Distribution patterns and environmental determinants of European newts in the Montenegrin karst area

Abstract

The distribution patterns of three European newt species (Triturus macedonicus, Lissotriton vulgaris, and Mesotriton alpestris) was determined in the Montenegrin karst region and the influence of breeding ponds, the adjacent landscape, and climate variables on distributions within the framework of allotopy vs. syntopy occurrences was tested. After surveying 145 newt breeding sites in a 10,080 km(2) area, the ranges of T. macedonicus and M. alpestris were found not come into contact, while L. vulgaris, the most widely distributed species, covers the entire range of T. macedonicus and the lower part of the range of M. alpestris. Using Akaike's Information Criterion (AIC) to evaluate the effectiveness of 70 a priori models in predicting the presence of the three newt species, it was found that: (1) elevation is the most important variable in predicting newt presence; (2) only a few elevation-dependent variables can replace elevation in the building of a good descriptive model; (3) precipitation in combination with elevation contributes significantly to the building of a better descriptive model; and (4) in comparison with allotopy, syntopy mostly occurs at intermediate elevation ranges of species in sympatry.