Temporal spacing of breeding activity in the natterjack toad, Bufo calamita.

摘要: The reproductive behaviour of the toad Bufo calamita was studied in a large population northern Rhineland, Germany. Toads bred at four spatially separated but neighbouring areas including 34 breeding ponds. Three methods were applied to monitor quantitatively intensity and migratory activity: capture-mark-recapture, mechanical tracking device, radio-telemetry. In 1987 twofold temporal spacing activity observed: (1) division period into early, main, late periods; (2) subdivision each several short calling periods. Since weather conditions favourable during most period, environmental factors contributed little (23.4%-41.0%) variation as shown by multivariate statistics. vocalization (April August) included three distinct male groups. first group called from April mid-May (2 periods), second May early July (5 periods) third mid-July August periods). Within males stayed near their sites low. Extensive movements detected when new immigrated feeding regions that had been previously emigrated, least partly. However, exchange among choruses clearly audible. It is suggested energetic costs impeded continuous individuals accounted for periodical variations chorus size. short-time therefore probably reflect physiological limits toads situation where permits activity.