The invention relates to a device for restraining at least one body part of a living bird for recording characteristic vibrational spectra. The device has a relief mask for inserting the body part to be restrained, at least one movable holding arm which is provided for restraining the body part, and a sensor access with a light channel for guiding the excitation light emitted onto the restrained body part from a light source and for recording the light scattered back by the restrained body part. The invention further relates to devices and methods for determining the sex of living birds.
