A morphometric study of a hybrid newt population (Triturus cristatus/T. carnifex): Beam Brook Nurseries, Surrey, U.K.

Abstract

The crested or great crested newt (Triturus cristatus spp) is declining and now considered threatened in many of the countries where it is present. This has resulted in the four members of the superspecies being afforded protection under local, national and international law. This study looks at a possible threat to T. cristatus in southern England through hybridization, by the introduction of a related alien species (T. carnifex). The study used multivariate morphometrics to discriminate closely related species, and their hybrids. The character set involved both continuous and meristic data, collected through body measurements and colour pattern. The identification of the species and/or hybrids at the introduction site and surrounding areas was mapped. From the results it can be inferred that hybridization has taken place at the introduction site, but there is no morphological evidence for the spread of hybrids/aliens in to the surrounding areas.