Yuma Bat Catching a Moth
(Click on the image to see a larger image)
Photo © Merlin Tuttle
Description: Wingspans ranging from 8” to 11”. 2 ¼” body, 1 3/4” tail. Weighs an average of 6 grams, approximately a nickel’s weight. Yuma Bats have a narrow adaptation for reproduction, with the pregnant females dependent on forming large maternity colonies together rather than dispersing in small groups to give birth and rear their young.
Spring/summer: At Woodard Bay about 70% of the 3000+ pregnant female bats roosting there under the railroad trestle are Yumas, a much more rare species than the Little Brown Bats sharing the roost with them. Most of the Yumas also migrate every night to Capitol Lake to feed, joining other Yumas coming along the other “bat highways” to the lake. The males are thought to live at higher altitudes in forested areas.
Fall/winter: Migrates to unidentified winter hibernation sites, probably to higher and colder areas within a couple hundred miles of Thurston County.