The bird sanctuary at Rungstedlund encompasses only 15 hectares but hosts a bountiful bird life. 35 different species breed here, and many others visit the area to seek food. Thanks to, among other things, the old trees and over 100 nesting boxes, there is a teeming population of hole-nesting birds here. In certain years, there are around 10 pairs per hectare. The great tit is most numerous, with the blue tit number two. In addition, from time to time, a redstart or a pied flycatcher can be seen. Jackdaws are permanent residents; night owls are heard regularly and stock doves more rarely. Fieldfares and hawfinches are heard from the treetops, while nuthatches, treecreepers and large spotted woodpeckers are seen on the trunks, as robins and wrens bustle about among piles of mulched leaves and twigs on the forest floor.

Kestrels will mouse over the meadows, where swallows sweep between the grazing animals. Herons, mallards and moorhens are often seen in the lakes, while sparrows and swifts dwell beneath the eaves of the museum.