Estimating Birth Dates

Predicting the date of birth is important for the rearing and management of parents and children in the early stages of birth.
Based on past cases, the Park estimates the birth date by focusing on
three indicators.

The gestation period of giant pandas is generally 3 to 5 months. In the case of our park, the shortest gestation period was 93 days and the longest was 163 days, a range of more than 2 months, and it is also recognized that there is a large variation among individuals. This variation in gestation period is due to the panda's unique reproductive mechanism called delayed implantation*.

*Delayed implantation: A form of implantation observed in some mammals. After fertilization, the embryo floats in the uterus, and after certain conditions are met, implantation and placenta formation occur. This is observed in bears, including pandas, and marsupials.

  • Individual gestation period

    Mother : Ume Ume Mother : Rahama
    year of birth gestation period year of birth gestation period
    2000年 103日 2008年 138日
    2001年 93日 2010年
    136日
    2003年 109日 2012年 129日
    2005年 139日 2014年 136日
    2006年 117日 2016年 136日
        2018年 128日
        2020年 163日
    Average 112日 Average 134日
    Shortest 93日 Shortest 128日
    Longest 139日 Longest 163日
  • 出産推定表

    母親 year of birth Date of onset to delivery (days)
    糞量減少(5kg以下) Peak urinary pregnanediol Continuous increase in sleep duration
    Meimei 2000年 24 20 26
    2001年 21
    23 14
    2003年 21 22 24
    2005年 25 21 25
    2006年 22 22 23
    Average ± Standard Deviation 22.6±1.8 21.6±1.1 22.4±4.8
    good beach 2008年 21 20 31
    2010年 23 25 31
    2012年 23 27 31
    2014年 27 20 29
    2016年 22 21 27
    2018年 22 23 27
    2020年 21 17 23
    Average ± Standard Deviation 22.7±2.1 21.9±3.4 28.4±3.0
    Meimei・Rauhin Average ± Standard Deviation 22.7±1.9 21.8±2.6 25.9±4.8

Since 2010, the survival rate of baby pandas in captivity has dramatically increased to 88%. This can be attributed to the establishment of husbandry management techniques for parents and children within the first week of life, a period when mortality rates are high. Predicting the date of birth is also important for the rearing and management of parents and children in the early stages of birth. The Park estimates the date of birth by focusing on three indicators based on past cases.

  • ① A big drop in poop amount (5kg)
  • ② 尿中プレグナンジオール(PDG)のピーク
  • ③ Continuous increase in sleep time

These signs show up in a specific order: first, the mother sleeps more, then her poop amount drops, and finally, there's a peak in urinary pregnanediol. We found that the drop in poop amount was the most reliable sign for predicting birth. Here at the park, we use these three signs to estimate the birth date. Ultimately, we know birth is super close when the female gets restless, her vulva swells, and she starts licking it. Being able to predict the birth date helps us prepare a comfortable environment for the mom and get everything ready to welcome and raise the new baby!

Changes in sleep and feeding times (Yuihin's birth in 2020)

Changes in fecal volume and urinary pregnanediol (Yuihin's birth in 2020)