The breeders have also been monitoring their appetites, body temperatures and feces to ensure their health.

At the Siberian Tiger Park in Harbin, six breeders who are responsible for feeding tiger cubs have also become extremely busy, especially after the first Siberian tiger twins of this year were born on Feb 15.

"Every year during birthing season, the breeders take turns working 24-hour shifts to monitor the pregnant tigers, which are moved to separate living quarters in a special area about a month before they give birth," said Li Dapeng, deputy director of the Harbin park's department of breeding and veterinary medicine. "They also pay great attention to the tiger moms, checking their health by monitoring their appetites and daily activities during the 105-to-110-day pregnancy period.

"Every day, the breeders carefully disinfected both the indoor and outdoor living areas," Li said. "In addition, they prepare an ample supply of nutritious food — including milk and eggs, as well as several kinds of vitamin pills — to help the animals maintain their strength."

This year, five tigers gave birth to 13 cubs, including twins and triplets.

"There are now four pregnant tigers awaiting delivery," Li said. "We are expecting the birth of more than 20 tiger cubs this year."

zhouhuiying@chinadaily.com.cn