Predation and competition within an assemblage of larval newts (Triturus) |
| |
Authors: | R. A. Griffiths P. de Wijer R. T. May |
| |
Affiliation: | The Durrell Inst of Conservation and Ecology, Kent Research and Development Centre, Univ of Kent, Canterbury, Kent, CT2 7PD, England |
| |
Abstract: | The impact of crested newts (Triturus cristatus) on the smaller-bodied palmate and smooth newts (T helveticus and T vulgaris) was studied during the larval stages using a combination of field and laboratory experiments In pond enclosures T cristatus larvae had no effect on the two smaller species over the first four weeks of development By eight weeks, however. T cristatus had achieved a size advantage which enabled it to eliminate T helveticus and severely reduce T vulgaris by predation In laboratory trials under food-limited conditions, T helveticus and T vulgaris were slightly smaller when raised with T cristatus, suggesting that this predatory effect was complemented by interspecific competition during early development Predation of the smaller species started when T cristatus reached a threshold size of c 27 mm No reciprocal effects on T cristatus growth or survival were observed Although T cristatus may be a significant predator of congeneric species in natural ponds, other factors, such as differences in microhabitat selection, higher-order predator-prey interactions and the occasional desiccation of pond habitats may facilitate coexistence between the species |
| |
Keywords: | |
|
|