Tara and Lali, Jukani Wildlife Sanctuary's two Siberian tigers, are the largest cat of all the cat species - adult males can weigh up to 380kg! Their arrival at Jukani Predator Park was filmed by Bush Radar's Michelle Garforth and her crew, and they have since developed a real celebrity attitude.
The Siberian tiger Panthera tigris altaica, also known as the Amur tiger, is a tiger subspecies inhabiting mainly the Sikhote Alin mountain region with a small subpopulation in southwest Primorye province in the Russian Far East. In 2005, there were 331–393 adult-subadult Amur tigers in this region, with a breeding adult population of about 250 individuals. The population has been stable for more than a decade due to intensive conservation efforts, but partial surveys conducted after 2005 indicate that the Russian tiger population is declining.
Phylogeographic analysis with extant tiger subspecies suggests that less than 10,000 years ago the ancestor of Amur and Caspian tigers colonized Central Asia via the Gansu−Silk Road corridor from eastern China then subsequently traversed Siberia eastward to establish the Amur tiger population in the Russian Far East.
The Siberian tiger is reddish-rusty or rusty-yellow in colour, with narrow black transverse stripes. The body length is not less than 150 cm (59 in), condylobasal length of skull 250 mm (9.8 in), zygomatic width 180 mm (7.1 in), and length of upper carnassial tooth over 26 mm (1.0 in) long. It has an extended supple body standing on rather short legs with a fairly long tail. It is typically 5–10 cm (2.0–3.9 in) taller than the Bengal tiger, which is about 107–110 cm (42–43 in) tall.
Measurements of more than fifty captured individuals suggest that body size is similar to that of Bengal tigers.
The ground colour of Siberian tigers' pelage is often very pale, especially in winter coat. However, variations within populations may be considerable. Individual variation is also found in form, length, and partly in colour, of the dark stripes, which have been described as being dark brown rather than black. The fur of the Siberian tiger is moderately thick, coarse and sparse compared to that of other felids living in the former Soviet Union. Compared to the now-extinct westernmost populations, the Far Eastern Siberian tiger's summer and winter coats contrast sharply with other subspecies. Generally, the coat of western populations was brighter and more uniform than that of the Far Eastern populations. The summer coat is coarse, while the winter coat is denser, longer, softer, and silkier. The winter fur often appears quite shaggy on the trunk, and is markedly longer on the head, almost covering the ears.
Distribution and habitat
The geographical range of Amur tigers in the Russian Far East stretches south to north for almost 1,000 km (620 mi) throughout the length of Primorsky Krai and into southern Khabarovsk Krai east and south of the Amur River. They also occur within the Eastern Manchurian mountain system, which crosses into Russia from China at several places in southwest Primorye. In both regions, peaks are generally 500 to 800 m (1,600 to 2,600 ft) above sea level, with only a few reaching 1,000 m (3,300 ft) or more. This region represents a merger zone of two bioregions: the East Asian coniferous-decidous complex and the northern boreal complex, resulting in a mosaic of forest types that vary with elevation, topography and past history. Key habitats for the Amur tiger are Korean pine broadleaf forests with a complex composition and structure. The ungulate complex is represented by red deer, wild boar, sika deer, roe deer, Manchurian moose, musk deer and ghoral.
The number of Amur tigers in China is estimated at 18–22, and it is not known if any still survive in North Korea. In 2005, there were 331–393 Amur tigers in the Russian Far East, comprising a breeding adult population of about 250, fewer than 100 likely to be sub-adults, more than 20 likely to be less than 3 years of age. More than 90% of the population occurs in the Sikhote Alin mountain region.
Ecology and behaviour
Siberian tigers are known to travel up to 1,000 km (620 mi), a distance that marks the exchange limit over ecologically unbroken country.
In 1992 and 1993, the maximum total population density of the Sikhote-Alin tiger population was estimated at 0.62 individuals in 100 km2 (39 sq mi). The maximum adult population estimated in 1993 reached 0.3 individuals in 100 km2 (39 sq mi), with a sex ratio of averaging 2.4 females per male. These density values were dramatically lower than what had been reported for other subspecies at the time.
Between January 1992 and November 1994, 11 tigers were captured, fitted with radio-collars and monitored for more than 15 months in the eastern slopes of the Sikhote-Alin mountain range. Results of this study indicate that their distribution is closely associated with distribution of red deer. Distribution of wild pigs was not as strong a predictor of tiger distribution. Although they prey on both Siberian roe deer and sika deer, overlap of these ungulates with tigers was low. Distribution of moose was poorly associated with tiger distribution. The distribution of preferred habitat of key prey species was an accurate predictor of tiger distribution.
In 2004, dramatic changes in land tenure, density, and reproductive output in the core area of the Sikhote-Alin Zapovednik Siberian Tiger Project were detected, suggesting that when tigers are well protected from human-induced mortality for long periods, female adult density may increase dramatically. When survivorship of adult females was high, the mothers divided their territories with their daughters once the daughters reached maturity. By 2007, density of tigers was estimated at 0.8±0.4 individuals in 100 km2 (39 sq mi) in the southern part of Sikhote-Alin Zapovednik, and 0.6±0.3 individuals in 100 km2 (39 sq mi) in the central part of the protected area.
Prey species include Manchurian wapiti, musk deer, goral and smaller prey like hares, rabbits, pikas and salmon.
Interspecific predatory relationships
Tigers may prey on both brown and black bears when ungulate populations decrease. From 1944 to 1950, only 17 instances of tiger attacking bears were recorded in the Russian Far East. They most typically attack brown bears near the hibernaculum in the winter. Brown bears are attacked by tigers more often than black bears, due to their habit of living in more open areas and their inability to climb trees. When hunting bears, tigers will position themselves from the leeward side of a rock or fallen tree, waiting for the bear to pass by. When the bear passes, the tiger will spring from an overhead position and grab the bear from under the chin with one fore paw and the throat with the other. The immobilized bear is then killed with a bite to the spinal column. After killing a bear, the tiger will concentrate its feeding on the bear's fat deposits, such as the back, hams and groin. While tigers can successfully hunt bears, there are also records of brown bears killing tigers, either in disputes over prey or in self defense, and in at least one instance, of a bear consuming a tiger.
Siberian tigers reach sexual maturity at four years of age. They mate at any time of the year. A female signals her receptiveness by leaving urine deposits and scratch marks on trees. She will spend 5 or 6 days with the male, during which she is receptive for three days. Gestation lasts from 3 to 3½ months. Litter size is normally two or four cubs but there can be as many as six. The cubs are born blind in a sheltered den and are left alone when the female leaves to hunt for food. Cubs are divided equally between genders at birth. However, by adulthood there are usually two to four females for every male. The female cubs remain with their mothers longer, and later they establish territories close to their original ranges. Males, on the other hand, travel unaccompanied and range farther earlier in their lives, making them more vulnerable to poachers and other tigers.
A broad genetic sampling of 95 wild Russian tigers found markedly low genetic diversity, with the effective population size extraordinarily low in comparison to the census population size, with the population behaving as if it were just 27–35 individuals. Further exacerbating the problem is that more than 90% of the population occurs in the Sikhote Alin mountain region, and there is little movement of tigers across the development corridor, which separates this sub-population from the much smaller sub-population found in southwest Primorye province.
The winter of 2006–2007 was marked by heavy poaching. Poaching of tigers and their wild prey species is considered to be driving the decline, although heavy snows in the winter of 2009 could have biased the data.
Threats in the past
In the early years of the Russian Civil War, both Red and White armies based in Vladivostok nearly wiped out the local Siberian tigers. In 1935, when the Manchurian Chinese were driven back across the Amur and the Ussuri, the tigers had already withdrawn from their northern and western range. The few that remained in the East Manchurian mountains were cut off from the main population by the building of railroads. Within a few years, the last viable Siberian tiger population in Russia was confined to Ussuriland. Legal tiger hunting within the Soviet Union would continue until 1947 when it was officially prohibited. In the mid 1980s, it was estimated that the Siberian tiger population consisted of approximately 250 animals. In 1987, law and order almost entirely broke down due to the impending dissolution of the Soviet Union. Subsequent illegal deforestation and bribery of park rangers made the poaching of Siberian tigers easier, once again putting the subspecies at risk from extinction.
Decades of development and war have destroyed the population in Korea. Heat sensing camera traps set up in the Demilitarized Zone in South Korea did not record any tigers.
Tigers are included on CITES Appendix I, banning international trade. All tiger range states and countries with consumer markets have banned domestic trade as well. At the 14th Conference of the Parties to CITES in 2007, stronger enforcement measures were called for, as well as an end to tiger farming.
In 1992, the Siberian Tiger Project was founded, with the aim of providing a comprehensive picture of the ecology of the Amur tiger and the role of tigers in the Russian Far East through scientific studies. By capturing and outfitting tigers with radio collars, their social structure, land use patterns, food habits, reproduction, mortality patterns and their relation with other inhabitants of the ecosystem, including humans is studied. These data compilations will hopefully contribute toward minimizing poaching threats due to traditional hunting. The Siberian Tiger Project has been productive in increasing local capacity to address human-tiger conflict with a Tiger Response Team, part of the Russian government’s Inspection Tiger, which responds to all tiger-human conflicts; by continuing to enhance the large database on tiger ecology and conservation with the goal of creating a comprehensive Siberian tiger conservation plan; and training the next generation of Russian conservation biologists.
In August 2010, China and Russia agreed to enhance conservation and cooperation in protected areas in a transboundary area for Amur tigers. China has undertaken a series of public awareness campaigns including celebration of the first Global Tiger Day in July 2010, and International Forum on Tiger Conservation and Tiger Culture and China 2010 Hunchun Amur Tiger Culture Festival in August 2010.
Attacks on humans
Unlike the Bengal tiger, the Siberian tiger very rarely becomes a man-eater. Several cases of attacks on humans were recorded in the 19th century, occurring usually in central Asia excluding Turkmenistan, Kazakhstan and the Far East. Siberian tigers were historically rarely considered dangerous unless provoked.
The Tungusic people considered the Siberian tiger a near-deity and often referred to it as "Grandfather" or "Old man". The Udege and Nanai called it "Amba". The Manchu considered the Siberian tiger as Hu Lin, the king. The most elite unit of the Chinese Imperial Army in Manchu Qing Dynasty is called Hu Shen Ying, literally The Tiger God Battalion.
Did you know?
In the 1940s the Amur tiger was on the brink of extinction, with no more than 40 tigers remaining in the wild. Thanks to vigorous anti-poaching and other conservation efforts by the Russians with support from many partners, including WWF, the Amur tiger population recovered and has remained stable throughout the last decade.