||The Mammals of Texas -
Chiroptera : Family
Vespertilionidae : Antrozous pallidus (Le Conte)
Description. A rather large, pale,
yellowish-brown bat. Ears about 2.5 cm long, broad,
naked, and crossed by nine or 11 transverse lines; bases
of hairs light (nearly white), tips dusky; large light
spot between shoulders; underparts paler and lacking
dusky-tipped hairs; membranes nearly naked and brownish;
nostrils surrounded by a glandular ridge producing a
blunt snout; feet relatively large and strong. Dental
formula: I 1/2, C 1/1, Pm 1/2, M 3/3 X 2 = 28. External
measurements average: total length, 113 mm; tail, 46 mm;
foot, 12 mm; ear, 28 mm; forearm, 48 mm. Weight, 12-17 g.
Distribution in Texas. A common resident
of the western one-half of Texas where two distinct races
are known: A. p. bunkeri in the northern Panhandle
and A. p. pallidus in the west and south.
Habits. Pallid bats inhabit
rocky, outcrop areas where they commonly roost in rock
crevices, caves, and mine tunnels but they also roost in
the attics of houses, under the eaves of barns, behind
signs, in hollow trees, and in abandoned adobe buildings.
Colonies are usually small and may contain 12-100 bats.
Pallid bats usually appear on the wing relatively late at
night, well after dark. The species is probably migratory
although occasional individuals have been reported from
the United States in winter.
Their feeding habits are unlike those
of most American bats. For years naturalists have noted
the kitchen middens of discarded wings and other hard
parts of insects under their "feeding roosts."
Among them were remains of Jerusalem crickets, scorpions,
and other flightless arthropods, although their diet also
includes flying insects. To some extent though, pallid
bats are terrestrial foragers. They have been observed
flying, apparently at random, over an area at levels of
15-90 cm above the ground. When prey is located,
presumably by sight, the bat abruptly drops to the
ground, searches briefly, grabs its victim in its mouth,
and takes off. Captured prey is taken to a feeding
station where it is consumed. A. E. Borell described how
one of these bats consumed a grasshopper. While eating,
the bat hung head upward, supported by the thumbs, with
the wings partly spread. The legs held the posterior part
of the body well out from the timber and with the tail
curved forward against it; the interfemoral membrane
formed a pouch to catch parts of the large insect as they
Other than the items mentioned above,
pallid bats also eat moths, froghoppers and leafhoppers,
June beetles, and grasshoppers. In fact, 54 different
types of prey have been documented for the pallid bat.
Large, night-flying insects and ground-dwelling
arthropods are most prevalent in the diet, however.
Mating occurs in fall with parturition
in early summer. Females may carry one to four embryos
but the birth of twins is usual. The length of gestation
is 53-71 days. In Texas, the baby bats are born in early
May to mid-June. Newborn bats weigh approximately 3 g and
seem to develop more slowly than other species. The eyes
open at 8-10 days of age, hair is evident at 10 days, and
the young are volant by 6 weeks of age. Young bats have
been found to contain both milk and insect remains in
their stomachs, indicating that the young continue to
nurse after becoming volant.
Photo credit: Merlin
D. Tuttle, Bat Conservation International.
This page is copyrighted ©1994 by Texas Parks
and Wildlife, Nongame and Urban Program. All rights
reserved. Used in this online edition with
permission. Page maintenance by the Natural
Science Research Laboratory at
Texas Tech University. Last updated on 24 December 1997.
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