HABITAT: The Great Basin Pocket Mouse inhabits arid and semi-arid sandy shrub-steppe covered with 

 short grasses, sagebrush (especially ^A-Zeww/a tridentata), bitterbrush {Purshia tridentata), and rabbit 

 brush {Chrysothamnus), and also is found in pinyon-juniper woodlands. Usually this species is found in 

 habitats with light-textured loose and deep soils where it can burrow, but it also is sometimes present among 

 rocks. The diet includes a variety of grass and forb seeds; this species may be diminished in areas with 

 heavy livestock grazing because of reduced food availability. Loss of sagebrush cover also diminishes 

 abundance. 



COMMENTS : The 1 999 records from the Centennial Sandhills are the first in Montana since 1 96 1 . The 

 status of the Great Basin Pocket Mouse needs further attention and review. Intensive trapping using pitfall 

 arrays could reveal many additional populations and define in finer detail the distribution, status, and habitat 

 associations of the species in the state. 



REFERENCES: 



Hoffmann, R. S., P. L. Wright and F. E. Newby. 1969. Distribution of some mammals inMontana. I. 

 Mairmials other than bats. Journal of Mammalogy 50:579-604. 



Verts, B. J. and G. L. Kirkland, Jr. 1 988. Perognathus parvus. Mammalian Species No. 318:1-8. 



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