Background The Iberian/Pyrenean desman (Galemys pyrenaicus) is a small semi-aquatic mammal that is endemic to mountain streams in the Iberian Peninsula. The species is an excellent biological indicator with numbers reflecting closely the state of conservation or degradation of the habitats it occupies. However, the desman is increasingly in danger of extinction, with populations being both reduced and increasingly fragmented. The species is currently disappearing from the Sistema Central mountain range that covers the inner Iberian plateau and significant population decreases have been identified in the southern river basins of the Cantabrian mountain range. It has been catalogued by the IUCN Red List as a “vulnerable” species and is classified in some Spanish regions as “in danger of extinction”. Objectives The 'DESMANIA' project aims to establish the basis for a long-term strategy of recovery for the Iberian desman and its habitats. Ultimately, it hopes to change the negative population trend and improve the conservation status of the species, whilst also benefitting other species using the same habitat. The project will conduct an exhaustive study of the distribution, biology, behaviour (ethology), and genetics of the Iberian desman. In particular, it will examine and determine the causes of the regression of the species in the area, as well as defining risk maps of the high-priority habitats of the Iberiandesman. The project team plans to carry out actions to improve the status of the key habitats for the species in the SCIs covered by the project. They expect to establish measures to avoid and reduce the effects of the major identified threats, including invasive predator species, poor water quality and non-sustainable water use in natural channels. The project will involve and engage the relevant competent administrations and diverse social groups in the long-term management of the important habitat for the target species. It will work to increase awareness of the population of the existence of the Iberian desman and its role as a biological indicator of the quality of the water resource and the habitats that it occupies. Expected results: Increased understanding of the Iberian desman, its distribution, biology and its population regression; Identification and mitigation of major threats; Creation of a network for the long-term conservation of the species; Improvement in habitat quality at key sites for the species (including 88 km of river banks restored and 88.000 trees/shrubs planted); An increase in the Iberian desman population; Benefits to other species in the same habitat – in quantitative terms as well as biodiversity, improving the food chain; Increased awareness of the species and its biological indicator role; and The establishment of a basis for the future transfer of individuals to suitable habitat areas.