An isolated crested newt population in Dutch coastal dunes: distribution relict or introduction?

Abstract Isolated distribution patches may represent local remnants of a formerly wider range or could have originated by human-mediated expansion beyond the natural range. Distinguishing between these two scenarios is not always straightforward. Northern crested newts ( Triturus cristatus ) in the Dutch coastal dunes are disconnected from the main species range by over 40 kilometres and whether they have been present historically is unclear. We genotyped crested newts from throughout the Netherlands for an mtDNA marker to determine the provenance of the coastal dune population. Because a clos... Mehr ...