Elusive, aquatic and wonderfully odd, the Pyrenean desman (Galemys pyrenaicus) is one of Europe’s most mysterious mammals.
Found only in the fast-flowing mountain streams of the Iberian Peninsula and southern France, this small insectivore leads a secretive, nocturnal life. With a flexible trunk-like snout, webbed feet and waterproof fur, it’s perfectly adapted to life underwater.
Rarely seen in the wild, its presence is often only known through camera traps and environmental DNA.
As human activity threatens its fragile habitat, conservationists are racing to better understand and protect this unusual species.
What is a Pyrenean desman?
The Pyrenean desman has a distinctive, almost comical look. Measuring around 11–16cm long, with a flattened tail of similar length, it has soft, velvety waterproof fur and large, webbed hind feet.
Its most striking feature is the long, highly flexible snout (reminiscent of an elephant's trunk), which it uses to search for prey underwater. Its small eyes and ears are further adaptations to a mostly aquatic lifestyle, with vision playing a minor role in its world.
Where does the Pyrenean desman live?
This species is highly specialised and restricted to clean, fast-flowing streams and rivers in mountainous regions. It requires clear, well-oxygenated water with abundant invertebrate life.
The desman builds burrows into steep, muddy riverbanks, with entrances just below the water’s surface. It avoids still water and is highly sensitive to pollution, damming and habitat disruption.
Range and distribution of the Pyrenean desman
The Pyrenean desman is endemic to parts of northern Spain, Portugal and small areas of south-western France. Its distribution is patchy, and populations are fragmented.
It prefers elevations between 400 and 2,500 metres, often within remote and rugged landscapes where human access is limited — which offers it some protection.
Pyrenean desman behaviour
Largely nocturnal and solitary, the Pyrenean desman is an expert swimmer. It uses its webbed feet and powerful tail to move through water in search of food.
It’s a stealthy forager, relying on its sensitive snout and whiskers to detect vibrations from prey hiding in gravel and silt.
It spends most of its time either foraging or hidden in its burrow, and very little is still known about its reproductive or social habits.
What does the Pyrenean desman eat?
The desman’s diet consists mainly of aquatic invertebrates, including insect larvae, worms, molluscs and small crustaceans. Occasionally, it will take tadpoles or small fish.
It forages by feeling along the stream bed, using its snout like a probe to detect and extract prey.
Pyrenean desman vs mole: what's the difference?
At first sight, the desman looks a bit like a chunky shrew. With a bodylength of 14cm, it’s about the same size as a mole (though that comparison doesn’t help much, given how rarely we glimpse moles), and the tail extends it by a further 16cm. The desman’s close affinities to ‘mole-kind’ (Talpidae) are further apparent with its dumpy body, lack of external ears, barely discernible eyes buried in grey-brown fur, and robust and powerful limbs.
The limbs are in reverse size-order to those of a mole and are just one of the adaptations to a life aquatic that start to make this animal stand out from the crowd. The rear legs are longer and more heavily muscled, equipped with clawed toes fringed with stiff hairs and with webbing in between. These are the desman’s main ‘thrusters’: powerful paddles that propel it through the water, while the long, slightly keeled tail makes for a stabilising rudder.
Why does the desman have such a long nose?
Slender, incredibly muscular and surprisingly flexible, the nose terminates at a slightly bifurcated tip and two prominent nostrils. All this gives the animal its alternative (and brilliant) colloquial name of trumpet rat.
That nose is the most peculiar thing to see in action. The desman catches prey on the stream bed – primarily aquatic insects, crustaceans, worms and small molluscs – and brings it to the surface to consume. Its nose is almost prehensile, bending and prodding in conjunction with the front limbs to manipulate a meal. Watching a desman dispatch and dismember a large stonefly nymph is quite something.
But there is much more to this ‘trompe’ than just being an extra limb. Look closely and you’ll see it bristling with hyper-sensitive, stiff whiskers known as vibrissae. Many are tiny, sandwiched between minuscule papillae that give the skin a distinctive texture when viewed under a microscope. These structures are Eimer’s organs – specialised touch receptors found only in moles. If you still doubt this animal’s kinship to its subterranean cousin, this should close the deal. A desman, though, takes things a step further: it has thousands more of these receptors on the tip of its snout, making it a super somatosensory organ that effectively replaces the rest of the animal’s face.
Sensitive to touch, vibration and smell, the snout does the job of eyes, ears and tastebuds, allowing the desman to find its way around underwater and locate prey from considerable distances. Evidence shows that desmans not only ‘feel’ their prey but smell it too, by rapidly blowing out and re-inhaling air bubbles four times a second while swimming. This underwater sniffing allows the transfer of scent particles from the water to the Jacobson’s organ – a highly sensitive collection of cells at the base of the nasal passage. A desman’s nose really is its secret weapon.
Conservation status
The Pyrenean desman is currently listed as Vulnerable by the IUCN. Threats include water pollution, habitat fragmentation, hydroelectric dams and climate change, which affects water levels and stream quality.
Conservation efforts focus on habitat restoration, water quality improvement, and better understanding population dynamics through monitoring.
What's that smell?
Desmans release a strong musky scent from glands near their tail. It’s used for marking territory, attracting mates, and (strangely) was once harvested for perfume.
The name desman comes from the Swedish desmanratta, which has roots in the word for musk or pleasant scent. Desmanratta translates as muskrat – referring not to the North American mammal but to the glands at the base of a desman’s tail, which emit a scent for communication and territory-marking.
How many species of desman are there?
There are two species of desman: the Pyrenean desman (Galemys pyrenaicus) and the Russian desman (Desmana moschata).
The Russian desman is larger, found in Eastern Europe and Russia, and prefers lowland rivers and lakes.
A living fossil
The Pyrenean desman is a living fossil, having remained relatively unchanged for millions of years. Its odd mix of features — mole, shrew and otter — dates back to prehistoric times.
Did you know?
- The desman can stay underwater for over two minutes while hunting.
- Its tail not only helps with swimming but also stores fat for lean times.
- Despite its small size, it has a large home range and actively defends it.
Main image: Pyrenean desman. Credit: Getty
More amazing animals from around the world
- Dire wolf 'de-extinction': here's everything you need to know
- Rescue mission: 17 rare mountain bongos airlifted halfway around the world – see inside the epic journey
- Massive eyes, exceedingly long intestines and a flying cloak – meet the almost unfathomable colugo
- Camera traps reveal formidable animal rampaging through rare monkey puzzle forests in Chile
