The diet of the Rhone apron: a feedback of an innovative study of dietary metabarcoding

Abstract

Dietary studies are essential for determining the trophic habitat requirements of a threatened species, particularly to guide its management, conservation or restoration. Within the framework of the National Action Plan for the Rhone apron (2012-2016), we have developed and used an innovative molecular method (metabarcoding) to determine and quantify the diet of the apron from its faeces. In parallel, we conducted intensive sampling of river microhabitats in order to characterize the community of potential apron prey (abundance, occurrence and physical habitats of benthic macroinvertebrates). This approach allowed us to acquire a very precise knowledge of the trophic requirements of the apron in terms of prey and habitats. It has also highlighted the decisive role played by the diversity and structure of the macroinvertebrate community on seasonal variations in the diet and condition of the apron. Our study has thus highlighted some key parameters for a better management of the carrying capacity of its habitat.