Western Pipistrelle, Parastrellus hesperus
The western pipistrelle, commonly known as the canyon bat, is a one of over three hundred known species of evening (or vesper) bats. It can be found in the western United States and in Mexico, preferring to roost in small rock crevices around dry bush lands and deserts.
Known as the smallest bat in the world, males can be up to 2.5 inches, while females are slightly larger with an average of 2.8 inches. Its average weight is .1 ounces to .2 ounces. The western pipistrelle can fly up to five miles per hour, which is slow for its small size. The flight pattern of this bat is erratic, and can be compared to a butterfly. In 2006, the western pipistrelle received its own genus, Parastrellus, because it was not similar molecularly to its former genus of Pipistrellus.
Image Caption: Western Pipistrelle (Pipistrellus hesperus). NPS/Wikipedia