Store Mosse has a rich fauna. In the centre of the national park lies the lake Kävsjön, a well-known and protected bird lake.

Mammals

All year round the chances are good of seeing the king of the forest, the moose, in the national park. Roe deer, foxes and badgers also move around the area. On occasion, lynxes also pass through the national park. Småland's national animal, the otter, can be found in the area.

In the national park, you can also encounter six of Sweden's 19 bat species. At Södra Svänö you have the greatest chance of seeing bats hunting during summer evenings.

Insects

Dragonflies thrive in Store Mosse's varied natural landscape. Of Sweden's approximately 60 species, nearly half are found in the area.

Birds

The curlew is Store Mosse's main characteristic bird. It is common out in the vast expanses. Slightly less common characteristic birds in the national park are the Eurasian whimbrel and the jack snipe. The jack snipe's song can often be heard at the bird tower in Hagudden in May.

There are a lot of birds by the waters of Kävsjön and its surrounding rockery. In the spring there is a good chance of seeing cranes, whooper swans and mallards and other duck species. The western marsh harrier and the hen harrier often patrol over the rockery. Ospreys like to hunt in the waters of Kävsjön. In winter you can see wrens sitting on the small birches.

There are resident golden eagles in the national park. Both golden eagles and white-tailed eagles appear regularly all year round. There are especially many eagles in winter when the birds of prey feed in the national park from November to March. This can be followed via the webcam that is running every day during the season.

There is a lot of dead wood in the national park's forests, which is home to many insects, which means that different woodpeckers thrive: lesser spotted woodpeckers, great spotted woodpeckers, greenfinches and black woodpeckers.

Outside the entrance to the Store Mosse visitor center, there are several bird feeding tables all year round. It is often full speed and the visitor has a front row seat in the forecourt of the nature reserve. Common birds are tawny owls, blue tits, greenfinches but also slightly more shy visitors such as crested tits, treecreepers and squirrels.

Black grouse can be found in the national park and lek mating can be seen in several places on the bog. There is a hideout for watching lek mating west of Lilla Lövö that is open to visitors. The hideout is located about 50 meters from the hiking trail. At certain times of the year when the bog is extra wet, the hideout is difficult to access.

Fish

There is plenty of fish in Kävsjön and Kalvasjön. But the bog's ponds are empty of fish due to the low pH.

Mollusks

In the chalky Björnekulla bog there is the rare snail Vertigo geyeri, which is barely two millimeters long. Otherwise, the mollusk fauna has not been inventoried.