The Canadian Museum of Nature's extensive Bird Collection is comprised of study skins, mounted specimens, skeletons, nests, eggs, and some fluid-preserved specimens. In all, there are approximately 125,000 specimens representing ca. 2,600 species (one quarter of the world's species). This reference collection documents the extensive variation found in bird species across Canada, but also in countries where some of our birds spend the winter, such as Mexico or Brazil. The collection contains specimens taken over a long span of time, including species that are now extinct.