EDP Baixo Sabor: Iberian Desman (Galemys pyrenaicus) – Construction [2012-2014], Reservoir Filling [2015] and Operation (2015-2020] Phases

Sampling was designed to cover the whole valley of the lower Sabor river, its tributaries and rivers Maçãs and Angueira and Vilariça stream. A total of 80 transects (60 in 2012-2014 and 20 in 2015-2020) was established in the study area. The transects had a minimum length of 200 m and, within this distance, the prospection ceased after the detection of the first confirmed sign of presence of the species. If there were no evidences of presence in the first 200 m the transect was extended to a maximum of 600 m, after which, if the absence of signs persisted, the species was considered as absent in the transect. Each transect was performed on foot, during daytime, by one or two observers, and the riverbed and its margins were carefully searched for signs of the desman’s presence (scats, footprints). Because the position and length of the transects could change between seasons and/or years in function of the prevalent field conditions, only the initial point of each transect was retained in this dataset. All scats found were identified in the field and taken to the laboratory to validation. In 2012-2014 this was performed by the traditional methodology of detecting the presence of the species hair (always present in the scats of this insectivorous mammal): the scats were broken down in water and observed with a magnifying glass. Hair identification was performed with the help of appropriate mammal hair identification guides. From 2015, the collected scats were sent to a certified laboratory to be subjected to molecular analysis with specific primers for Galemys. This method was used in combination with the hair analysis, whenever the results of the molecular analysis were inconclusive.