The pallid bat is probably the most common and characteristic bat of the
citrus belt at the Pacific base of the mountains. Only once, on May 4,
1951, was this bat taken in the mountains. On that night two individuals
were collected at 2800 feet in San Antonio Canyon. All of the other
specimens and observations were from colonies in old barns and
outbuildings in the citrus belt where these bats are found in spring,
summer, and fall.
The impression gained by examining many mixed colonies of _Antrozous_
and _Tadarida_ was that the former greatly outnumbered the latter. For
example, a small colony of bats in an old barn near San Dimas Wash
consisted of about thirty pallid bats and five freetails.
Large numbers of wings of moths of the family _Sphingidae_, and legs and
parts of the heads of Jerusalem crickets (_Stenopelmatus fuscus_) were
beneath an _Antrozous_ night-roosting place in a barn near Upland.
Pallid bats were collected in 1951, from April 16 to October 17 but
probably were active in the area into November.
Each of two pregnant females taken two miles northeast of San Dimas on
April 20, 1951, carried two embryos 4 millimeters long.
_Specimens examined._--Total, 6, distributed as follows: Los
Angeles County: 2 mi. NE San Dimas, 1200 ft., 2 (1PC); Ontario,
1100 ft., 4 (3PC).