THE HOMING BEHAVIOR OF CORYS SHEARWATERS (CALONECTRIS-DIOMEDEA) STUDIED BY MEANS OF A DIRECTION RECORDER

A direction recorder, which can be carried by a flying bird on its bac k, has been used for the first time on a wild species. The device can detect and record the direction in which a bird is heading during flig ht, Cory's shearwaters (Calonectris diomedea) were moved from their ne sting colony to five different sites and fitted with direction recorde rs, and four homing flight paths were obtained. Our data show that the displaced birds were able to assume and maintain a homeward course so on after release over large areas of open sea, completely devoid of gu iding features; topographical elements are, therefore, not necessary f or correct orientation.