A camera trap in Russia has recorded the sound of the world's rarest big cat in the wild for the first time in history.
The footage of the critically endangered Amur Leopard – of which there are fewer than 100 left – was captured in a protected area known as Leopard Land National Park, which spans nearly 300,000 hectares and is home to the world's only documented wild population of the animal.
In the video, a seven-year-old male named Typhoon can be seen entering the shot while making a distinctive vocalisation that the leopards use to stake out their territory.
While there are more than 300 camera traps dotted through the protected area, until last year, they were not equipped with sound recording capabilities.
"We were able to record this sound for the first time," said Victor Storozhuk, a researcher Leopard Land's science department. "Now everyone can learn more about the rarest big cat."
Due to successful conservation initiatives, which have included the suppression of poaching activities and effective winter feeding strategies, the number of Amur leopards has more than doubled in 10 years from 30 to 70 individuals.
Scientists at the park use the camera traps – which turn on automatically when they sense movement – to study the animals. The captured footage can help to gauge numbers, determine the boundaries of their habitat and gather information on their lifestyle, including the relationships between individual leopards.