In previous articles, we introduced the circumstances leading up to the birth of "Dekopon" (female), a baby Greater One-horned Rhinoceros kept at Tama Zoo. This time, we will report on Dekopon's growth from her birth on September 3, 2024, until she turns one year old, in two parts.

On the morning of September 4th, the day after the birth, when we went to Greater One-horned Rhinoceros enclosure, both the mother "Gopon" and her cub "Dekopon" were calm and relaxed.

On this day, we kept Gopon indoors all day as a precaution, but she kept looking out the window, shaking her head, and seemed to want to go outside. We were worried that she might be restless, but she took good care of Dekopon, encouraging her to stand up and even nursing her. This was Gopon's fourth litter, and she seemed very confident in her parenting.


Dekopon oranges growing next to Gopon oranges (photographed on September 4, 2024)
On September 5th, the animal was moved from the indoor exhibition room to the adjacent room (commonly known as the "birthing room," although the birth took place in the indoor exhibition room), and the indoor exhibition room was cleaned for the first time in two days.


A simple floor plan of the rhinoceros enclosure
At this point, Gopon seemed to be bothered by the sound of doors opening and closing, something he hadn't noticed before the birth, and appeared to be on high alert. However, we handled the situation carefully and were able to successfully move him between rooms.


A mother and baby resting in the birthing room (photographed on September 6, 2024)
After about a week, the horn-like protrusions on the Dekopon pup began to gradually become more prominent. We also started to see changes in its behavior, such as rubbing its head against the cedar planks attached to the indoor fence and playing by itself.

Although it had not yet begun to eat solid food, it was observed taking in wood chips laid in the room and root vegetables intended for Gopon. On September 18th, it was confirmed that its upper molars had begun to erupt, and two to three weeks later, it began to take in green grass and soft leaves more frequently.


The corners are starting to bulge slightly (photo taken September 16, 2024)
Also, the bumps on her buttocks have started to become more noticeable.
On October 2nd, when he was about one month old, Dekopon experienced being released into the paddock (an outdoor, non-public area) for the first time. At first, Dekopon followed Gopon cautiously, but after about an hour, he began to lead Gopon, and the first day's practice session ended after about three and a half hours.

From the next day onward, the movement became smoother, and gradually we began to see more active behavior, such as running around the paddock and trying to wake up Gopon when he was sleeping by putting his paw on him.


First time in the paddock (photographed October 2, 2024)
This concludes the first part. In the second part, we will introduce everything from the start of the exhibit in the enclosure to recent events such as weight measurements, so please look forward to it!

[Arashida, Tama Zoo]

>>Click here for Part 2

◎Related articles
・ Aiming to breed Greater One-horned Rhinoceros: A report on the cohabitation situation of "Gopon" after his arrival at the zoo. (November 12, 2021)
・ Greater One-horned Rhinoceros "Gopon" may be pregnant – if she gives birth, it would be the first birth at Tama Zoo in 50 years, since 1973. (June 26, 2024)
・ Greater One-horned Rhinoceros has been born! This is the first birth at Tama Zoo in 50 years! (September 5, 2024)
・ How Greater One-horned Rhinoceros "Dekopon" came to be (Part 1) (July 25, 2025)
・ How Greater One-horned Rhinoceros "Dekopon" came to be (Part 2) (September 3, 2025)

(September 22, 2025)