撰写Xinhua News Agency, Chengdu, April 14th, New Media Specialist (Reporter Yu Li) On the morning of the 14th, the reporter came to Ya ‘an Base of China Giant Panda Conservation and Research Center, which has the largest captive giant panda population in the world. Susan, a female giant panda, successfully mated with Yangyang, a male giant panda. The center has successfully completed more than half of the breeding and breeding tasks of captive giant pandas this year. Spring is the peak of giant panda breeding, so how do giant pandas choose their spouses?
According to Zhang Guiquan, director of the center’s Ya ‘an base, the artificial breeding of captive giant pandas in China is included in the unified planning, and the optimal pairing is carried out according to the principle of prenatal and postnatal care to ensure the genetic diversity of the population to the greatest extent. The center has 26 female cats participating in the breeding program this year, and 15 have been completed so far.
"According to the observation, Susan’s estrus behavior is typical, and the secretion of estrogen has reached its peak. Now is the best time to mate." Zhang Guiquan said that after discussion, experts decided to put the male giant panda Yibao and Susan together. Yibao is 10 years old this year, which is in the prime of life for giant pandas, and is also considered as "the same age" as Susan, who is 5 years old this year.
In order to promote the mating of female pandas and male pandas, the staff will lock them together after they enter estrus, but they need to be separated by protective fences to prevent them from fighting if they don’t like each other. At this time, female pandas have priority in mate selection. "We will put two or three male pandas around a female panda and let it choose what it likes." The breeder zhangxin said.
What is a giant panda in love like? According to zhangxin, the giant panda will release some signals: leaving odor marks, rubbing the shade, lifting its tail and masturbating. Pandas will also use their own unique "love language": male pandas will bleat, which is to woo their sweetheart with "sweet words". Captured, the female panda who falls in love will make a similar birdsong like "chirp" and "chirp" and respond shyly. If two opposite-sex pandas don’t like each other, they will turn a blind eye to each other, grumble and even attack each other.
It is reported that pandas who like each other naturally mate twice as often as those who don’t like each other after pairing. In contrast, only about one-third of the pandas who don’t like each other mate, and more often, nothing happens. Studies show that pandas in two of a kind are also more fertile: on average, they can give birth to 1.4 baby pandas, while pandas who are barely together can only give birth to one baby on average.
On the morning of 14th, experts waited patiently for a period of time, but Susan and Ipoh, the giant pandas, didn’t "call". They turned a blind eye to each other in the same enclosure and made whining noises from time to time. "Susan doesn’t seem to like Ipoh. They don’t like each other. Try another giant panda, Yangyang." Zhang Guiquan decided to use the alternative giant panda.
Yangyang, a giant panda, was born in 1999 and is 17 years old, which is close to the aging of the giant panda. "The male giant panda with natural mating ability is a national treasure. Under the current captive conditions, the number of male giant pandas with natural mating ability is very rare, accounting for less than 5% of the population, so the range that female giant pandas can choose is not much." Zhang Guiquan said.
It is understood that female giant pandas are not willing to accept by any opposite sex, and they have the ability to conceive for only a few days in a year. Experts often only have 36 hours to find a mate for pandas and let them "make bears". Otherwise, once this period is over, even if the female panda completes natural mating, it will not be pregnant. If the mating of giant pandas is unsuccessful at this stage, experts usually adopt artificial insemination to help giant pandas get pregnant.
In order to make Susan interested in Yangyang, the breeder first played Yangyang’s cry to her with her mobile phone. After Susan was put into the pen, the staff used a bamboo pole to touch Susan’s tail, making it lift its tail and have a desire to mate. After a short period of familiarity and adaptation, Susan, a giant panda, and Yangyang, a giant panda in the same pen, finally hit it off and successfully mated naturally. Experts said that this mating was very successful and the probability of pregnancy was high. About two months later, we will know whether Susan has successfully conceived.
According to Luo Bo, director of the Center’s dynamic management department, there are three major problems in the development of captive giant panda population: difficulty in estrus, difficulty in mating and conception, and difficulty in survival of young. Giant pandas are in estrus every spring. As the temperature rises, their hormone level, estrus behavior and mating desire will decrease from May, which will affect the mating quality. Therefore, March and April are the prime time for giant pandas to breed. In order to ensure that female cats are pregnant, some will also receive artificial insemination as appropriate after natural mating.
By the end of 2015, the number of giant pandas in captivity in the center had reached 218. In recent years, the artificial breeding of giant pandas has been carried out at Bifengxia base in Ya ‘an. Experts say that giant pandas need to mate with each other to successfully give birth to the next generation. If there is no "electricity" between pandas, mating may fail even during estrus. In addition, even if natural mating is successful, it is very difficult for female giant pandas to finally give birth to panda babies — — Their eggs can only survive for 36 to 40 hours, which makes it more difficult for sperm to enter. Even with breeding, only 30% to 40% of female giant pandas can conceive successfully, while the survival rate of their cubs is less than 40%.