Zapus hudsonius preblei

A mouse with yellowish brown upperparts; a broad dark dorsal stripe; a white venter and yellow sides; a long, round, sparsely haired, bicolored tail that is longer than the head and body; and very long hind feet; young have softer, paler pelage; upper incisors are grooved on the anterior surface; total length, 187-255 mm; tail length, 108-155 mm; hindfoot length, 28-35 mm (Fitzgerald et al. 1994).

Differs from subspecies Z. h. campestris of northeastern Wyoming and adjacent areas in having a paler, duller dorsum that is less heavily washed with black, and a generally smaller skull with narrower incisive foramina (see Krutzsch 1954:452). Western jumping mouse (Z. princeps) has a more distinct dorsal stripe, a less distinctly bicolored tail, and larger body size. See Conner and Shenk (2003) for information on the use of cranial measurements to distinguish this subspecies from Zapus princeps princeps (presence or absence of the anterior median toothfold of M3 is not by itself a reliable method for distinguishing between the subspecies).

Riparian habitat within about 350 m of streams at elevations between 4,600 - 8,000 feet (Schorr 2012, Trainor et al. 2012, Thompson et al. 2012). One study found irrigation ditches to be utilized (Meaney et al. 2003). High plant species diversity has been associated with capture locations (Ryon 1996, Clippinger 2002). A 14-year study using 499 individuals found that ground cover for forbs was approximately 35% of ground cover, grass approximately 30%, and vertical cover from shrubs approximately 20% (Schorr and Mihlbachler 2018). The same study found survival increased with grass and shrub cover. Survival and home range decline with precipitation (Trainor et al. 2012, Schorr and Mihlbachler 2018). Invasive plants were not strongly avoided in one study (Beauvais and Griscom 2009).

Day nests are raised mats of grasses, forbs, sedges, and rushes placed near shrubs (Bain and Shenk 2002). Maternal nests and hibernation chambers are shallow underground burrows, sometimes lined by leaf litter, or placed underneath logs (Bain and Shenk 2002). Hibernation chambers tend to be farther from streams than maternal nests and closer to shrubs (Schorr 2001, Bain and Shenk 2002).

Annual survival rates generally average below 10% (Meaney et al. 2003, Schorr 2012, Schorr and Mihlbachler 2018). Summer survival rates are drastically lower than winter survival rates (Schorr 2001, Meaney et al. 2003). Capture rates and survival are lower with increasing density of deer mice (Peromyscus maniculatus), suggesting direct competition for resources (Schorr 2012). A 7-year study found survival increased with increasing vole captures, but a 14-year study of the same site found survival decreased with vole captures (Schorr 2012, Schorr and Mihlbachler 2018). May be particularly susceptible to native generalist predators and non-native domestic predators (Clippinger 2002, Smith et al. 2004, USFWS 2007).

The following is based on other subspecies and may characterize this subspecies as well. Nests are often near streams (Smith et al. 2004). Gestation lasts 17-20 days. There are 2-3 litters per year with first litters around July and second litters in August (Quimby 1951, Krutzsch 1954, Whitaker 1972, Smith et al. 2004). Litter size ranges from 2-9 (average 4-6) (Quimby 1951, Krutzsch 1954, Whitaker 1972).