Abstract: A storage telemetry system has been developed to monitor domestic animals and wildlife, and has been tested under variable conditions on sheep, Przewalski horse and mouflon. It can be used for automatic recording of different patterns of behaviour, such as activity and feeding, and is based on advanced analysis of sensor-emitted signals. The system is made up of collars (ETHOREC) with sensors and electronic devices for behaviour recording, a central station (ETHOLINK) and software for data transmission and processing (ETHODAT). All components of the ETHOREC recording device are integrated in the collar. Long-time recording of behaviour through up to four different channels and in numerous animals at one and the same time are necessary elements to facilitate biorhythmic analysis of animals under free-ranging conditions. The results obtained from this telemetry system were compared with visual observations on six sheep and four Przewalski horses. Parallel recordings were taken from four sheep, using a recorder for jaw movements. Locomotor activity usually was rated somewhat higher by observers, whereas feed uptake was rated lower. Higher feed uptake values were measured by means of the jaw movement recorder, although deviations thus measured varied less than those noticed by visual observations. All measured series exhibited significant correlations with control values. The system, consequently, was found to be more suitable for determination of diurnal patterns, change over time and relative comparison between behaviour levels than it actually was for measurement of absolute duration of a given behaviour.