There has been considerable speculation in the past concerning the nature of population movements of the Mexican freetail bat, Tadarida brasiliensis mexicana. Some have contended that seasonal movements are purely local, while others have insisted that the activity is of a truly migratory nature. To date the only positive evidence supporting the latter view has been the recovery of a single band which was placed on a bat by Richard G. Prasil at Carlsbad, New Mexico, and was recovered in Jalisco, Mexico, approximately 800 miles to the south (Villa and Malaga-Alba, Some notes on the distribution of North American bats, etc.; read before the American Society of Mammalogists, June 16,1956).