Geographic Variation of the Yellow Bellied Toad (Bombina variegata) (L.) from the Carpathian Mountains of Romania and the USSR

Abstract

New data on variation in biometrical features and color patterns of Bombina variegata are presented. Eight forms are distinguished according to the amount of yellow and black on the ventral body surface. The amount of coloration varies from a continuous yellow field to a continuous black one with all possible intermediates. Toads with a predominantly yellow ventral surface are more frequent in the southern parts of the species range. Toads with a predominantly black undersurface are more frequent in the northern parts of the species range. It is believed that the eight described color forms are due to random mutations but their geographic variation and frequency seem to be under environmental control.