It's been called the "Serengeti of the north": The world's largest intact natural grasslands stretch across Central Asia, linking up with deserts, forests and mountain ranges. Roaming for thousands of miles across these varied landscapes are a host of unique migratory animals, many of them found nowhere else on earth.

These include the snow leopard, the rare Persian leopard, Argali sheep, saiga and Tibetan antelopes, and the critically endangered wild Bactrian camel.

In fact, Polina Orlinskiy - coordinator of the Convention on the Conservation of Migratory Species of Wild Animals' (CMS) Central Asian Mammals Initiative - says if anything, the comparison with the east African national park undersells just how unique and spectacular these relatively unknown ecosystems are.

"The Central Asian deserts and grasslands are huge - much, much bigger than the Serengeti," Orlinskiy told DW.

Central Asia's beautiful landscapes are still largely unaffected by human settlements, Orlinskiy said. That includes "many different plants, endemic species, grasslands, mountains, lakes, forests and very, very diverse and still interconnected ecosystems, where wild animals can roam freely for thousands of kilometers."

The main threat to the saiga antelope is from hunters, who supply parts of the animal to the Chinese medicine trade

Modern travel disrupts ancient routes

With much of Central Asia sparsely populated, migratory animals have long made their epic yearly journeys with little interference from humans. But this is also a region that bridges East and West.

The site of the ancient Silk Road trading route, today Central Asia is traversed by a growing network of roads and railways. And these human-made travel routes are disrupting the much older ones used by camels, asses and antelopes.

"The trans-Mongolian railway is very busy transporting goods between China and Russia, and also further into Europe," Orlinskiy explains. "It has barbed wire on both sides, which a lot of migratory animals, such as Mongolian gazelles, Kuhlan [Asiatic wild ass] and Argali sheep cannot cross."

Earlier this year, thousands of gazelles died because they were unable to cross the railway from snow-covered areas into territory that would have provided them with better access to food in the winter months.

Animals don't respect national borders

And even national borders can cause problems for animals whose range stretches across different countries.

"The gazelles' former range included Mongolia, parts of China and Russia," said Thomas Mueller, a junior professor of movement ecology and biodiversity conservation at Senckenberg Biodiversity and Climate Research Center in Germany.

"These countries currently have only small numbers of gazelle living within their borders - but border fencing is preventing connectivity among these populations."

That's why the United Nations Environment Program's CMS Central Asian Mammals Initiative is working to build international efforts to protect 15 mammal species - which are either migratory or regularly cross international borders - across an area that encompasses parts of Russia, Kazakhstan, Turkmenistan, Iran, Afghanistan, Tajikistan, Mongolia, China, Bhutan, Nepal and Pakistan.

"Migratory mammals need space," said Petra Kaczensky of the University of Veterinary Medicine in Vienna. Kaczensky is working on efforts to protect the Khulan, which can have a range of up to 70,000 square kilometers (27,000 square miles.

"They don't recognize international borders - and they can't fly!"

Working with local communities

The Central Asian Mammals Initiative works with local partners to shape infrastructure development with an eye of the needs of migratory animals. Simply taking down fences can be one solution - or providing under- or overpasses to allow animals to cross roads and railways.

But this often raises issues of competing interests, such as local farmers' concerns over safety of their livestock if fences are taken down to allow other animals across. Orlinskiy stresses it's important to take the needs of local communities into account.

Working with the national governments, measures such as community-based species management, encouraging ecotourism and spreading awareness of the importance of conservation all play a role, she points out.

Climate change ups pressure

Finding such solutions is becoming an increasingly urgent, as climate change puts additional pressures on Central Asian wildlife.

The Mongolian gazelle's range stretches into Russia and China, but in Mongolia hunting has cut numbers in half

"In dry ecosystems, there are changing patterns of rainfall and vegetation growth," Orlinskiy explained. "Animals are able to adapt to that if they are able to move freely and find the resources they need."

"But if there is a lot of construction going on - roads creating a physical barrier in their path - of course they are hindered in their ability to adapt to climate change."

Competing with humans

Disrupted migratory routes aren't the only threat. A rising human population also means that Central Asia's wild grazers are increasingly in competition with livestock, and at risk from diseases that can spread from domestic animals to wild species.

And most of the 15 species are also under threat from poaching - whether by impoverished communities that hunt them for food, or for international trade. Like at the Serengeti, wildlife trafficking is also a problem for Central Asian animals.

"The major threat for saiga antelopes is poaching throughout all populations in all range states," said Steffen Zuther of the Association for the Conservation of Biodiversity of Kazakhstan.

"Males are killed for their horns, which are used in traditional Chinese medicine - similar to rhino horns, which can be sold at high prices."