Transistor Equipment for Continuous Recording of Oriented Migratory Behavior in Birds

The migratory behavior of birds has been studied for over 30 years, but a more precise measurement of this behavior is needed to aid in the study of orientation and navigation during migration. The equipment developed for this purpose consists of eight small cages arranged along the axis of the major points of the compass and opening into a large center area. Each cage is provided with a transducer which responds to vibrations induced by a bird in that cage. A "count" is recorded and automatically printed at regular intervals from each cage, giving a permanent record of the bird\´s activity. Preliminary results indicate the system will provide reliable data on magnitude and orientation of a bird\´s activity. Data are presented for a bird in the natural migratory state and ones in which this state has been artificially induced or maintained.