The Herpetological Journal

pp.1-8

Authors: John M. R. Baker

Abstract: A population of great crested newts ( Triturus cristatus) in central England was monitored from 1 988- 1995. Recognition of individuals was used to quantify population dynamics. Adult annual survival varied from 31-100%. Long-term members of the breeding population had a significantly higher rate of annual survival (65%) than individuals breeding for the first time (57%). The population showed variable patterns of recruitment. A period of six years with little recruitment was followed by a rapid increase in population size, more than three-fold, over two years. The change in the population characteristics coincided with a crash in the population of predatory three-spined sticklebacks (Gasterosteus aculeatus), raising the possibility that newt recruitment was held in check by predation. Juveniles were rarely captured, but their recapture rate between years ( 49%) indicated that the rate of annual survival for juveniles in this population could be relatively high (estimated as 59%). Most juveniles matured at two years of age. The study population thus consisted of long-lived adults, showing variable survival, and erratic recruitment. The longevity of adults enabled the population to persist under adverse conditions until beneficial circumstances could be exploited by rapidly increasing the population size. These demographic traits may be common in T. crislatus populations.

Keywords: Triturus cristatus, population dynamics, mark-recapture