The saiga antelope (, Saiga tatarica), or saiga, is an antelope which is critically endangered, and during antiquity inhabited a vast area of the Eurasian steppe, spanning the foothills of the Carpathian Mountains in the northwest and Caucasus in the southwest, into Mongolia in the northeast and Dzungaria in the southeast. During the Pleistocene, they ranged across the mammoth steppe from the British Isles to Beringian North America. Today, the dominant subspecies (S. t. tatarica) is only found in one region in Russia (in the Republic of Kalmykia and Astrakhan Oblast) and three areas in Kazakhstan (the Ural, Ustiurt, and Betpak-Dala populations). A portion of the Ustiurt population migrates south to Uzbekistan and occasionally Turkmenistan in winter. Notable for a distinctively large proboscis amongst its kind, it is extirpated from China, Ukraine, and southwestern Mongolia. The Mongolian subspecies (S. t. mongolica) is found only in western Mongolia.
Taxonomy and phylogeny
The scientific name Capra tatarica was coined by Carl Linnaeus in 1766 in the 12th edition of Systema Naturae. It was reclassified as Saiga tatarica and is the sole living member of the genus Saiga. Two subspecies are recognised: S. t. tatarica (Linnaeus, 1766): also known as the Russian saiga, it occurs in central Asia. S. t. mongolica Bannikov, 1946: also known as the Mongolian saiga, it is sometimes treated as an independent species, or as subspecies of the Pleistocene Saiga borealis; it is confined to Mongolia.
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, until 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.
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). 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. The cladogram below is based on the 2013 study.
Evolution
Fossils of saiga, concentrated mainly in central and northern Eurasia, date to as early as the late Pleistocene (nearly 0.1 Mya). Several species of extinct Saiga from the Pleistocene of Eurasia and Alaska have been named, including S. borealis, S. prisca, S. binagadensis and S. ricei, although more recent studies suggest that these prehistoric representatives were merely geographical variants of the extant species that was formerly much more widespread. Fossils excavated from the Buran Kaya III site (Crimea) date back to the transition from Pleistocene to Holocene. The morphology of saiga does not seem to have changed significantly since prehistoric times.
Before the Holocene, the saiga ranged across the mammoth steppe 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.
Characteristics
The saiga stands at the shoulder, and weighs . The head-and-body length is typically between . 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 long ears. 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.
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 long in summer, can grow as long as in winter. This forms a 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 .