Acta Zoologica Cracoviensia, 11() 1966
Kumaki (Bombina Oken, 1816) Beskidu Niskiego i terenów przyległych
[Balied Toads (Bombina Oken, 1816) of the Beskid Mts. and the adjoining regions]
Abstract:
SUMMARY. The purpose of the present study was to examine the variation and geographical distribution of Bombina in the Low Beskid Mts. and the adjoining regions so as to throw some light upon the unexpectedly great variation of these animals in the Sądecki Beskid Mts., especially in its highest parts. This last fact was stated in the previous paper of the author (Madej, 1964b). In addition, the variation of Bombina in the Low Beskids excited attention on account of the remarkable geomorphological and climatic distinctness of this section of the Carpathian arch, as compared with the other parts of the Beskids. The study area includes the Low Beskids, the so-called Doły Jasielsko-Sanockie, and the Low Beskid Upland. A total of 582 specimens of Bombina were collected at 70 localities all over this area. The material was classified by the method described in an earlier paper of the author (Madej, 1964 a). The results of classification are given in Tables 1 and 2. The map illustrates the geographical distribution of Bombina. The localities plotted on the map show the degree of variation of specimens taken there (I, II, III, IV), and are marked by numbers (1-70) corresponding to those used in Tables 3-6. The analysis of material shows that the study area is inhabited by a population of the yellow-Bellied Toad (Bombina variegata) (Linnaeus) distinguished by conspicuously great variation, characteristic only of the transition zone between the ranges of both these species in the other parts of the Beskid chains and uplands. This variation is greatest in Bombina of the „Doły Jasielsko-Sanockie“ and the central and western regions of the Low Beskids. It is smallest in the specimens from the eastern part of the Low Beskids. The singularities of the occurrence of Bombina in the study area are as follows: a) The reversed correlation between variation and the altitude, as compared with the other regions of the Beskids; the higher a locality is situated, the greater is the admixture of the fire-bellied toad’s characters, b) The abundance of localities in wooded areas and their scarcity or even lack in woodless regions, c) The far more frequent occurrence of Bombina in beds of rivers and streams than in the other parts of the Beskids. For the causes of the uncommonly great variation in Bombina of the Low and Sądecki Beskids the author refers to the Pleistocene and Holocene history of these areas, their specific geomorphological and climatic conditions, and the migrations of both Bombina species in the postglacial period. The author concludes that in the postglacial period these regions were inhabited by the fire-bellied toad, which next was ousted by the yellow-bellied toad. The great variation of the Bombina population in these areas persisting up to the present time is a relict of the mass interspecific crosses that took place at that time. The distinct connection of the density of Bombina localities with wooded areas and the frequent occurrence of Bombina in river-beds are, in the author’s opinion, due to the very low dampness of these regions, as compared with the High and the Śląski Beskids.
