There is a lot of dead wood, and that means many insects, so many birds, small and large, including the green and black woodpecker thrive.
Cranes, whooper swans, Eurasian curlews and wood sandpipers are characteristic birds along with somewhat more unusual species such as the jack snipe and the whimbrel. Black grouse and capercaillie also do well here. There are resident golden eagles, and white-tailed eagles appear regularly year-round. Ospreys hunt at Lake Kävsjön. Especially during winter, there are lots of eagles in the National Park as they are given carcasses at a feeding station from November until March.
You can come across moose, roe deer, fox and badger here and there. Otter are also found in the area. About 25 different species of dragonflies flit around during the summer.
There is a plentiful supply of fish in Lake Kävsjön and Kalvasjön, but the small pools in the bog are devoid of fish because of the acid waters.