Training for Polar Bear "Ikoro" – in preparation for its move to Tennoji Zoo
October 3, 2026
Ueno Zoo welcomed "Ikoro" (male, born in 2008 at Sapporo Maruyama Zoo) in 2015, and since 2016 has made several attempts to house him with "Dea" (female, born in 2008 at Fasano Safari Park in Italy) for the purpose of breeding.
As the years passed, the relationship between the two improved, and mating was observed. However, unfortunately, it did not result in births. Artificial insemination was also attempted, but it was not successful in leading to reproduction.
As previously announced, we will be moving Ikoru to Tennoji Zoo in Osaka City, where a new Polar Bear enclosure has been completed, in order to allow him to breed with a new female polar bear.
Training to get used to the transport cage has begun.
We will be using a transport cage for transportation. Therefore, we are currently working on training Ikoru to get used to the transport cage.
Polar Bear enclosure at Ueno Zoo has a door for moving animals in and out. The transport cage is secured to this door, and Ikoru is guided into the cage and then transported out.
Ultimately, we are systematically planning our training so that we can safely place Ikoru into the transport cage without agitating him, ensure he remains calm, and then safely close the cage door.
Training in a squeeze cage
Training began even before the transport cage arrived. First, they started practicing using a squeeze cage (a cage used for medical treatment) in Polar Bear enclosure. The squeeze cage is just under 2 meters deep and just under 1 meter high and wide, making it smaller than the actual transport cage that will be used.
The cage is too small for Ikoru, who is about 220cm from nose to tail, so we have never put him in it before. When we tried to lure him in by placing food inside the cage, he could only fit his upper body in and was very wary.
We had been doing various training sessions with Ikoro for health management purposes, and he learned them all quickly. So, starting the next day, we continued training him two to three times a day for about 20 minutes each time, and by the ninth day, he was able to calmly put his whole body inside. After that, when we taught him to assume a sitting position, he was able to maintain that position inside.
Practicing closing the squeeze cage door
As the second step, we practiced closing the door of the squeeze cage while Ikoru was inside.
If you suddenly open the door behind him, Ikoru might get excited. So, we started by getting him used to the sounds people make near his cage and door.
At first, even the slightest noise would cause them to quickly run out of their cage, but after a few days they got used to it and are no longer afraid of metallic noises or knocking on the door.
After that, we started practicing closing the door. We gradually increased the amount we closed it each day, starting with a few centimeters, then 10%, then 30%, and eventually he was able to maintain his sitting posture even when the door was closed about 80%.
Arrival of transport cage
From mid-September onwards, the relocation plan was finalized, and the transport cages for the removal arrived.
A week later, one morning, we secured the transport cage to the door of the exit and tried to guide Ikoru inside. He seemed a little confused at first, but he was inside completely within about 10 minutes.
During the second training session, he seemed even calmer and responded to the command to sit in the dog position. The transport cage is quite different in specifications from the squeeze cage, so we expected it would take some time for him to get used to it, but Ikoru seems to have understood that "if I go in here and sit, I will get good treats."
As the next step, we will begin practicing moving the door, just as we did with the squeeze cage, and continue training Ikoru to remain calm inside the transport cage so that we can safely close the door.
The schedule and travel dates for Ikoro are selected as top priorities based on the condition of the trainees during training. Depending on the travel period, transportation using air-conditioned vehicles is also implemented, prioritizing safety.
Looking forward to seeing Ikoro active at Tennoji Zoo's new Polar Bear facility, the Polar Bear Coast, we will continue to devote ourselves fully to health management and transport cage training.
〔Ueno Zoo East Garden Breeding Exhibition Section 〕