On the Pacific face of the mountain range this bat was recorded commonly
below approximately 5000 feet elevation, where it seemed to be most
common in the oak woodland of canyons. On the desert slope it was
collected at Jackson Lake in yellow pine woodland, in Mescal Canyon in
the juniper belt, and bats presumably of this species were observed at
several points in the pinyon-juniper woodland.
Individuals of this species were often observed foraging from five to
ten feet above the ground around the alders and _Baccharis_ near San
Antonio Creek, but they did not fly so low or so near the vegetation as
did _Myotis evotis_. Here they were taken from 18 minutes to 55 minutes
after sunset; this indicates an early and short forage period.
This bat may be active even in winter. On February 8, 1952, in lower San
Antonio Canyon, a bat, probably of this species, was noted foraging; and
collecting in early November, 1951, yielded specimens.
On May 22, 1951, a female obtained in San Antonio Canyon had one
five-millimeter embryo, and subsequently all the females examined had
embryos until June 12, when collecting was discontinued.
_Specimens examined._--Total, 16, distributed as follows: Los
Angeles County: Mescal Canyon, 4800 ft., 2; Jackson Lake, 6000
ft., 1 (PC); San Antonio Canyon, 3900 ft., 1; San Antonio
Canyon, 2800 ft., 12.
=Pipistrellus hesperus merriami= (Dobson)