Tama Zoo has been continuously working on artificial insemination of Chimpanzee since 2016 to maintain genetic diversity. We are pleased to announce that a pregnancy has now been confirmed through artificial insemination.

Chimpanzee "Decky"	Chimpanzee "Mikan"

Chimpanzee that underwent artificial insemination
(1) Male individuals (sperm donors)
Name: Decky
Visual Male
Age: Estimated 44 years old; estimated birth year: 1978 (place of birth unknown)
In 1980, she arrived at Nagasakibana Parking Garden at an estimated age of 2.
Arrived at Tama Zoo on October 21, 2004.

(2) Female individuals (pregnant individuals)
Name: Mikan
Sex: Female
Age 16, born December 28, 2005 Tama Zoo
No history of pregnancy

The process of artificial insemination and how it led to pregnancy
Because Decky is an individual that cannot mate naturally, he has not produced any offspring at our zoo until now. With the aim of maintaining the genetic diversity of Chimpanzee in Japan, our zoo has been continuously using Decky as a sperm donor for artificial insemination since 2016.
On October 20, 2021, artificial insemination was performed on "Mikan" under anesthesia using semen collected from Decky during training. On November 10, 2021, a human pregnancy test showed a positive result for the first time, and subsequent testing confirmed pregnancy.
Please note that, considering the potential impact on animals, we do not perform examinations such as ultrasound imaging (echography).

Due date
Since the gestation period is reported to be between 227 and 239 days, if we consider the day of artificial insemination as day 0, the birth is expected to occur between the end of May and mid-June 2022.

*Regarding breeding
Female Chimpanzee reach sexual maturity between 10 and 13 years of age. In the wild, the average age of first birth is around 13 years. The estrous cycle averages 36 days. They typically give birth to one offspring at a time, occasionally twins. Offspring are born weighing around 2 kg, and weaning occurs between 4 and 5 years of age. The average interval between births for adult chimpanzees is 4.6 to 7.2 years.

Current status of animal care at our zoo (as of February 24, 2022)
19 individuals (6 males, 13 females)

Domestic breeding situation (as of December 31, 2020)
Breeding situation in Japan: 48 zoos, 303 animals (131 males, 172 females)
Source: 2020 Chimpanzee National Pedigree Registry [Japanese Association of Zoos and Aquariums]

(February 24, 2022)