Genetic monitoring of the endangered Pyrenean desman (Galemys pyrenaicus) in the Aude River, France

The Pyrenean desman (Galemys pyrenaicus) is a small semi-aquatic mammal endemic to the Pyrenean Mountains and the northern half of the Iberian Peninsula. This species is currently considered as vulnerable in the IUCN Red List and has been suffering from habitat loss and fragmentation for decades but little is known about the impact of water flow modifications induced by hydroelectric power plants. In order to address this issue we monitored Pyrenean desman individuals living in a harnessed section of the Aude River, by genotyping both faeces samples and hair of live-trapped animals. During a three-year study (2011-2013), a total of 39 individuals were identified using 24 microsatellite loci, 28 from faeces and 11 from trapped animals. Several long distance movements were evidenced up to at least 15 km, a distance that has never previously been reported. These movements might be related to modifications of the river bed caused by very high water flows that occurred during the repair of the Nentilla hydroelectric plant. The local population density suggests that the Aude River provides suitable habitat for the Pyrenean desman, and preservation of this habitat should be a priority for the conservation of this species.