This rat is common in the Joshua tree and juniper belts, and locally
penetrates the pinyon belt at about 5000 feet elevation. It occurs
regularly along the entire desert slope of the San Gabriel Mountains.
The upper limit of the range of this species roughly coincides with the
upper limit of the juniper belt, and within this range it was found to
inhabit areas having widely different soil types. It occurred on the
sandy ground of desert washes, the gravelly soil of the juniper-clad
benches, and the mixed sandy and rocky ground of washes in canyons. A
preference is shown by _panamintinus_ for fairly level ground. Rough
terrain or steep slopes are generally avoided, whereas rather large
colonies of these kangaroo rats are found in small flats of the desert
foothills.
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 deg. 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