No one really knows how many desmans, these small “amphibious” mammals – curious crosses between the mole, the shrew and the rat – shelter the Pyrenees. You have to be quite lucky to meet this cute “trumpet rat” on the banks of a torrent. And the odds get even smaller over the years. In his last
report, the International Union for the Conservation of Nature (IUCN), which publishes its alarming catalog of endangered species each year, estimates that the population of desmans of the Pyrenees, also present in the north-west of the Iberian Peninsula, “has fallen by half during the last decade ”. Despite a conservation program launched in 2014, the small animal previously classified in the “vulnerable” category has jumped to that of species officially considered “endangered”.
This news does not really surprise the four project managers of the Conservatory of Natural Areas of Occitania who have been tracking the discreet trumpet rat for several years. “There are some well-known areas where we used to find them and where there is no longer any trace of their presence,” says Melody Lim. This summer, on the banks of the Salat in Ariège, where the desmans usually select natural crevices for “shelter” – for lack of being able to dig themselves with their tiny clawed front paws – the team did not find any index. No hairs, not even the recognizable “strings of droppings” of the mammal fond of insect larvae and crustaceans.
Dams but also otters … and cats
The IUCN attributes the decline of desman “to the impact of the development of waterways”, citing “hydroelectric dams” and withdrawals related to agricultural irrigation or “the production of artificial snow for ski resorts. “. “Let’s say it’s a combination of factors that gradually loses the habitat favorable to desman,” adds Melody Lim. The findings of the CEN team and the multiple partners involved in the preservation of animals throughout the massif, autopsies in particular, also show that there is no shortage of predators: otters, minks, even domestic dogs or cats, for whom a rat is a rat, trumpet or not.
The new classification of the desman is worrying but it can also have advantages. “It will make it possible to release credits while a new national action plan is initiated until 2030”, hopes Melody Lim, convinced that there is still “so much to discover about this little-known species”. In recent years, thanks to radio chips, slightly glued and therefore quickly lost, CEN has been able to follow three desmans. The tracing revealed that these “platypus” of the Pyrenees, known to be solitary, “sometimes share their home ranges”. Without going as far as the roommate, it even happens that they pass on the lease of their lodging.