ONTOGENY OF THE REST-ACTIVITY RHYTHM IN THE WILD BOAR

Continuous biotelemetry records of the wild boar (Sus scrofa L.) under natural conditions were used to study the ontogeny of its rest-activi ty rhythm. A nycthemeral component was found in the rhythms of all ind ividuals investigated, both juveniles and adults at the various stages of the reproductive cycle. In contrast, ultradian rhythms were typica l of immaturity; they were present in juveniles and in females accompa nied by unweaned piglets and disappeared in adult females with weaned piglets or without piglets and in adult males. The detected ultradian rhythms had periods of approximately 3 hours or multiples of 3 hours a ccording to age for juveniles and to the lapse of time since farrowing for females. Results are discussed with respect to uniform influences of internal processes and environmental factors on the individual beh avior.