Tibetan wildlife photographer Matse Rangja has been tracking snow leopards for eight years, and his efforts have paid off in a video clip that shows the elusive cat sniffing at the hidden camera's lens.

Last October, Rangja captured infrared video of snow leopards roaming the 15,000-foot Burhan Budai Mountains in China's northwest Qinghai Province at night. Last month, his camera trap caught a leopard during the daytime — and that video was released to the public this week.

"I make notice of the footprints and excrement of snow leopards when I'm on a picture trip," Rangja explained in an NTD TV report on his latest video. "And if I find the footprints, I will hide my camera nearby."

Snow leopards are on the International Union for the Conservation of Nature's Red List of Threatened Species, in large part due to poaching and human encroachment. Citing figures from 2003, the IUCN estimates that there are as many as 6,590 snow leopards left in the world, including 2,500 in China. But it acknowledges that the estimates may be "rough and out of date."

"There is no definite number in China or overseas to say how many snow leopards are left in Qinghai Province, in China or across the globe," NTD TV quoted Zhang Yu, a senior engineer in the Qinghai Department of Forestry, as saying. "We can only say that there is an average of 3.1 snow leopards every 100 square kilometers."

More views of snow leopards:

• Snow leopard moms and cubs seen in Mongolia
• Elusive snow leopards collared for science
• First snow leopards filmed in Siberia
• Snow leopards turn up in Kashmir, too

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.