The bird collection of the Royal Belgian Institute of Natural Sciences is made up of around 82.000 specimens. It includes a significant collection of skeletons and eggs as well as type material for 92 species. It is one of the Institute's oldest collections and for much of the historical material, including the tropical birds, the Institute owes thanks to ornithologist Bernard du Bus de Gisignies, the first director of the Museum of Natural Sciences in 1848. Alphonse Dubois, who was appointed curator of the vertebrate collections in 1869, was the first to describe many of De Gisignies’ specimens. In the 1930s Zoologist René Verheyen added a great deal of material to the ornithological collections and in particular, an exceptionally large collection of Belgian and Central African fauna.

The Royal Belgian Institute of Natural Sciences Bird Collection contains 100061 digitised specimens of 10477 taxa. The following classes are included: Actinopterygii, Amphibia Linnaeus, 1758, Aves, Mammalia Linnaeus, 1758, Reptilia Laurenti, 1768