The Caspian tiger (Panthera tigris virgata) is an extinct tiger subspecies, which inhabited the sparse forests and riverine corridors west and south of the Caspian Sea, from Turkey, Mesopotamia, Iran and the Caucasus, through Central Asia to the Takla Makan desert of Xinjiang in China, until the end of the 20th century. Depending on the region of origin, it was also called Hyrcanian tiger, Turanian tiger, Persian tiger, and Babre Mazandaran (Persian: ببرِ مازندران, Tiger of Mazandaran). It was one of the biggest cats to have ever lived and was described as being intermediate in size between Siberian and Bengal tigers.
In 1815, Illiger assigned the scientific name P. t. virgata to the Caspian tiger. Genetic studies have revealed that the Caspian tiger and Siberian tiger (P. t. altaica) shared a common ancestor. In 2017, the Cat Classification Task Force of the IUCN Cat Specialist Group revised felid taxonomy and now recognizes the tiger subspecies of mainland Asia as populations of P. t. tigris.
Illustration of two Caspian tigers.
Comparative illustration of the stripe patterns on the tails of Caspian (left) and Siberian tigers (right).
Photographs of skins of Caspian and Amur tigers indicate that the main background colour of the Caspian tiger's pelage varied and was generally brighter and more uniform than that of the Siberian tiger. The stripes were narrower, fuller and more closely set than those of tigers from Manchuria. The colour of its stripes were a mixture of brown or cinnamon shades. Pure black patterns were invariably found only on head, neck, the middle of the back and at the tip of the tail. Angular patterns at the base of the tail were less developed than those of Far Eastern populations. The contrast between the summer and winter coats was sharp, though not to the same extent as in Far Eastern populations. The winter coat was paler, with less distinct patterns. The summer coat had a similar density and hair length to that of the Bengal tiger, though its stripes were usually narrower, longer and closer set. It had the thickest fur amongst tigers, possibly due its occurrence in the temperate parts of Eurasia.
The Caspian tiger, together with its surviving relatives in the Far East and Indian subcontinent, and lion, ranked among the largest Felidae that ever existed. The Caspian tiger had a less massive body than the Ussuri population of the Siberian tiger. Its average body length was around 3 metres (10 ft). Males weighed 170–240 kg (370–530 lb), whereas females weighed 85–135 kg (187–298 lb). The maximum known weight was greater than 240 kg (530 lb). Maximum skull length in males was 297 to 365.8 mm (11.69 to 14.40 in), while that of females was 195.7 to 255.5 mm (7.70 to 10.06 in). Its occiput was broader than of the Bengal tiger.
Some individuals attained exceptional sizes. In 1954, a tiger was killed near the Sumbar River in Kopet-Dag whose stuffed skin was put on display in a museum in Ashgabat. Its body length was 2.25 m (7.4 ft), its skull had a condylobasal length of about 305 mm (12.0 in), and zygomatic width of 205 mm (8.1 in), its greatest skull length was 385 mm (15.2 in), which is considerably more than the other known maximum of 365.8 mm (14.40 in) for this population, and slightly exceeds those of most Siberian tigers.
In Prishibinske, a tiger was killed in February 1899. Measurements after skinning revealed a body length of 270 cm (8.9 ft) between the pegs, plus a 90 cm (3.0 ft) long tail, giving it a total length of about 360 cm (11.8 ft). Measurements between the pegs of up to 2.95 m (9.7 ft) is known. According to Satunin it was "a tiger of immense proportions" and "no smaller than the common Tuzemna horse." It had rather long fur.
Phylogenetic relationship to the Siberian tiger
At the start of the 21st century, researchers from the University of Oxford, the U.S. National Cancer Institute and the Hebrew University of Jerusalem collected tissue samples from 23 Caspian tiger specimens kept in museums across Eurasia. They sequenced at least one segment of five mitochondrial genes and found a low amount of variability of the mitochondrial DNA in P. t. virgata as compared to other tiger subspecies. They re-assessed the phylogenetic relationships of tiger subspecies and observed a remarkable similarity between Caspian and Siberian tiger indicating that the Siberian tiger population is the genetically closest living relative of the Caspian tiger, which strongly implies a very recent common ancestry of two populations. Based on phylogeographic analysis they suggested that the ancestor of Caspian and Amur tigers colonized Central Asia via the Gansu−Silk Road region from eastern China, less than 10,000 years ago, and subsequently traversed Siberia eastward to establish the Siberian tiger in the Russian Far East. The actions of industrial age humans may have been the critical factor in the reciprocal isolation of Caspian and Siberian tigers from what was likely a single contiguous population. While conducting a geographical variation study in tigers, it was discovered that the Caspian tiger is indistinguishable from other tiger subspecies. Its skull size and shape are similar to those of the Siberian tiger.
Distribution and habitat
Historical records show that the distribution of the Caspian tiger in the region of the Caspian Sea was not continuous but patchy, and associated with watercourses, river basins, and lake edges. In the 19th century, tigers occurred in:
- the Eastern Anatolia Region, which is considered to have been the westernmost area where tigers occurred. Records are known from the region of Mount Ararat, Şanlıurfa, Şırnak, Siirt and Hakkari Provinces in eastern Turkey; in the Hakkari Province tigers possibly occurred up to the 1990s. The only confirmed record in Iraq dates to 1887 when a tiger was shot near Mosul, which is considered to have been a migrant from southeastern Turkey. There are also claims of historical tiger presence in the area of the Tigris–Euphrates river system in Iraq and Syria.
- the extreme southeast of the Caucasus, such as in hilly and lowland forests of the Talysh Mountains, in the Lenkoran Lowlands, in the lowland forests of Prishib, from where they moved into the eastern plains of the Trans-Caucasus (where Absheron is located); the Zangezur Mountains of northwestern Persia. In Iran, historical records are known only from along the southern coast of the Caspian Sea and adjacent Alborz Mountains.
- Central Asia such as southwestern Turkmenia along the Atrek River and its tributaries, Sumbar and Chandyr Rivers; in the western and southwestern parts of Kopet-Dag; in the environs of Ashkabad in the northern foothills; in Afghanistan along the upper reaches of Hari-Rud at Herat, and along the jungles in the lower reaches of the river; around Tedzhen and Murgap and along the Kushka and Kashan rivers; in the Amu-Darya basin as far the Aral Sea and along the entire coast of the Aral Sea; along the Syr-Darya to the Fergana Valley as far as Tashkent and the western spur of Talas Alatau; along the Chu and Ili Rivers; all along the southern shore of Lake Balkhash and northwards into the southern Altai Mountains, and to southeastern Transbaikal or Western Siberia in the east.
Its former distribution can be approximated by examining the distribution of ungulates in the region. Wild pigs were the numerically dominant ungulates occurring in forested habitats, along watercourses, in reed beds and in thickets of the Caspian and Aral Seas. Where watercourses penetrated deep into desert areas, suitable wild pig and tiger habitat was often linear, only a few kilometers wide at most. Red and roe deer occurred in forests around the Black Sea to the western side and around the southern side of the Caspian Sea in a narrow belt of forest cover. Roe deer occurred in forested areas south of Lake Balkash. Bactrian deer occurred in the narrow belt of forest habitat on the southern border of the Aral Sea, and southward along the Syr-Darya and Amu-Darya rivers.
Tiger killed in northern Iran, early 1940s
The demise of the Caspian tiger began with the Russian colonisation of Turkestan during the late 19th century. Its extirpation was caused by several factors:
- Tigers were killed by large parties of sportsmen and military personnel who also hunted tiger prey species such as wild pigs. The range of wild pigs underwent a rapid decline between the middle of the 19th century and the 1930s due to overhunting, natural disasters, and diseases such as swine fever and foot-and-mouth disease, which caused large and rapid die-offs.
- The extensive reedbeds of tiger habitat were increasingly converted to cropland for planting cotton and other crops that grew well in the rich silt along rivers.
- Tigers were already vulnerable due to the restricted nature of their distribution, having been confined to watercourses within the large expanses of desert environment.
Until the early 20th century, the regular Russian army was used to clear predators from forests, around settlements, and potential agricultural lands. Until World War I, about 100 tigers were killed in the forests of Amu-Darya and Piandj Rivers each year. High incentives were paid for tiger skins up to 1929. The prey base of tigers, wild pigs and deer, were decimated by deforestation and subsistence hunting by the increasing human population along the rivers, supported by growing agricultural developments. By 1910, cotton plants were estimated to occupy nearly one-fifth of Turkestan's arable land, with about one half located in the Fergana Valley.
In China, tigers disappeared from the Tarim River basin in Xinjiang in the 1920s. From the Manasi River basin in the Tian Shan Range west of Ürümqi they reportedly disappeared in the 1960s.
In Iraq, a tiger was killed near Mosul in 1887. The last known tiger in Georgia was killed in 1922 near Tbilisi, after taking domestic livestock. Its stuffed body was put on display in the Georgian National Museum.
In Kazakhstan, the last Caspian tiger was recorded in 1948, in the environs of the Ili River, the last known stronghold in the region of Lake Balkhash. In Turkmenistan, the last known tiger was killed in January 1954 in the Sumbar River valley in the Kopet-Dag Range. The last record from the lower reaches of the Amu-Darya river was an unconfirmed observation in 1968 near Nukus in the Aral Sea area. By the early 1970s, tigers disappeared from the river's lower reaches and the Pyzandh Valley in the Turkmen-Uzbek-Afghan border region.
In Golestan National Park, one of the last known Iranian tigers was shot in 1953. An individual was sighted in the Golestan area in 1958.
Several tiger skins found in the early 1970s near Uludere indicated the presence of a tiger population in eastern Turkey. Questionnaire surveys conducted in this region revealed that one to eight tigers were killed each year until the mid-1980s, and that tigers likely had survived in the region until the early 1990s. Due to lack of interest, in addition to security and safety reasons, no further field surveys were carried out in the area. A pair of tigers was allegedly killed in the area of Selçuk in 1943.
The Piandj River area between Afghanistan and Tajikistan was a stronghold of the Caspian tiger until the late 1960s. The latest sighting of a tiger in the Afghan-Tajik border area dates to 1998 in the Babatag Range.
No information is available for home ranges of Caspian tigers. In search for prey, they possibly prowled widely and followed migratory ungulates from one pasture to another. Wild pigs and cervids probably formed their main prey base. In many regions of Central Asia, Bactrian deer and roe deer were important prey species, as well as Caucasian red deer, goitered gazelle in Iran; Eurasian golden jackals, jungle cats, locusts, and other small mammals in the lower Amu-Darya River area; saiga, wild horses, Persian onagers in Miankaleh peninsula; Turkmenian kulans, Mongolian wild asses, and mountain sheep in the Zhana-Darya and around the Aral Sea; Manchurian wapiti and moose in the area of Lake Baikal. They caught fish in flooded areas and irrigation channels. In winter, they frequently attacked dogs and livestock straying away from herds. They preferred drinking water from rivers, and drank from lakes in seasons when water was less brackish.
Two tigers in southwestern Tajikistan harbored 5–7 tapeworms (Taenia bubesei) in their small and large intestines.
Parts of the tiger's range also hosted other large and small felid species, besides caniforms like the Syrian brown bear:
- The Asiatic lion occurred in the tugays and pistachio savannahs in the eastern South Caucasus, from Kurdistan, Iraq, the Syrian region and Turkey, to Armenia and northern Iran.
- The Asiatic cheetah occurred in semi-desert, desert plains and steppes east of the Caspian Sea, viz in Kazakhstan, Turkmenistan and Uzbekistan, up to elevations of 700 m (2,300 ft), and in the Middle East and the Caucasus.
Still extant species in the region include:
- The Persian leopard, which was most likely distributed over the whole Caucasus; today, it survives only in small and fragmented populations in this region.
- The jungle cat, which was recorded in wetlands bordering the Caspian Sea, in the Volga River delta and in valleys of the Terek, Kura, Aras, Amu Darya and Syr Darya rivers; in southern Turkey it is known from a few coastal and inland wetlands.
- The Turkestan sand cat, which is known from the Karakum and Kyzylkum Deserts where it was hunted for fur during the Soviet period; a contemporary record is known only from Uzbekistan.
- The Asiatic wildcat, which occurs from south-eastern Turkey, Kurdistan and the Caucasus across Central Asia to India and Mongolia in a variety of habitats.
Colour-enhanced photo of the captive Caspian tiger in the Berlin Zoo
In 1938, the first protected area Tigrovaya Balka, "tiger former river channel", was established in Tajikistan. The name was given to this zapovednik after a tiger had attacked two Russian Army officers riding horseback along a dried-up river channel called balka. Tigrovaya Balka was apparently the last stronghold of Caspian tigers in the Soviet Union, and is situated in the lower reaches of Vakhsh River between the Piandj and Kofarnihon Rivers near the border of Afghanistan. A tiger was seen there in 1958.
After 1947, tigers were legally protected in the Union of Soviet Socialist Republics.
In Iran, Caspian tigers had been protected since 1957, with heavy fines for shooting. In the early 1970s, biologists from the Department of Environment searched several years for Caspian tigers in the uninhabited areas of Caspian forests, but did not find any evidence of their presence.
Stimulated by recent findings that the Siberian tiger (Amur population) is the closest relative of the Caspian tiger, albeit slightly bigger than it, discussions started as to whether the Amur tiger could be an appropriate subspecies for reintroduction into a safe place in Central Asia. The Amu-Darya Delta was suggested as a potential site for such a project. A feasibility study was initiated to investigate if the area is suitable and if such an initiative would receive support from relevant decision makers. A viable tiger population of about 100 animals would require at least 5,000 km2 (1,900 sq mi) of large tracts of contiguous habitat with rich prey populations. Such habitat is not available at this stage and cannot be provided in the short term. The proposed region is therefore unsuitable for the reintroduction, at least at this stage.
While the restoration of the Caspian tiger has stimulated discussions, the locations for the tiger have yet to become fully involved in the planning. But through preliminary ecological surveys it has been revealed that some small populated areas of Central Asia have preserved natural habitat suitable for tigers.
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