This article shows what method is suitable for an accurate determination of the annual rhythmics of lizard species. Such a determination can be reached with the help of, amongst others, mating scars, presence of deep skin folds and the structure of the navel scars in juveniles. This method was applied in a five year intensive poulation study on Lacerta vivipara and Lacerta agilis agilis in the south-east of the Netherlands. The data on rhythmics obtained thus are discussed.
A telemetric system suitable for radio tracking anuran species is described. Its characteristics are given in detail, which will enable electrical engineers to construct the various elements. The system proved to be successful in field tests with Bufo bufo bufo L.