px;
|1={{clade
|1={{clade
|1={{clade
|1={{clade
|1={{clade
|1=Gazella
|2=Blackbuck
|2={{clade
|1=Nanger
|2=Eudorcas
             }}         }}

|2={{clade
|1=Springbok
|2=Gerenuk
         }}      }}   }}

|2=Saiga

}}}}

Two subspecies are recognised:[1][5][10]

  • S. t. mongolica Bannikov, 1946: Also known as the Mongolian saiga, it is sometimes treated as an independent species, or as subspecies of S. borealis; it is confined to Mongolia.
  • S. t. tartarica (Linnaeus, 1766): Also known as the Russian saiga, it occurs in central Asia.

Evolution

Fossils of saiga, concentrated mainly in central and northern Eurasia, date to as early as the late Pleistocene (nearly 0.1 Mya).[11] An extinct species of Saiga, S. borealis, has been identified from the Pleistocene of northern Eurasia.[12] Fossils excavated from the Buran Kaya III site (Crimea) date back to the transition from Pleistocene to Holocene.[13] The morphology of saiga does not seem to have changed significantly since prehistoric times.[2]

Before the Holocene, the saiga ranged from as far west as modern-day England and France to as far east as northern Siberia, Alaska, and probably Canada. The antelope gradually entered the Urals, though it did not colonise southern Europe. A 2010 study revealed that a steep decline has occurred in the genetic variability of the saiga since the late Pleistocene-Holocene, probably due to a population bottleneck.[14]

Characteristics

The saiga stands {{Convert|61|–|81|cm|in|abbr=on}} at the shoulder, and weighs {{convert|26|–|69|kg|lb|abbr=on}}. The head-and-body length is typically between {{Convert|100|and|140|cm|in|abbr=on}}. A prominent feature of the saiga is the pair of closely spaced, bloated nostrils directed downward. Other facial features include the dark markings on the cheeks and the nose, and the {{convert|7|–|12|cm|in|abbr=on}} long ears.[2][15] During summer migrations, a saiga's nose helps filter out dust kicked up by the herd and cools the animal's blood. In the winter, it heats up the frigid air before it is taken to the lungs.{{citation needed|date=April 2016}}

The coat shows seasonal changes. In summer, the coat appears yellow to red, fading toward the flanks. The Mongolian saiga can develop a sandy colour. The coat develops a pale, grayish-brown colour in winter, with a hint of brown on the belly and the neck. The ventral parts are generally white. The hairs, that measure {{convert|18|–|30|mm|in|abbr=on}} long in summer, can grow as long as {{convert|40|–|70|mm|in|abbr=on}} in winter. This forms a 12– to 15-cm-long mane on the neck. Two distinct moults can be observed in a year, one in spring (April to May) and another in autumn (late September or early October to late November or early December). The tail measures {{convert|6|–|12|cm|in|abbr=on}}.[2][10]

Only males possess horns. These horns, thick and slightly translucent, are wax-coloured and show 12 to 20 pronounced rings. With a base diameter of {{convert|25|–|33|mm|in|abbr=on}}, the horns of the Russian saiga measure {{convert|28|–|38|cm|in|abbr=on}} in length; the horns of the Mongolian saiga, however, reach a maximum length of {{convert|22|cm|in|abbr=on}}.[2][10]

Ecology and behaviour

Saigas form very large herds that graze in semideserts, steppes, grasslands, and possibly open woodlands, eating several species of plants, including some that are poisonous to other animals. They can cover long distances and swim across rivers, but they avoid steep or rugged areas. The mating season starts in November, when stags fight for the acceptance of females. The winner leads a herd of five to 50 females.{{Citation needed|date=July 2015}} In springtime, mothers come together in mass to give birth.{{r|gjunesaiga}} Two-thirds of births are twins; the remaining third of births are single calves.{{Citation needed|date=July 2015}}

Saigas, like the Mongolian gazelles, are known for their extensive migrations across the steppes that allow them to escape natural calamities.[16]

Saigas are highly vulnerable to wolves. Juveniles are targeted by foxes, steppe eagles, golden eagles, dogs, and ravens.[2]

Habitat and distribution

During the last glacial period, the saigas ranged from the British Isles through Central Asia and the Bering Strait into Alaska and Canada's Yukon and Northwest Territories. By the classical age, they were apparently considered a characteristic animal of Scythia, judging from the historian Strabo's description of an animal called the kolos that was "between the deer and ram in size" and was (understandably but wrongly) believed to drink through its nose.[17]

Considerable evidence shows the importance of the antelope to Andronovo culture settlements. Illustrations of saiga antelopes can be found among the cave paintings that were dated back to seventh to fifth century BC. Moreover, saiga bones were found among the remains of other wild animals near the human settlements.[18] The fragmented information shows an abundance of saigas on the territory of modern Kazakhstan in the 14th-16th centuries. The migratory routes ranged throughout the country's area, especially the region between the Volga and Ural Rivers was heavily populated.[19] The population's size remained high until the second half of the 19th century, when excessive horn export began. The high price and demand for horns drove radical hunting. The number of animals decreased in all regions and the migratory routes shifted southward.[20]

After a rapid decline, they were nearly completely exterminated in the 1920s, but they were able to recover. By 1950, two million of them were found in the steppes of the USSR. Their population fell drastically following the collapse of the USSR due to uncontrolled hunting and demand for horns in Chinese medicine. At one point, some conservation groups, such as the World Wildlife Fund, encouraged the hunting of this species, as its horn was presented as an alternative to that of a rhinoceros.[21]

Today, the populations have again shrunk enormously — as much as 95% in 15 years.[22] The saiga is classified as critically endangered by the IUCN. An estimated total number of 50,000 saigas survives today in Kalmykia, three areas of Kazakhstan, and in two isolated areas of Mongolia. Another small population in the Pre-Caspian region of Russia remains under extreme threat.[23]

Cherny Zemli Nature Reserve was created in Russia's Kalmykia Republic in the 1990s to protect the local saiga population. Kalmykia's president Kirsan Ilyumzhinov announced 2010 as the Year of Saiga in Kalmykia. In Kazakhstan, the number of saigas was found to be increasing, from around 21,000 at the beginning of this millennium to around 81,000 in January 2010.{{citation needed|date=December 2012}} However, in May 2010, an estimated 12,000 of the 26,000 saiga population in the Ural region of Kazakhstan have been found dead. Although the deaths are currently being ascribed to pasteurellosis, an infectious disease that strikes the lungs and intestines, the underlying trigger remains to be identified.[24] In May 2015, what may be the same disease broke out in three northern regions of the country.[25] As of 28 May 2015, more than 120,000 saigas have been confirmed dead in the Betpak-Dala population in central Kazakhstan, representing more than a third of the global population.[26] By April, 2016, the saigas appear to be making a comeback, with an increase of population from 31,000 to 36,000 in the Betpak-Dala area.[27]

Kazakhstan in November 2010 reaffirmed a ban on hunting saiga antelopes, and extended this ban until 2021, as the Central Asian nation seeks to save the endangered species.[28]

The Mongolian saiga (S. t. mongolica) is found in a small area in western Mongolia around the Sharga and Mankhan Nature Reserves.[29]

Currently, only the Moscow Zoo and Askania-Nova keep saigas.[30] Cologne Zoological Garden and San Diego Zoo had them in the past. Pleistocene Park in northern Siberia plans to introduce the species.

Threats and conservation

The horn of the saiga antelope is used in traditional Chinese medicine and can sell for as much as US$150.[31] Demand for the horns has wiped out the population in China, where the saiga antelope is a class I protected species, and drives poaching and smuggling.

Under the auspices of the Convention on Migratory Species of Wild Animals, also known as the Bonn Convention, the Memorandum of Understanding (MoU) Concerning Conservation, Restoration and Sustainable Use of the Saiga Antelope was concluded and came into effect 24 September 2006.[32] The saiga's decline being one of the fastest population collapses of large mammals recently observed, the MoU aims to reduce current exploitation levels and restore the population status of these nomads of the Central Asian steppes.

In June 2014, Chinese customs at the Kazakh border uncovered 66 cases containing 2,351 saiga antelope horns, estimated to be worth over Y70.5 million (US$11 million).[33] At that price, each horn would cost over US$4,600.

In June 2015, E.J. Milner-Gulland (chair of Saiga Conservation Alliance) said, "Antipoaching needs to be a top priority for the Russian and Kazakh governments."{{r|gjunesaiga}}

Hunting saiga

Saigas have been a target of hunting since prehistoric ages, when hunting was an essential means to acquire food. Saigas' horns, meat, and skin have commercial value and are exported from Kazakhstan.

Saiga horn, known as cornu antelopis, is one of the main ingredients in traditional Chinese medicine that is used as an extract or powder additive to the elixirs, ointments, and drinks. Saiga horn's value is equal to rhinoceros horn, whose trade was banned in 1993. Cornu antelopis is thought to be a cheaper substitute of rare rhino horn in most TCM recipes.[34] Although the hunting and trade is considered illegal, the horn products still can be found sold publicly and openly in a great variety of venues and businesses.[35]

Saiga meat is compared to lamb, it is considered to be nutritious and delicious. Numerous recipes for cooking the antelope's meat can be found.[36] In the period from 1955 to 1989, over 87 thousand tonnes of meat were collected in Kazakhstan by killing more than five million saiga.[37] Both meat and byproducts are sold in the country and outside of it. About 45–80 dm² of skin can be yielded from one individual depending on its age and sex.[20] The skin is used to produce suede and box calf.

Physical barriers

Agricultural advancement and human settlements have been shrinking habitat areas of the saigas since the 20th century.[20] Occupants limited saiga's passage to water resources and the winter and summer habitats. The ever-changing face of steppe requires saigas to search for new routes to their habitual lands. Currently, saiga populations' migratory routes pass five countries and different man-made constructions, such as railways, trenches, mining sites, and pipelines.[20] These physical barriers limit movement of the antelopes. Cases of saiga herds being trapped within fenced areas and starving to death have been reported.[38] Starting in 2011, Kazakhstan has built more than 150 km of wire fence at the border with Uzbekistan. This fence limits seasonal migration of saigas and other smaller animals.[39] Although concerns have been stated, the fences are still being built.

Climatic variability

Saigas are dependent on weather and affected by climate fluctuations to a great extent due to their migratory nature.[40] Harsh winters with strong winds or high snow coverage disable feeding on the grass under the thick snow. Population size usually dramatically decreases after severe cold months.[20] Recent trends in climate change lead to increasing aridity of the steppe region, thus, deficiency of the grazing pastureland. An estimate of 14% or more of available pastureland is considered degraded and useless.[41] Consequently, small steppe rivers dry faster, limiting water resources to large lakes and rivers, which are usually populated by human settlements.[20] Moreover, high temperatures in the steppe region lead to springtime floods, in which saiga calves can drown.[20]