166 
JOURNAL OF MAMMALOGY 
So far as I have learned the food of this mouse consists entirely of 
the soft pulp contained in fir and spruce leaves, and the inner bark of 
the tips of twigs of the same trees. The feeding process is interesting. 
The mouse sits hunched up and uses its forefeet as hands. Nipping off 
a twig with the razor-like incisors, he next chooses a leaf, which is 
drawn through the teeth lengthwise; this process splits the leaf in the 
exact center and the fleshy part is left in the mouth. The amount of 
food in each leaf is very small but the animal is a rapid feeder and soon 
disposes of a lot of leaves. The skin of the mouth and throat of two 
specimens collected was stained a rich green color. Most occupied 
nests have a few food twigs on them, this, with the fact that the shredded 
leaves are used as nest material, is very good evidence that most of 
the feeding is done in the nest or on its roof. 
When the mouse is disturbed in the nest it will sometimes run out on 
a limb, down the tree head foremost, or will jump to the ground. The 
two mice occupying the nests at the Adams Ranch, above referred to, 
both jumped to the ground when I prodded the nests with a pole. 
They can run rapidly both in the tree and on the ground. At the 
Lowery Ranch on Rogue River I saw numerous nests in a second 
growth of Douglas firs back of the house. Inducing a small boy to 
climb to a likely looking nest I kept careful watch to see if anything 
left it when he began the ascent. Nothing happened, so I asked him 
to dissect the nest and throw the material to me. No mouse was seen, 
but as the nest had been recently occupied I was not satisfied. After 
careful search I saw the little fellow sitting upright on a dead twig 
about ten feet above my head. He was sitting hunched up in almost a 
round ball with the long tail hanging over to one side. How, and when 
that mouse reached his perch without either of us seeing him will always 
be a mystery to me. Although I am convinced that these mice colo- 
nize to a certain extent I have never heard of two adults occupying the 
same nest. 
The two mice taken at the Adams Ranch were captured alive and 
placed in a box with part of their nesting material and a few fir twigs 
for food. As I was leaving the ranch next morning I put box and mice 
in my pack-sack. The next three days I packed these mice over about 
sixty miles of rough forest trails only to find them in a dying condition 
when I reached the coast. They ate quantities of fir twigs and leaves 
supplied them fresh daily, but as the weather was warm, the continual 
jostling on my back was too much for them. While handling live 
specimens I have never had one attempt to bite. 
