Coexistence and niche segregation in the newts

Abstract

AbstractThe newts Triturus vulgaris and T. cristatus are sympatric over almost the whole of their distributional areas, and they very often share the same breeding-ponds. According to "the competitive exclusion principle", however, no two species occupying the same ecological niche can persist together. Accordingly, within their habitat, the niches of the newts should be different. Studies on their macro- and microhabitat, diel activity, terrestrial seasonality and food, both of adults and larvae, indeed reveal such differences, especially in terrestrial seasonality, microhabitat and food preference. Although the habitat requirements of these newts are much the same, there is a clear resource partitioning between them, and adult T. cristatus also tends to exhibit a narrower niche breadth than does T.vulgaris.