Lake Utonai

Lake Utonai (Utonai-ko) is a freshwater wetland near Tomakomai in Hokkaido Prefecture, Japan, recognized for its importance to waterbirds. It is a relatively small lake set within a wetland and low-lying floodplain.

The wetland is valued for birdwatching, with many species of migratory and resident waterfowl using the area, making spring and autumn notable seasons for visitors. Boardwalks and observation points provide opportunities for wildlife observation while limiting disturbance to habitats.

The lake and its surrounding wetlands have been managed for conservation to protect habitat for birds and other wetland species, with measures to balance public access and ecological protection. Management reflects decades of local conservation effort rather than industrial or agricultural development.

Lake Utonai lies near the coastal plain of southern Hokkaido, close to the city of Tomakomai, within a landscape of low hills, wetlands, and agricultural land.

• Birdwatching season: Important habitat for migratory and breeding waterfowl, making spring and autumn peak times for birdwatching.
• Conservation and access: Managed conservation areas and trails provide controlled public access to protect sensitive wetlands while allowing observation.