The present invention relates to an apparatus for locking at least one body part of a living bird in position for recording characteristic vibrational spectra, wherein the apparatus comprises a relief mask for inserting the body part to be locked in position, at least one movable supporting arm provided for locking the body part in position, and a sensor access with a light channel for directing the stimulation light irradiated by a light source onto the locked body part and for collecting the light back-scattered by the locked body part. The present invention further relates to devices and methods for determining the sex of living birds.
