||The Mammals of Texas -
Chiroptera : Family
Vespertilionidae : Myotis yumanensis (H. Allen)
Description. A small bat similar to M. lucifugus; feet relatively large, more than half as long
as tibia; ratio of tail to head and body more than 80;
coloration dull, pale pinkish, or cream buff; immature
individuals darker, nearly cinnamon buff; membranes pale
brownish; underparts pale buff, nearly white; pelage
short as compared with M. lucifugus; viewed from
the side, the skull rises more abruptly from the rostrum
than in M. lucifugus; dental formula as in M. californicus. External measurements average: total length,
78 mm; tail, 34 mm; foot, 8 mm; forearm, 34 mm.
Distribution in Texas. Restricted in
Texas to the southern Trans-Pecos and Rio Grande Valley.
Habits. Surprisingly little
information is available on the habits of this species in
Texas. It is primarily an inhabitant of desert regions
where it is most commonly encountered in lowland habitats
near open water, where it prefers to forage. It roosts in
caves, abandoned mine tunnels, and buildings. In the Big
Bend region of Texas, it is common in summer along the
Rio Grande where it comes to drink just after sundown.
Its flight is fluttering and erratic, as it is in other
members of the genus. No winter records are available for
Texas, and it is unknown whether theYuma myotis
migrates or overwinters in the state during this season.
The stomachs of bats captured in Big
Bend National Park contained moths, froghoppers and
leafhoppers, June beetles, ground beetles, midges, muscid
flies, caddisflies, and craneflies.
The season of partus is from May to
early July, and usually only one young is born to each
Photo credit: Merlin D. Tuttle, Bat Conservation