Dispersal and alternative breeding site fidelity strategies in in the great crested newt

Submitted by editor on 7 December 2017. Get the paper!

By: Mathieu Denoel

We aimed at examining whether distinct breeding site fidelity strategies may coexist at the intra-population level and how breeding resource characteristics and individual phenotype may affect these strategies in pond-breeding amphibians.

To this end, we took advantage of recent developments in multi-event capture-recapture models but also RFID telemetry to examine breeding dispersal in 946 marked great crested newts (Triturus cristatus) over a network of 73 ponds.

Our study revealed the existence of a dispersal polymorphism at the population level in the crested newt. We highlighted the coexistence of two dispersal phenotypes, namely, a highly site (i.e. pond) faithful phenotype and a lowly site faithful phenotype (i.e. a dispersing phenotype) at both intra and inter-annual scales. Breeding site infidelity was unexpectedly very high at both of them. Our results also showed that the probability that individuals belong to one or the other dispersal phenotypes depended on environmental and individual factors. In particular, we highlighted the existence of a dispersal syndrome implying a covariation pattern among dispersal behavior, body size, and survival.

Our work opens new perspectives on our understanding of newt movement in the framework of habitat supplementation and complementation. More broadly, it highlights new research prospects in the evolution of dispersal in organisms displaying complex life cycles and raises interesting questions about the evolutionary pathways that contribute to the diversification of movement strategies in the wild.