Why the Number of Thunderbirds Has Decreased--Distance from Nature Wavering in the Name of Conservation - May 2025

Why the Number of Thunderbirds Has Decreased--Distance from Nature Wavering in the Name of Conservation - May 2025
The Japanese grouse lives in the alpine region of Norikura-dake. Norikura. It was once widely seen in the high mountains of central Honshu, but is now an endangered species and subject to protection. In May 2025, the Ministry of the Environment attempted artificial insemination by collecting sperm from five wild individuals, but one bird lost its life in the process. The question behind this incident, however, is not simply failure, but the essential question of why the thunderbird's numbers have declined so much in the first place.

The primary cause is the collapse of their habitat due to climate change. Grouse are survivors of the Ice Age and can only live in cold alpine zones. Global warming has changed the vegetation in the alpine zone, resulting in the loss of a cooler environment and the invasion of natural enemies such as foxes and crows, which were originally found only in the lower regions. As a result, their eggs and chicks were preyed upon, and their survival rate declined significantly.

In addition, anthropogenic disturbance caused by tourism development cannot be ignored. The development of mountain trails, the expansion of ski resorts, and the convenience of mountain transportation have brought hundreds of thousands of people a year into this once tranquil habitat. The proximity of humans is stressful for grouse, negatively affecting their breeding and foraging behavior. In addition, the theft and trampling of alpine plants, which provide food for the grouse, has further reduced their food resources.

The Ministry of the Environment is promoting a three-pronged "protection and propagation project" to curb these effects: capture, propagation, and reintroduction. However, the philosophical question remains: Is it really right to manage nature by human hands? Artificial insemination is another method that has a low reproductive success rate and is far removed from nature's natural behavior patterns.

The decline of the thunderbird is not merely a "wildlife extinction crisis," but a stark warning about how we relate to nature. As a result of human activities that have warmed the mountains, opened them up, and brought them closer together, the life that was supposed to live there is disappearing. How should we accept responsibility for this? The restoration of habitat is a means to an end, and the question is how to build the idea of "living together" beyond that.