WESTERN YELLOW BAT - Lasiurus xanthinus

Weight: 10-15 grams

Wingspan: : 33-36 centimeters.

Distribution: Southwestern United States across the Mexican Plateau to southern Mexico.

Ecology and Behavior: Little is known regarding habitat, but like other lasiurine bats, it roosts in leafy vegetation. Ecologically it seems to be associated with the dry thorny vegetation of the Mexican plateau, coastal western Mexico, including parts of Baja California, and the deserts of the southwestern United States. In New Mexico, it is known to roost in hackberry and sycamore trees. In Arizona, some apparently hibernate among the dead fronds of palm trees, as several were found in these trees in Tucson during January and February. This bat may be extending its range in the United States as evidenced by its appearance at several sites in Arizona in recent years. Recent studies have shown this species is genetically different from the southern yellow bat (Lasiurus ega).

Food Habits: It consumes small to medium-sized, night-flying insects.

Reproduction: Usually two babies are born in June, but the presence of up to four embryos suggests that size of litter may vary from two to four.

Status of Populations: Common in southcentral Arizona, but uncommon elsewhere in the south­, western United States.

Thanks to T. L. Best, J. S. Altenbach, and M. J. Harvey for permission to reprint portions of Bats of the Western United States, 1998.