Order Soricomorpha Author Wilson, Don E. Author Reeder, DeeAnn text 2005 The Johns Hopkins University Press Baltimore Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 1 220 311 book chapter 0-8018-8221-4 10.5281/zenodo.7316519 Sorex (Otisorex) haydeni Baird 1857 Sorex (Otisorex) haydeni Baird 1857 , Mammalia , in: Repts. U. S. Expl. Surv., Vol. 8, 1: 29 . Type Locality: USA , "Fort Union, Nebraska " (later Fort Buford, now Mondak, Montana , near Buford, Williams Co., North Dakota ). Vernacular Names: Prairie Shrew . Distribution: SE Alberta , S Saskatchewan , SW Manitoba ( Canada ); NW Montana southeast to Kansas , east to W and S Minnesota ( USA ). Conservation: IUCN – Lower Risk (lc). Discussion: Subgenus Otisorex ; S. cinereus group ( Demboski and Cook, 2003 ). Karyotype has 2n = 64, FN = 66. Formerly included in but now separated from cinereus by van Zyll de Jong (1980) and Junge and Hoffmann (1981) ; both species are closely related ( George, 1988 ). S. haydeni occurs in grassy habitats while S. cinereus prefers forest and woodland ( van Zyll de Jong, 1980 ). In Minnesota , Stewart and Baker (1994 , 1997 ) and Brunet et al. (2002) found evidence of introgression between haydeni and cinereus .