National Geographic : 1946 Jul
Mystery Mammals of the Twilight Staff Photographer Robert F. Sisson Into Such Small Black Holes in Hillsides Bats Fly Unerringly "by Ear" Truly remarkable are the creature's powers of avoiding obstacles that beset his path in gloomy woods and pitch-black caves. So skillful is his flight, indeed, that some have credited him with a sixth sense, while the hard-headed practical scientists have only recently discovered that his powers are based upon echolocation, a mode of perception operating on the same principles which underlie some of the most complex devices yet produced by man (page 133). Here Dr. Griffin, emerging from an old mine near Pepperell, Massachusetts (page 121), hands a colleague a wire container of bats. would be far too cold in midwinter, and these breeding colonies which were so full of bats in July are deserted by the end of September. The logical deduction is that they migrate to the nearest caves for the winter and return again the next summer. Banding the Elusive Bat in Its Lair It was my interest in this problem of bat migrations that led me to begin banding cave bats in both summer colonies and caves in New England about 14 years ago. By handling thousands of bats at all seasons, we found it possible to recapture some at a dis tance from the place where they were originally taken and thus to establish the direction and extent of migration. Most of this work was done in spare time and on week ends snatched from the busy college life of a group of Harvard students. More than thirty men have participated in one or more of the trips to bat caves, but the outstanding ones, known among themselves as "master bat banders," are T. L. Perry, H. B. Hitchcock, Garrett Eddy, F. L. Osgood, G. E. Folk, Robert B. Holden, David McAllester, and Douglas Robinson. Special equipment, most of it built for the purpose, is loaded into whatever cars are available, and the expedition is off for the hills (page 121). We had to spend much time in searching for caves, and many disappoint ments were our lot when some "enormous cavern" we had been told about turned out to be a measly porcupine hole barely ten feet long and two feet high. All bat banding in caves must be done in winter and despite whatever weather New England's fickle winds may blow. Snowshoes and skis have been needed often.