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-activity rhythm. A nycthemeral component was found in the rhythms of all individuals investigated, both juveniles and adults at the various stages of the reproductive cycle. In contrast, ultradian rhythms were typical of immaturity; they were present in juveniles and in females accompanied 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 according 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 behavior.