The Natural History collection was one of the major founding collections of the museum, as the museum’s first curator Arthur Smith was also the Honorary Secretary of the Lincolnshire Naturalists Union (LNU), and a keen natural historian. Many LNU members have since donated their comprehensive personal collections to the museum.
The collection forms an important reference group of Lincolnshire flora and fauna, including birds and bird eggs, mammals, coleoptera (beetles), lepidoptera (butterflies), diptera (flies), hymenoptera (bees, wasps etc), heteroptera (bugs), crustacea (sea creatures), molluscs and herbaria.
A number of collections, for example the J E Mason collection of heteroptera, the W Wallace collection of diptera and the G W Mason collection of lepidoptera are important as the only known Victorian collections of their type in the County.
The collection also includes the museum’s pleistocene fauna (animals that lived during the Ice Ages). These include evidence of woolly mammoth, straight tusked elephant, deer, elk, horse and bison.