First Records Of The Eastern Red Bat (Lasiurus Borealis) In Arizona, Utah, And Western New Mexico

Such records extend the known distribution of Eastern Red Bats farther west then previously recognized in the southwestern United States. In contrast, the seeming distribution for Western Red Bats is reduced in Utah by our findings. Identification of a red bat from south-central New Mexico was reexamined for which identification has been in question for years.

To assist researchers, an external morphological difference in fur coloration was described herein to aid in the identification of these two species in the future. Our study brings into question the identification of red bats formerly captured in the western United States, as our “new” records from Utah were collected in 1937 and 1991, and the “new” record from Arizona was from 1954. All red bats, including recent captures and museum specimens, from west of the Rocky Mountains need to be examined closely in light of our findings.

Recognizing how to identify these similar species will allow researchers to better understand their distribution, abundance, and migratory patterns, as well as provide better accuracy in call libraries for acoustic monitoring. Key words: Arizona, distribution, Eastern Red Bat, Lasiurus frantzii, Lasiurus blossevillii, Lasiurus borealis, migratory, New Mexico, state record, Western Red Bat, Utah