These wetlands are home to a colony of the scarlet dwarf (Nannophya pygmaea), Japan’s smallest dragonfly. Its body is about 2 cm long, and males turn a bright red color when mature. It is designated as a near-threatened species by Yamagata Prefecture and as a Natural Treasure by Yuza Town, and the local community has established an association dedicated to the protection and preservation of the scarlet dwarf.

The area is rich in vegetation, constantly supplied by underground water, and the wetlands are stable, not freezing even in winter. In addition to the scarlet dwarf, other damselflies and dragonflies fly around the area, including the kiitotonbo damselfly (Ceriagrion melanurum), the emerald damselfly (Lestes sponsa), and the golden-ringed dragonfly (Anotogaster sieboldii). The area also serves as a small sanctuary where the Japanese iris (Iris ensata) and roundleaf sundew (Drosera rotundifolia) bloom, and newts can be found living in the areas with deeper water.

Shirai-shinden Wetlands are normally closed to the public, opening only on weekends in July.