The Mule Deer 
23 
Habits. — While this deer has just as good a right to the 
name "Black-tail" as the Californian and Pacific Coast ani- 
mal, yet it seems best to avoid confusion and to call it the 
Mule Deer, a name which has never been applied to the other. 
This species is rather fond of the rough country, the mountains 
and foothills rather than the valleys and river bottoms, though 
it is likely at times to be found on any kind of ground within 
its range. In summer it moves up to considerable elevations, 
the does stopping somewhat lower down than the bucks, more 
among the aspens and other deciduous growth, while the bucks 
often get up into the green spruce and pine timber. There 
is, however, much variation in these habits and he who tries 
to lay down a hard and fast rule for all the deer will surely 
get himself into trouble. In autumn and early winter the 
deer move lower down; in western Colorado, in Rio Blanco 
and Routt counties, this is a regular migration, the animals 
coming from the higher mountainous parts of those counties 
where most of them spend the summer and drifting gradually 
to the lower altitudes where there is little or no snow, gather- 
ing in herds, which twenty-five years ago and less numbered 
thousands of individuals. Even to-day, in the thinly settled 
sections of those counties, the number in these winter 
gatherings is often great. In other parts of western Colo- 
rado this migration also occurs, but is perhaps not quite as 
noticeable, owing to the smaller number of deer. 
This species feeds much on the leaves of various bushes 
and other plants, and perhaps not as much on grass as some 
other deer. 
The breeding habits are much the same as in other species, 
the fawns being born in May or June, and the rut being in the 
fall, late September and October. The bucks chase the 
does continually and sometimes have several in their harems. 
Hornaday says this species nearly always has two young 
at a birth. 
