It is known to all that giant pandas are usually in heat during spring and deliver babies in summer or fall. However, there are some pandas who just don’t follow the rules. Let’s go to see who they are.

Xiong Bang，born on Dec 17, 2001 at the Adventure World Park Zoo in western Japan's Wakayama prefecture，was the first baby of panda Mei Mei and Yong Ming, and also the first offspring born in winter in the world. After about two and a half years, Xiong Bang returned to the Giant Panda Breeding and research Center in Chengdu on Jun 21, 2004, and immediately joined the giant panda breeding plan as he entered adulthood. Up to now, Xiong Bang has been a father of several children, such as Da Mao, Xiao Qiao, MaoZhu, and Mao Sun.

Xiong Bang

Xiong Bang

Xiong Bang is not the only panda born in winter. Ai Bang and Ming Bang, Xiong Bang’s little twin brother and sister, were born at the Adventure World Park Zoo in western Japan's Wakayama prefecture on Dec 23, 2006. They were the last babies born by Mei Mei and Yong Ming. The twins spent their whole childhood and adolescence in Japan, and headed back to the Chengdu Panda Base on Dec 14, 2012. This year, Ai Bang has moved to Louguantai Wild Animal Protection and Breeding Center, and has given birth to male twins on Jun 12, 2017，while Ming Bang has lived in Liuzhou Zoo in Guangxi province.

Ai Bang

Ming Bang(Picture from Internet)

Apart from pandas born in winter, there are some pandas born in spring. On 24th April this year, panda Zhi Zhi delivered male twins, Zhi Shi and Zhi Ma, which are the first captive twins born in Chengdu panda base and also in the world this year. The newborn twins weigh 110.7 and 104.9 grams. Now, the twins are nearly 7 months old and totally different from the past.

A Few-Days-Old Twins

Six-Month-Old Zhi Shi

Six-Month-Old Zhi Ma

There may be a doubt about why some pandas were born in spring and winter when most of them were born between summer and fall. It is believed by some panda experts in China that estrus cycle of giant pandas changes along with the environmental change. Maybe some other factors influence the estrus cycle, but all of these hypotheses needs to be underpined by more researches.