(ECNS) -- An infrared camera set up in a National Wetland Park in Inner Mongolia captured an otter wandering along an "ice-free" river in winter.
In the video, the otter swam into the river to feed, rolled on the ice to shake water off its body, and ran to the riverbank in search of hay.
The otter's search for hay during the day is unusual and monitors speculated that the nocturnal animal's move is for thickening its nest due to the recent extreme cold.
After years of continuous monitoring and study of otters' living habits, researchers at the Wetland Park found that otters build temporary nests near the water region rich in food in winter, which is convenient for them to rest in their caves during the day and forage at night.
Listed on the IUCN Red List of Threatened Species in 2015, the otter is a second-class protected animal in China.