The breeding season starts in March and it is the busiest time for Li and his colleagues as they need to work extra hours to take care of the animals until mid-May.

He vividly remembers 7:58 am on March 18 this year.

"I fed Diandian some fresh asparagus shoots and leaves for breakfast as usual, and moments later when I returned, a newborn milu was teetering right beside her," Li said.

"Since it is her third calf and born in the third month of the year, we named it Sansan," he added, referring to the Mandarin word for "three-three".

Li was initially driven by curiosity about the animals, and he has since developed a deep affection for milu and is determined to protect them.

From 2016, he has been on the front line of milu rescue and protection in Yueyang. "As our country is placing more emphasis on environmental and wildlife protection, people are increasingly aware that milu are State-protected animals," Li said.

Milu habitats are usually centered around water, and Li said fishing equipment that once posed a threat to the animals is no longer seen in nature reserves.