Shift of Population among Hibernating Bats

Abstract

The belief that the hibernation of warm-blooded animals is a continuous state of sleep or torpidity is now in general disrepute.There is much eviden which shows that hibernation is interrupted by periods of activity.Johnso (1931) studied the hibernation of the 13-lined ground squirrel and observe periods of waking and feeding.Observations on winter activity in hibernating bats have been made by Hahn (1908) in Indiana, Robin (1881), Rollina and Trouessant (1895) in France, Swanson and Evans (1936) in Minnesot and Guthrie (1933) in Missouri.During the fall and winter of 1937-1938 a study of bats in hibernation in New York State was made to see if different conditions of climate produced different habits of hibernation from those found by the other workers.Th cave selected for this study was the Indian Oven Cave in Ancram, near Millerton, New York, a few miles from the Tristate Corner of Massachusett Connecticut, and New York.The bats hibernating in this cave were almost entirely Myotis lucifugus, with occasional specimens of Myotis keenii septentrionalis, Myotis sodalis, and Pipistrellus subflavus.From October 2 to March 6, fifteen trips were made to the cave.I wish to acknowledge the assistance of Mr. and Mrs. Emerson Quaile of the Salis bury School, and Mr. Monroe Stearns of Washington, D. C., for makin these visits possible.Several students of the Salisbury School were particu larly helpful in making observations and assisting in banding activitie Donald R. Griffin of Harvard University made many valuable suggestions and lent me the complete data of his banding work on New England bats.The Indian Oven Cave is an extensive limestone fissure on top of a high ridge.It has two tall chambers, approximately 50 feet in height, connecte by a series of small chambers.Over the floor of the cave runs a brook, di appearing as a waterfall in a low, wide chamber at the end of the cave.Th last section is about 150 feet from the entrance.In the discussion to follow it