Arizona \ 
Exp. Sta. / 
LIFE HISTORY OF THE KANGAROO RAT. 
13 
The ordinary activities of the kangaroo rat in southern Arizona 
can scarcely be said to show any true seasonal variation. The ani- 
mals are active all the year in this region, there being neither hiber- 
nation nor estivation, both perhaps being rendered unnecessary by 
the storage habit, to be discussed in full later (pp. 15-16). and by the 
mildness of the winter climate. On any particular night that the 
weather is rainy, or the ground too wet and cold, activity is confined 
to the interior of the burrow system, and for this reason one has no 
opportunity to see a perfect imprint of the foot in freshly wet soil or 
in snow. On two or three of the comparatively rare occasions on 
which there was a light fall of snow on the Range Reserve a search was 
made for tracks in the snow. At these times, however, as on rainy 
nights, the only signs of activity were the pushing or throwing out 
of fresh earth and food refuse from within the burrow. This is so 
common a sight as to be complete evidence that the animals are 
active within their dens during stormy weather but do not venture 
outside. Trapping has again and again proved to be useless on rainy 
nights, unless the rain is scant and a part of the night favorable, in 
which case occasional individuals are taken. These statements apply 
to the Range Reserve particularly : the facts may be quite different 
where the animals experience more winter, as at Albuquerque, 
X. Mex., although in November, 1921, Vorhies noted no indications 
of lessened activity in that region. 
PUGNACITY AND SOCIABILITY. 
So far as their reactions toward man are concerned, kangaroo 
rats are gentle and make confiding and interesting pets; this is 
especially the case with merriami. This characteristic is the more 
surprising in view of the fact that they will fight each other so 
readily and so viciously, and yet probably it is explained in part by 
their method of fighting. They do not appear to use their teeth 
toward each other, but fight by leaping in the air and striking with 
the powerful hind feet, reminding one most forcibly of a pair of 
game cocks, facing each other and guarding in the same manner. 
Sometimes they carry on a sparring match with their fore feet. 
Biting, if done at all, is only a secondary means of combat. When 
taken in hand, even for the first time, they will use their teeth only 
in the event that they are wounded. The jaws are not powerful, and 
though the animals may lay hold of a bare finger, with the apparent 
intention of biting, usually they do not succeed in drawing blood. 
As Bailey sa} 7 s (1905, 118). they are gentle and timid, and, like rab- 
bits, depend upon flight and their burrows for protection. 
The well-traveled trails elsewhere described (p. 10) indicate a de- 
gree of sociability difficult to explain in connection with their pug- 
