The White-Tailed Jack Rabbit 33 
of outside of cars dusky brownish ; border edged with ochraceous 
bufify; posterior half of outside of ear white, with a broad terminal 
black patch extending to include border of ear at tip. 
In winter pelage this species varies greatly, depending upon 
locality, or perhaps it would be more exact to say upon climate. 
Where there is snow on the ground all winter, the animal is practi- 
cally white, the rump being entirely so, while the longest hairs of 
the back are white, but underneath these are dark hairs which show 
when the hair is lifted up; the nape is white, and the pectoral 
band becomes very pale ; the black tip of the ear is always persistent. 
In those localities where the ground is bare all or nearly all winter, 
the upper parts become paler than in summer, the color varying 
from a quite clear gray to a pale pinkish buff, and this variation 
is not confined to any particular locality, for the two colors may 
be found in specimens from the same place; the rump is almost 
always white; the buff on the legs is also paler than in summer. 
The upper outline of the skull is quite highly arched, and the 
rostrum is short, broad, and deep. The posterior process of the 
supraorbital is wide, flaring outward and upward, and not ap- 
proaching closely to the frontal, nor attached to it by a cartilage. 
Distribution. — This species is found east of the Rocky Mountains, 
south from the plains of the Saskatchewan in Alberta, Saskatche- 
wan, and Manitoba, through Montana, most of Wyoming, the 
Dakotas, Minnesota, Iowa east to the Mississippi, Nebraska, north 
half of Kansas, and in Colorado. 
In Colorado, east of the foothills, it is found south nearly to the 
Arkansas River; west of the foothills, and east of the Continental 
Divide, it occurs south to the New Mexico line, and is found along 
the middle-northern border of New Mexico. East of the moun- 
tains the White-tailed Jack Rabbit is relatively more abundant than 
the Black-tailed in the northern half of the region, while the reverse 
is the case for the southern portion. 
Habits. — All the Jack Rabbits have from two to six young 
in a litter, four being probably the average number, but 
whether more than one litter is born in a season I cannot say, 
at least for our Colorado species. But the young are prob- 
ably born in May or June, and possibly in late April, this 
depending no doubt somewhat on locality. The young of 
all these rabbits are born fully furred and with their eyes 
opened. 
All the species of Jack Rabbits are lovers of the open 
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