Animal Life
Deer
Other animals
Dyrehaven is packed with old hollow trees, and therefore there are many hole-brooding birds; primarily tawny owls, black woodpeckers and the more common spotted woodpecker. The tree creeper also thrives in old trees, and at Mølleåen you can see ravens, nightingales, kingfishers and dippers.
Bats, and not least the noctule bat, hibernate in the hollow trees.
In the middle of the Eremitagesletten is the Iglehullet waterhole and this, as well as other waterholes, have medicinal leeches. This species has been used in medicine for thousands of years, primarily for blood-letting. The medicinal leech can be up to 15 cm long. Other old species in the waterholes include fairy shrimp and horseshoe crabs.
Plant life
Trees
Dyrehaven is well-known for its ancient isolated oak trees and hawthorn (for more information see Attractions), but the park also has nearly all Danish tree species, for instance in Fortunens Indelukke. Trees that die are left to rot. Therefore there are many insects that attract birds.
Mushrooms
Dyrehaven has the greatest biodiversity of mushrooms in Denmark, with more than 300 different species. There is no point in looking for them on the ground, because the deer also like mushrooms. Instead, look for them up in the trees above the reach of the game. For instance, beefsteak fungus which grows on oak trees that it slowly destroys. The beefsteak fungus looks like a real ox tongue. It has a mild acidic taste and is delicious raw and drizzled with lemon juice.