126 



NORTH AMERICAN, FAUNA 66 



Family ZAPODIDAE (jumping mice) 



MEADOW JUMPING MOUSE 

 Zapus hudsonius americanus (Barton) 



Dipus americanus Barton, Trans. Amer. Philos. Soc, 4: 115, 1799. 



Type locality. — Schuylkill River, a few miles from Philadelphia, Pa. 



General distribution. — Southeastern United States, east of central Indiana, 

 and south of central New York, southward into northern Georgia. 



Distribution in Maryland. — Occurs in all sections of the State. 



Distinguishing characteristics. — Teeth 1/1, 0/0, 1/0, 3/3, = 18; upper 

 incisors grooved; tail very long, blackish above, white below (not 

 white tipped); hind legs greatly elongated; pelage short and coarse; 

 coloration yellowish orange, suffused with blackish, the blackish 

 particularly concentrated in the middorsal area and generally forming 

 a rather broad band from nose to tail; coloration of underparts white, 

 sometimes suffused with yellowish orange. 



This mouse is readily distinguished from all other Maryland mice, 

 except the woodland jumping mouse {Napaeozapu^ insignis)^ by its 

 very long tail and powerful elongated hind legs. It is distinguishable 

 from Nafoeozafus by the presence of a premolar in the upper jaw, the 

 absence of a white tail tip, and the more yellowish coloration (as 

 opposed to orange in N apaeozapus) on the flanks. 



Measurements. — Measurements of three adults from the vicinity of 

 Seneca, Montgomery County, are as follows: Total length 195, 194, 

 194; tail 120, 110, 110; hind foot 26, 28, 28; ear 11, 10, 10; greatest 

 length of skull 21.6, 22.0, 22.7; zygomatic breadth 10.5, 10.9, 10.6; in- 

 terorbital breadth 4.2, 3.9, 4.0 ; length of maxillary toothrow 3.6, 3.7, 

 3.5. 



Habitat am.d habits. — ^Krutzsch (1954, pp. 349-472) revised this 

 genus, and gathered together its natural history data. Most of the 

 following is based on his account. 



The meadow jumping mouse inhabits thick vegetation, usually 

 grasses or f orbs, or both, in areas near running water. It is found both 

 in woodland and farmland, but is most abundant in open moist areas. 

 In Maryland, the species occurs throughout the State in suitable 

 habitat, although nowhere does it seem particularly abundant, except 

 perhaps on Assateague Island, where it is common in the mixed cord- 

 grass and myrtle back of the ocean dunes. 



The species is cyclical in abundance, being more numerous in some 

 years than in others. It is ordinarily a nocturnal animal, appearing 

 in the early dusk and remaining active until predawn. Occasionally, 

 individuals will be active during daylight hours. Meadow jumping 

 mice hibernate in the winter. It appears that it is necessary for this 



