Captive Caspian tiger at the Berlin Zoo, 1899
|Common Name||Hyrcanian Tiger and Turan Tiger|
|Range||South of the Caspian Sea, from Turkey, Iran and East through Central Asia into the Takla Makan desert of Xinjiang, China.|
The Caspian tiger, also known as the Hyrcanian tiger and the Turan tiger, (Panthera tigris virgata) is an extinct tiger subspecies that had been recorded in the wild until the early 1970s, and used to inhabit the sparse forest habitats and riverine corridors west and south of the Caspian Sea, from Turkey, Iran and east through Central Asia into the Takla Makan desert of Xinjiang, China. There are no individuals in captivity. The Caspian tiger was formerly found in Chinese and Russian Turkestan, Afghanistan, Iran, and Turkey.
The body of Caspian tigers was generally less massive than of Siberian tigers, and their average size slightly less. In Turkestan, male tigers exceeded 200 cm (79 in) in length, though an estimated body length of 270 cm (110 in) was recorded. Females were smaller in size, normally ranging between 160 to 180 cm (63 to 71 in). The maximum known weight was 240 kg (530 lb). Maximum skull length in males was 297.0 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). Although tigers from Turkestan never reached the size of Siberian tigers, there are records of very large individuals. In January 1954, a tiger killed near the Sumbar River in Kopet-Dag had a skull length of 385 mm (15.2 in), which is considerably more than the known maximum for this population and slightly exceeds that of most Siberian tigers.
The main background colour of its pelage varied, though generally it was brighter and more uniform than that of Far Eastern tigers. The stripes were narrower, fuller and more closely set than those of the Siberian tiger. The colour of its stripes were a mixture of brown or cinnamon shades. Pure black patterns were invariably found only on the 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 the 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.
Phylogenetic relationship to 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 observed 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 Amur tiger indicating that the Amur tiger population is the genetically closest living relative of the extinct Caspian tiger, and strongly implying a very recent common ancestry for the two groups. 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 Amur 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 Amur 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.
Of all tiger subspecies, Amur tigers are most suited for potential reintroduction to the former range of the Caspian tiger.
Distribution and habitat
Historical records show that the distribution of Caspian tigers 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, they occurred:
- in the extreme southeast of the Caucasus : 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; and in the Zangezur Mountains of northwestern Iran;
- in Middle Asia : in 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; along the Syr-Darya to the Fergana Valleyas far as Tashkent and the western spur of Talas Alatau; along the entire coast of the Aral Sea; along the Chu and Ili Rivers; all along the southern shore of Lake Balkhash, and northwards into the southern Altai Mountains.
Their 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 end of the Caspian 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.
No data are available for home ranges of Caspian tigers. In search of prey, Caspian tigers were compelled to prowl widely and follow ungulates from one pasture to another. Wild pigs and cervids formed their main prey base. In many regions of Middle Asia, Bactrian deer and roe deer were important prey species apart from wild pigs. Occasionally, they also preyed on Caucasian red deer, goitered gazelle in Iran, Eurasian golden jackals, jungle cats, locusts, and other small mammals in the lower Amu-Darya River area, and on 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, and on Manchurian wapiti and moose in the Baikal area. They followed herds of migratory prey species such as reindeer, and 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.
The demise of the Caspian tiger began with the Russian colonisation of Turkestan during the late 19th century. Their extirpation was a process intensified by several circumstances:
- They were ruthlessly persecuted by large parties of sportsmen and military personnel who hunted wild pigs and tigers with reckless abandon.
- 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, which were used as highways for colonisation of riverine habitat.
- The range of wild pigs underwent intense shrinkage between the middle of the 19th century and the 1930s due to thoughtless hunting, natural calamities such as floods and fires, and diseases such as swine fever and foot-and-mouth disease, which caused large and rapid die-offs.
- Tigers were already vulnerable due to the restricted nature of their distribution, having been confined to watercourses in 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. Wild pigs and deer, the prey base of the tigers, were decimated by deforestation and subsistence hunting by the increasing human population along the rivers, supported by the 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.
The last Caspian tigers
In Iraq, the only reported Caspian tiger was killed near Mosul in 1887. The last known tiger in the Caucasus region was killed in 1922 near Tbilisi, Georgia, after taking domestic livestock. They disappeared from the Tarim River basin in Xinjiang in the 1920s. In Kazakhstan, the last tiger was recorded in 1948 in the environs of the Ili River, their last stronghold in the region of Lake Balkhash. In Turkmenistan, the last tiger was killed in January 1954 in the valley of the Sumbar River in the Kopet-Dag Range. In Iran's Golestān Province, one of the last tigers was shot in 1953; one individual was sighted in the area in 1958. In the Tian Shan mountains west of Ürümqi in China, the last Caspian tigers disappeared from the Manasi River basin in the 1960s. The last record from the lower reaches of the Amu-Darya river near the Aral Sea was an unconfirmed observation near Nukus in 1968. By the early 1970s, tigers disappeared from the river’s lower reaches and the Pyzandh Valley in the Turkmen-Uzbek-Afghan border region.
There are claims of a documented killing of a tiger at Uludere, Hakkari in Turkey in 1970. Questionnaire surveys conducted in southeastern Turkey revealed one to eight tigers were killed each year in eastern Turkey until the mid-1980s, and 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.
Last efforts to save Caspian tigers from extinction
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 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 River near the border of Afghanistan. The last Caspian tiger was seen there in 1958.
Since 1947, tigers were legally protected in the USSR.
In Iran, Caspian tigers have been protected since 1957, with heavy fines for shooting. In the early 1970s, biologists from the Iran Department of the Environment searched several years for Caspian tigers in the uninhabited areas of Caspian forests, but did not find any evidence of their presence.