This species is a closed relative of Western Marsh Harrier occurs in Europe. The range of this harrier is from the Lake Baikal to the eastern tip of Eurasia continent. Although a large number of this harrier winters in Japan, most of them come from the breeding area in Eurasian continent. Only a small number of the harrier breeds in Japan. The number of the breeding pair is estimated only 100. The breeding area is mainly in northern Japan including Hokkaido.

In central Japan, only two areas are known as a regular breeding areas of this harrier; Lake Kahokugata , Ishikawa and Kisozaki Reclaimed Land, Mie. The latter is originally reclaimed for agriculture and is 443 ha. But the land was abandoned without use. The land became grassland, and the harrier began to breed. At maximum three pairs succeeded in breeding.

Joining with two other conservation groups, our society has sent a letter to Mie Prefecture Government in 1993.  In this letter, we proposed that the grassland of the reclaimed land should be remained as a sanctuary for wintering birds of prey and breeding harries. However, Mie Prefecture Government had changed the northern part of the land into athletic park. Moreover, a large number of photovoltaics (PV) modules are set on the southern area in 2014. The remaining area for harrier is greatly reduced. However, one or two pairs of the harrier still make effort for breeding. In 2013 and 2014 one pair succeeded in rising hawklings in this reclaimed land.