Mexican Free-tailed Bats

December 05, 2013


Photographer: Mike Zawaski; Mike's Web site
Summary Author: Mike Zawaski

Approximately 250,000 Mexican free-tailed bats take up residence during the summer months in the abandoned Orient Mine in the San Luis Valley, Colorado. Every day just before sunset the bats fly out of the mine and into the valley to feed, primarily on insects, before returning near dawn. Their mass exit produces a tube-like shape as the bats stream out from the cave before dispersing into the valley. The mine produced iron ore between 1880 and 1932. Evidently, the bats discovered this abandoned mine at least 40 years ago. Public access is free but requires a 45 minute hike up to the mine. Photo taken on August 5, 2013. 

Photo details: Camera Maker: OLYMPUS IMAGING CORP.; Camera Model: E-PL1; Focal Length: 30mm; Aperture: f/7.1; Exposure Time: 0.0016 s (1/640); ISO equiv: 800.