An area of the U. S. Range Reserve in the autumn of 1918, showing the
result of failure of summer rains. Such a condition is critical not only
for the stockmen but also for kangaroo rats and other desert rodents,
and results in competition between them as to which shall benefit by
what the range has to offer.]


[Illustration: PLATE III. FIG. 1.--KANGAROO RAT MOUND (DIPODOMYS S.
SPECTABILIS).

Typical _Dipodomys s. spectabilis_ mound on the Range Reserve, under
shelter of desert hackberry (_Celtis pallida_). Most dens on the reserve
are located in the shelter of brush plants, the more important being
mesquite (_Prosopis velutina_), cat's-claw (_Acacia_ spp.), and the
desert hackberry. (See also Pl. VIII Fig. 2.)]

[Illustration: PLATE III. FIG. 2.--KANGAROO RAT MOUND (DIPODOMYS DESERTI).

Den of _Dipodomys deserti deserti_, showing typical wide, low mound with
numerous entrance holes. This species excavates its den in soft, sandy
soil. The tree is a species of _Dalea_.]




DESCRIPTION.


GENERAL CHARACTERS.