Deer, boar habitats to spread across most of Japan by 2050: study

The team, including researchers from Tokyo University of Agriculture and Technology and the Forestry and Forest Products Research Institute, is calling for measures to address the animals' expanding habitats.

In the study, published in the British journal Scientific Reports in February, the team projected deer and boar habitats for 2050 and 2100, based on habitat data from 1978, 2003 and 2014, as well as simulations of migration, weather, land use and other factors.

It found that deer and boar habitats could extend to the northeastern prefectures of Aomori and Akita, where their populations are currently believed to be small.

The animals' migratory ability was the largest factor in the projection.

According to the Environment Ministry, the estimated population of deer, excluding those in the northernmost prefecture of Hokkaido, was about 2.46 million at the end of fiscal 2022, and that of boars was about 780,000.

The figures had jumped about 2.7-fold and 1.9-fold, respectively, over the four decades through fiscal 2018.

In March, a series of deer sightings were reported in urban areas in the western prefecture of Osaka, possibly involving deer migrating from neighboring Nara Prefecture. One deer was captured in a residential district in the city of Osaka.

"Deer sightings are also increasing along rivers and in other areas in the Kanto Plain," including Tokyo, said Takahiro Morosawa, a lecturer at the university.

"Their habitats may extend to urban areas unless sufficient countermeasures are taken."