Escape of Common Wolf from Tama Zoo (4th report)

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Updated on February 26, 2026

Regarding the incident on December 28, 2025 (Sunday) in which one Common Wolf wolf escaped from Tama Zoo (hereinafter referred to as "the Park"), we report the results of the investigation into the cause of the incident and the measures to prevent recurrence as follows.

In the future, Tokyo Zoological Park Society will thoroughly reinforce the importance of safety in the daily work of every staff member.

I would like to once again sincerely apologize for the inconvenience and worry I have caused.

1. Overview of the accident

On December 28, 2025 (Sunday) at approximately 10:10 AM, "Sui" (female, 2 years old), Common Wolf, escaped from the small enclosure of the wolf house Asian Zone onto the viewing path.
Because Sui entered the woods within the park, a capture team formed by zookeepers tracked and cornered her, and at around 2:15 PM, a veterinarian from the park's animal hospital administered an anesthetic using a tranquilizer gun behind Watching Center.
After confirming the effects of the anesthesia, the animal was placed in the nursery's vehicle, and its containment was completed.

Our park temporarily closed at 1:20 PM. Visitors were guided to indoor facilities within the park until safety could be confirmed, and were asked to leave once safety was assured.

2. Results of the investigation into the cause of the incident

Tokyo Zoological Park Society 's Crisis Management Committee established an accident investigation committee and estimated the following to be the main causes leading to the escape.

Four days prior to this incident, on Wednesday, December 24, 2025, we noticed that "Kayoran" (male, 10 years old), who was living with Sui in the large enclosure, was limping, so we separated Sui into the adjacent small enclosure.
After separation, Sui appeared restless.

The plants covering the retaining wall of the small enclosure (mainly ivy, etc.) were regularly pruned and well-maintained, but the southern retaining wall from which Sui is presumed to have escaped was covered in ivy that her claws could grip. It is estimated that Sui, being only two years old and light on her feet, used this as a foothold to climb the approximately 3.3-meter-high retaining wall.

The retaining wall of the small enclosure was constructed to a sufficient height and structure according to all standards, so it was not anticipated that the animals would climb the wall and escape.
Therefore, no additional fences (such as anti-climbing devices or electric fences) to prevent escape were installed on top of the southern retaining wall from which the escape is presumed.

3. Measures to prevent recurrence

(1) Measures taken at the wolf enclosure in our zoo

Since it is presumed that the vegetation (mainly ivy, etc.) covering the retaining wall was the ultimate cause of the escape, we will promptly remove the ivy and other vegetation from the retaining wall of the small enclosure to expose a smooth surface and make it difficult to climb, as well as implement the following escape prevention measures.

Pruning and cutting down trees in the enclosure that could serve as footholds for animals, and removing accumulated soil and decorative stones.

To physically prevent animals from escaping from the enclosure, additional fences (such as anti-climbing devices and electric fences) will be installed.

We have added more devices (cameras, recording equipment) to monitor actions that could lead to escape, such as attempts to climb retaining walls or digging holes near the surrounding fence.

After implementing the above measures and undergoing a facility inspection by the Tokyo Metropolitan Animal Welfare Consultation Center, we plan to reopen the enclosure for use.

Furthermore, as a further safety measure, the large enclosure currently in use will also be reinforced with additional electric fences and monitoring equipment, similar to the smaller enclosure.

(2) Strengthening the maintenance and management of animal exhibition facilities

Following this incident, Tokyo Zoological Park Society is conducting emergency inspections of animal exhibits at all metropolitan zoos under its management.
In particular, for outdoor enclosures, we will thoroughly manage the facilities through regular inspections by multiple staff members, not just the assigned animal caretaker, to ensure that plants and structures (such as wooden structures) do not provide animals with footholds.
We will renovate and reinforce the facilities as needed and take measures to minimize the risk of escape due to unexpected behavior of the animals.

(3) Thorough awareness of accident prevention

We will strengthen training and guidance for staff involved in animal care and management regarding the risk of animal escapes, and will also thoroughly reinforce awareness of this in their daily work.

Through these efforts, we will establish a comprehensive system to prevent recurrence, and strive to ensure the safety of visitors and improve animal welfare.

Escape locations and capture sites of Common Wolf

Please see below for the first three reports.

First report 第2報第3報

(February 26, 2026)