Using eDNA presence/non-detection data to characterize the abiotic and biotic habitat requirements of a rare, elusive amphibian

Abstract

The environmental DNA (eDNA) approach has already been established as a valuable tool for the detection and monitoring of rare and elusive species. However, its application is not limited to assessing whether or not a species is present in a given area. In this study, we collected environmental data from 48 aquatic locations that had previously been investigated in an eDNA-based study. We sought to determine the abiotic and biotic factors that could explain the presence or non-detection of Hula painted frog DNA at those locations, in order to characterize this rare species’ little studied habitat requirements. We found that the detection probability of this species decreased substantially with increasing phosphorus loads as well as in the presence of the wetland plant Lythrum salicaria. By contrast, the detection probability increased markedly when Phragmites australis or Ludwigia stolonifera constituted part of the dominant aquatic vegetation. Our results expand the knowledge on this elusive frog species and contribute valuable information for future habitat restoration plans. They further show that eDNA data can also be used to characterize the putative habitats of species where such data are scarce or even totally lacking.