Russian tigers and the struggle to maintain connectivity

(To read this post in Russian, click here.)

The Amur tiger (or Siberian tiger) is one of the rarest and biggest cats of the planet, with a wild population of 480–540 individuals that mostly live in the Russian Far East. Similar to other big carnivores, habitat loss and fragmentation is one of the main conservation challenges for the species. Given the intense development and construction occurring within the tiger’s range, ecological corridors may be the only possible way to keep a healthy, viable population.

Most Amur tigers inhabit Sikhote-Alin Mountains, a large range in Southeast Russia with low human density. A small part of the population also lives nearby in the Southwest Primorye Province, along the Russian-Chinese border. Unfortunately for the tigers, human and road density in Southwest Primorye is higher than in the Sikhote-Alin Mountains. Recent research has shown that the Sikhote-Alin tigers are genetically similar to each other, despite a distance of up to 500 km between individuals. At the same time, tigers from Southwest Primorye are much more different genetically, even though in some places there are only a few kilometers between animals. Why? In this region, the Razdolnaya River (which means ‘large’ or ‘spacious’ in Russian) and an area of intensive development along it prevent individuals from moving freely. Small populations are vulnerable, and genetic separation threatens them even more.

Clearly, an ecological corridor from Sikhote-Alin Mountains to Southwest Primorye would benefit wildlife, and not only tigers. This region is also home to the Amur leopard, another rare cat with a wild population of only 50-60 animals.  As with the tigers, leopards also fail to travel from Southwest Primorye to Sikhote-Alin Mountains, based on snow track surveys.

Using least cost-distance analysis, Miquelle et al. 2015 identified the most effective potential corridor, which would connect two protected areas: Ussuriskii Zapovednik and Land of the Leopard National Park. This corridor would cross the Razdolnaya River and a federal highway. The total route would run 62.5 km, with most of the corridor (93%) in forested habitats. The core area of this corridor could be designated as a regional wildlife refuge, but would cover only about 30 km².

Designation of this corridor might be challenging due to an absence of federal legislation for ecological corridors in Russia. However, several regional protected areas were recently designated  along the Russian-Chinese border to ensure habitat connectivity for tigers traveling between the two countries. Other efforts to save tiger habitats include construction of the 575 m-long Narvinsky tunnel in Primorye, Russia’s first wildlife underpass that crosses under the Razdolnoye-Hasan highway. Taken together, these efforts provide a hope for tiger habitat conservation.