Below about 4500 elevation on the interior slope this species was the most numerous rodent, and seemed to reach maximum abundance in the Joshua tree association. About 500 trap-nights in the juniper belt near Graham Canyon yielded 31 specimens, whereas about 300 trap-nights in Joshua tree flats took 34 individuals.
The cheek pouches of many specimens taken in early winter contained green shoots of grass and little dry material. On many occasions rat traps set next to wood rat nests beneath large junipers produced panamintinus, and many of these animals had their cheek pouches crammed full of juniper berries.
In December, 1948, panamintinus was trapped consistently on nights when the temperature dropped to below 20° F. On December 27, 1948, after a three inch snowfall, tracks of this species were noted in the snow at the mouth of Mescal Canyon.
Parts of the skulls of this species were found in many coyote feces from the desert slope.
Specimens examined.—Total, 11, distributed as follows: Los Angeles County: Mescal Wash, 4000 ft., 8 (6 PC); 2 mi. E Valyermo, 4600 ft., 3.
Dipodomys merriami merriami Mearns
Merriam Kangaroo Rat
This kangaroo rat barely enters the area under consideration and is almost restricted to the Joshua tree association, for only a few individuals were taken at the lower edge of the juniper benches. This species inhabits the Joshua tree belt all along the desert base of the San Gabriels.
As mentioned in the description of the Joshua tree association, the relative numbers of Dipodomys merriami and D. panamintinus shifted from 1948 to 1951, possibly concurrent with the seasons of low rainfall in this period. Whereas in 1948 merriami was decidedly less abundant than panamintinus in the Joshua tree belt, in 1951 the numbers were reversed.
In December, 1951, it was found by tending the traps in the early evening that merriami foraged fairly early before the ground had frozen solidly.