The IUCN SSC Small Mammal Specialist Group is responsible for three orders of small mammal – the rodents, tree shrews and the eulipotyphlans, made up of the shrews, moles, hedgehogs and solenodons. These three orders contain more than 2800 species, of which 437 are considered threatened with extinction by the International Union for the Conservation of Nature.
The diversity of this group really sets them apart, with an astounding range of adaptations and life histories, from the fishing mice of South America and the river-dwelling desmans of the Pyrenees and southern Russia, to the venom-injecting solenodons of the Caribbean. But the small mammals are generally very poorly studied – many hundreds of species have never been photographed in the wild and even their basic ecology is unknown. Much of the diversity of the small mammals is undiscovered, including many new species yet to be described in regions such as the Congo basin, Indonesia, Philippines and Papua New Guinea.