Mammal · Alps & Pyrenees
Galemys pyrenaicus
● IUCN: Endangered · strictly protected
An animal like a mole, with a long, flexible trunk-like snout, webbed hind feet and a long tail. The Pyrenean desman lives only in cold, clear mountain streams in the Pyrenees and the north-west of the Iberian Peninsula. Hardly anyone has ever seen one, and it is becoming ever rarer.
| Habitat | Fast-flowing, oxygen-rich mountain streams with stones and undercut banks |
| Length | Body 11–13 cm, plus a tail of about the same length; 50–80 grams |
| Active | Mainly at night, all year round |
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Ecological profile
| Identification | Small, dark-brown animal with a long, flat trunk-like snout, tiny eyes, large webbed hind feet and a long, scaly tail |
| Family | Not a rodent, but a relative of the mole |
| Diet | Aquatic insects and their larvae, such as caddisflies, mayflies and stoneflies |
Where can you find them?
Difficulty: ●●●●● Rare chance
The desman is small, shy and mainly active at night. Even researchers usually find only its droppings on stones in the stream.
| France | Mountain streams across the French Pyrenees, from the Basque Country to the Pyrénées-Orientales |
| Also | Northern Spain, Andorra and northern Portugal |
| Tip | Look at the stream rather than for the animal: clear, cold, fast water with plenty of stones is its home |
Did you know the desman hunts underwater mainly by touch? Its trunk-like snout is packed with sensitive touch receptors, which it uses to search for larvae among the stones.
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Behaviour & seasons
The desman leads a hidden life. By day it rests in a burrow in the bank or among tree roots and stones. At dusk and at night it dives into the stream, each time for just a few seconds, to search for larvae among the stones. Each desman has its own stretch of stream a few hundred metres long. It does not hibernate and is active all year, even in ice-cold meltwater.
| Winter | Active under ice and in cold water; no hibernation |
| Spring | Breeding; the young are born in the bank |
| Spring – early summer | High water from melting snow |
| Summer – autumn | Low water; young desmans look for a stretch of their own |
When is the best time to see them?
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| cold or high water | low water · signs easiest to find | winter | |||||||||
■ Good chance ■ Fair chance ■ Difficult
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Threats & protection
In 2021 the IUCN listed the Pyrenean desman as Endangered. In the French Pyrenees its range has shrunk by around 60 percent. Hydroelectric plants and dams change the flow and cut streams into pieces. Add pollution, water extraction, drought driven by climate change and non-native animals such as the American mink and American crayfish.
What is being done? France has a national action plan for the desman, and with European LIFE funding its streams have been mapped and dam operators brought on board. As a walker you can help by leaving stream banks intact and not damming streams or moving stones.
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Stories & culture
The trumpet rat
In the Pyrenees it is called rat-trompette, the trumpet rat, after its long snout. But it is not a rat: it belongs to the mole family. The French naturalist Étienne Geoffroy Saint-Hilaire first described it in 1811. Together with the Russian desman, it is the last species of an ancient group of water mammals that once lived across much of Europe: a living fossil in the streams of the Pyrenees.
Frequently asked questions
Questions about the Pyrenean desman
Is a desman a rat?
No. Despite its nickname ‘trumpet rat’, the desman is related to the mole, not the rat.
Where does the Pyrenean desman live?
Only in the Pyrenees and the north-west of the Iberian Peninsula, in cold, clear, fast-flowing mountain streams.
Why is the desman endangered?
Mainly because of dams and hydroelectric plants, pollution, water extraction, drought and non-native predators such as the American mink.
Habitat · France
