The Ezo Japanese Pika, a famous variety of pika, is a relict from the ice age. It grows to a size of 15 cm, is dark brown in color with rounded ears, and lets out a sharp, alarming cry. Even though the Ezo Japanese Pika lives in central Hokkaido within the alpine zone of the Hidaka mountains, their distribution in Southern Hidaka is universally limited to the southern area. It is also found at very low altitudes, 50 meters above sea level, around the rocky terrain of Mt. Apoi and the Horoman River.
The Himechamadara Seseri (Seseri species) is a butterfly that grows to a length of about 2.5 cm, and is brown in color with small white speckles. This butterfly lives exclusively at Mt. Apoi and exists nowhere else in Japan. The larva eats the Kinrobai alpine flower and matures into an adult during May and June. This one month span is the only time it can be seen. It’s believed that the Himechamadara Seseri was widely distributed during the Ice Age but was left here at Mt. Apoi as the climate warmed.
The Apoi Maimai is an endemic species of snail (recorded as a new species in 1970) that exists around Mt. Apoi and near the Horoman River. Related to the Takahide Maimai of the Hime Maimai genus that exists in Hokkaido, the Apoi Maimai can be found in the crevices around the peridotite rock. The shell of the Apoi Maimai only grows to a size of 1 cm wide, is dark brown in color, and sprouts thin stiff hairs on the surface of the shell.