WINTER WAYS OF ANIMALS 169 
One day late in February I visited the yard. 
The elk plainly had lost weight but were not in 
bad condition. While I lingered near the entire 
herd joined merrily in chase and tag, often 
racing then wheeling to rear high and fence with 
heads. If I counted correctly this herd went 
through the entire winter without the loss of an 
elk. 
But the caribou appears to be the only animal 
which migrates between summer and winter 
ranges, that is, which makes a long journey of 
hundreds of miles; as much change of place as 
made by many species of migrating birds. The 
main cause for this migration is the food supply, 
but myriads of mosquitoes in the woods may be 
one cause of the moose moving each summer far 
into the north where there are grassy prairies 
and large openings in the woods. But for 
winter they seek food and shelter in a yard in 
the forest. 
While snowshoeing in the forested mountains 
to the southeast of Long’s Peak I came upon 
a mountain lion track startlingly fresh. I fol- 
lowed it to a den beneath a rock pile at the bot- 
tom of a cliff. Evidently the lion was in. 
Seeing older tracks which he had made on leaving 
the den, I trailed these. After zigzagging 
through the woods he had set off in a bee-line 
for the top of a cliff. From this point he evi- 
