The storage telemetry system ETHOSYS has been applied to ruminant and non-ruminant species in close to natural conditions. It was designed for automatic recording of different behaviors, such as motor activity and feeding [3]. Species-specific activity patterns became visible. They show a high number of short activity peaks in roe deer, a lower number of peaks in red deer and mouflon and very long peaks in Przewalski horses. These patterns can be explained by the different nutritional strategies of the species. In red deer, the ultradian rhythms differ seasonally reflecting the variable feeding strategy of an intermediate feeding type species [2].

In Przewalski horses the frequencies of the ultradian rhythms are nearly unchanged in course of the year. However, Przewalski horses change the daily level of activity and feeding throughout the year, depending on the feeding conditions. A stable ultradian structure of behavior became obvious especially for ruminants. A more unstable, adaptive time pattern was found in Przewalski horses [1]. Activity as a multi-purpose behavior was generally more variable than feeding which, in most cases, had a clearly rhythmic and harmonic structure. A high percentage of activity periods harmonic to the 24-hour-rhythm seems to be characteristic for a healthy and undisturbed individual. In several occasions, external disturbances or social stress resulted in a substantial decrease of this percentage. A measure was developed based on the power spectral analysis to quantify the functional frequency order of circadian and ultradian rhythms. It could be used to determine the influence of hunting and shooting, low social state and human activity.

References

1. Berger, A.; Scheibe, K.M. (1995). Aktivitätsrhythmik bei Przewalskipferden (Equus przewalskii) unter seminatürlichen Lebensbedingungen. Orn. Beob., 92, 359-360.
2. Berger, A.; Scheibe, K.M.; Eichhorn,K. (1995). Untersuchungen zur Biorhythmik der Aktivität und Nahrungsaufnahme beim Przewalskipferd (Equus przewalskii) und beim Rothirsch (Cervus elaphus). Z. Säugetierkunde, 60, Suppl. 6.
3. Scheibe, K.M.; Schleusner, T.; Berger, A.; Eichhorn, K.; Langbein, J.; Dal Zotto, L.; Streich, W.J. (1998). ETHOSYS - new system for recording and analysis of behaviour of free-ranging domestic animals and wildlife. Appl. Anim. Behav. Sci., 55, 195-211.