Everyone on social media is talking about China's "magic bunny", the cutest endangered animal that you have never heard of.

Sixty-year-old retired conservationist Li Weidong has been on a mission for over 30 years to document and protect the highly-endangered Ili Pika - a mysterious rabbit-like mammal only found in China. With less than 1,000 left they are now rarer than pandas.

Li first spotted the "magic bunny" in 1983.

He remembers his first encounter vividly. "I had been climbing a mountain for four hours, and was just catching my breath, when suddenly, I saw the shadow of a small creature running by."

"I sat down next to some rocks, and suddenly two bunny ears emerged from the crack of one of the rocks. The little thing was staring at me, blinking at me. I thought it was the most beautiful and bizarre creature I'd ever seen. I couldn't believe my eyes."

At the time Li was working on disease prevention. He was not looking to discover a new species.

There are many different kinds of pikas - small rabbit-like mammals with short limbs and round ears - but unlike other pikas, the one Li spotted had three distinct brown stripes on its forehead and around its neck.

After three years of research, Li and his team named the little creature the Ili Pika, after the area where it is found, the Ili Prefecture on the far west side of China's Xinjiang province.

New danger

Scientifically known as Ochotona iliensis, the Ili Pika live in holes between bare rocks at an altitude of 2,800m (9, 186ft) to 4,000m. They are used to living on the extremely cold plateau and feeding on herbs found in the Tian Shan mountains.

After he made the discovery, Li and his fellow conservationists decided to take measures to protect the pikas. But they did not want any publicity.

They thought it was better to leave the pikas alone in their natural habitat.

The natural prey of foxes, weasels and birds, the Ili Pika now face a new danger.

In the past 30 years, their habitat has shrunk by 71%, Li said. This is partly because of climate change and partly because their grazing area has been taken over by a growing population of people at the bottom of the mountain.

"The Ili Pikas all live on isolated mountain tops, so their habitats are highly fragmented," Li explains. "Losing even one is detrimental for the entire group."

Li saw the mysterious pika a few more times including in 1990. But then he did not see one again for 24 years.

Ancient species

The Ili Pika shot to fame after the National Geographic profiled it. Now it has gone viral. The sudden rise to fame worries Li.

"Many people have written to me to say they want to help me protect the pikas," he said. "But more attention also means more danger for them."

Ili Pika is an ancient species. It has been around for decades. "We cannot let them disappear in front of our eyes."