Distribution of some daily and seasonal events in relation to changes of physical factors

Abstract

A special case of the Weibull distribution model is used in describing the course of behavioural transformation processes in relation to some cyclic physical factor. The model assumes that the rate of the process increases, the less inhibiting the physical factor, and the faster the factor changes. However, due to some resistance or a depletion, the rate slows down, the further the process progresses. The model was tested on the daily onset of activity in nocturnal insects, daily roosting flight of blackbirds, dark and light adaptation by pigment migration in insect eyes, photoperiodic response of an insect, and daily emergence of tiger beetles. The assumptions of the model are tested and discussed. One of these is violated in unnaturally fast changes of the physical factor because the process reaches some constant minimum duration, and proportionality between rate of process and rate of factor can no longer be maintained.