The Iberian desman has lost about 69% of its range in three decades

The Iberian desman (Galemys pyrenaicus) has lost about 69% of its range over the past three decades. The figure, which comes from the IUCN Red List, was presented by geneticist Luis J. Royo, of the University of Oviedo, at the scientific conference of Sierra de Guadarrama National Park.

An animal hardly anyone knows

It’s a relative of moles that lives in mountain rivers and exists only on the Iberian Peninsula. Its body is 11 to 16 cm long, and its tail about the same. It has a long, mobile snout it uses to find larvae under stones.

It’s so little known that, in a 2026 BBVA Foundation survey, nobody named it unprompted among threatened species.

Looking for its DNA in the water

Because it’s small, nocturnal and hard to spot, the Oviedo team looks for its genetic trail. It places capsules with gauze in the river to trap the DNA carried by the current.

According to the talk’s data, reported by ECOticias, they sampled 21 points on four northern rivers (Espinaredo, Narcea, Pigüeña and Teverga), and 26 of the 83 valid samples were positive. Digital PCR found DNA where classic PCR couldn’t.

The study is still under review at a scientific journal, so these results aren’t final yet.

What threatens it

• Dams, reservoirs and channelling that change the river.
• Loss of riverside vegetation.
• Pollution and climate change.
• The American mink, an invasive species that keeps spreading.

The team notes that the species has five distinct evolutionary units that should be managed separately, and its next step is to measure whether dams isolate populations from each other.

Removing barriers helps rivers: Europe removed 603 dams in 2025.