Taxonomic revision of the Palaearctic rodents (Rodentia). Sciuridae: Xerinae 1 (Eutamias and Spermophilus)
Abstract
We reviewed the Palaearctic Xerinae (Rodentia: Sciuridae) from the genera Eutamias and Spermophilus. On the basis of published data and our own examination of >2500 museum vouchers we recognize 12 species and 19 subspecies: Eutamias sibiricus (with three subspecies: senescens and barberi in addition to the nominotypical one), Spermophilus citellus (incl. gradojevici and karamani), S. taurensis, S. xanthoprymnus (with gelengius), S. suslicus (odessanus is a subspecies), S. alaschanicus, S. dauricus, S. pygmaeus (incl. musicus and planicola), S. fulvus, S. major, S. erythrogenys (with heptneri, brevicauda and pallidicauda), and S. relictus (incl. nilkaensis).
All species group names (109 in total) are reviewed and linked to senior synonyms. Descriptions are provided for valid taxa, together with photographs of skins or living animals, and drawings of skulls.
Geographic ranges are mapped for all species and subspecies. We considered also the Nearctic chipmunk Tamias striatus which is feral in one site in western Germany.
Introgresive hybridization obscures species limits in Spermophilus since it produces paraphyletic or polyphyletic taxa in molecular trees. Hybridization, which is probably facilitated by a general promiscuous multiple paternity in sousliks, is widespread in the genus and has been documented between seven species: S. major × S. fulvus, S. major × S. pygmaeus, S. major × S. suslicus, S. major × S. erythrogenys brevicauda, S. erythrogenys pallidicauda × S. alaschanicus, S. pygmaeus × S. suslicus, and S. citellus × S. suslicus.
Conspecific subspecies are frequently delimited by rivers. Our revision of tribal division of Xerinae resulted in a description of a new tribe Sciurotamiini which includes the genus Sciurotamias.