Pyrenean desman

General anatomy ). The Pyrenean desman measures approximately in total length, more than half of which is accounted for by the tail, and has a body mass of 50 to . There is no pronounced sexual dimorphism; females are on average slightly larger than males. Reliable sex determination generally requires close examination of the external genitalia. The species has webbed hind feet, a relatively uncommon adaptation among insectivorous mammals, which is one of the characteristics supporting its placement in a monotypic genus. The genus Galemys includes only this single species. Comparable adaptations are otherwise found only in Limnogale, the Ruwenzori otter shrew, and the elegant water shrew. In other respects, the morphology of the Pyrenean desman combines features found in several more familiar mammals: • from the brown rat, it shares robust hindquarters, well-developed thighs, and a long, thick tail that facilitates locomotion in aquatic environments; • from moles, it has powerful, clawed forelimbs adapted for digging burrows used for shelter and rearing young, as well as a snout with a highly developed tactile capacity; • from the common shrew, it shows a prehensile trunk and prominent vibrissae, which are used to detect prey larvae and to orient within its surroundings. The dentition comprises , arranged according to the dental formula 3.1.4.3 in both the upper and lower jaws. This complete dentition corresponds to that observed in European moles. The two anterior upper incisors are particularly developed. The first premolar, considered supernumerary, is interpreted as a deciduous tooth that has become permanent. Adaptations On land, the Pyrenean desman has a rounded, stocky body. The fur is grey-brown, with silvery reflections on the underside and a tawny coloration in the pectoral region. The hairs are arranged in small tufts that can give a scaly appearance. Regular grooming with an oily secretion produced by abdominal glands ensures a high degree of waterproofing. The fur is therefore well adapted to an aquatic lifestyle and underwater diving. It is composed of two layers: a dense, silky underfur that remains dry, and an outer layer of long, flattened guard hairs of varying length. When submerged, this structure forms a smooth surface that retains body heat by trapping a layer of insulating air. This trapped air also increases buoyancy, in accordance with Archimedes' principle, requiring the animal to remain in constant motion underwater to avoid surfacing, which increases energy expenditure and partially offsets the insulating effect. In water, which constitutes its primary habitat, the body assumes a streamlined profile. The forelimbs are held close to the body, while the robust, webbed hind feet are spread at an angle of about 45 degrees and function as paddles; they are equipped with sharp claws that facilitate gripping onto rocks. During dives, which typically last around twenty seconds, valves close the nostrils. The Pyrenean desman is an agile and powerful swimmer, capable of rapid movement in water and of swimming upstream, including at the surface. The eyes are visible but partly concealed by the fur. As in most members of the family Talpidae, vision is poorly developed, and the animal is able to distinguish little more than variations in light intensity. The ears lack external pinnae and are entirely hidden beneath the fur, consisting only of a circular opening measuring approximately in diameter. The tail extends from the posterior of the body and is broad at the base, gradually tapering toward the tip, which bears a small tuft of white hairs. At the base of the tail and on the ventral surface are two musk glands, whose swelling is readily apparent. Trunk At the anterior end of the body is the desman's most distinctive structure: an enlarged proboscis that is hairy at the base and otherwise bare, measuring about in length and accounting for roughly one quarter of the animal's body length. This proboscis is flexible and prehensile, and divides distally into two lobes that contain the nostrils. As in the elephant, it results from the evolutionary fusion of the nose and the upper lip. The proboscis constitutes the desman's principal sensory organ and, like that of moles, is among the most highly specialized tactile structures in mammals. It is used to detect prey underwater and to explore both aquatic and terrestrial environments. Sensory perception is mediated, first, by vibrissae at the base of the proboscis, which detect nearby and distant vibrations and movements. Second, the terminal lobes are covered with hundreds of thousands of Eimer's organs, whose high sensitivity enables the detection of prey within stream substrates. In addition, the vomeronasal organ (Jacobson's organ) is thought to contribute to the chemical detection of prey. This organ is located at the entrance of the nasal cavities, which communicate with the oral cavity via the palate. Its development is associated with a highly sensitive sense of smell, allowing the detection of larvae at distances of up to underwater. The vomeronasal organ is the sole olfactory system in fish and amphibians and is also present during embryonic development in mammals, including humans; in most mammals, its function is reduced after birth as olfactory perception becomes primarily mediated by the nasal conchae located deeper within the nasal cavities. File:Galemys_pyrenaicus_02_crop-by-dpc.jpg|alt=Close-up of an animal's trunk with long perpendicular hairs at the base, the tip bare and ending in two bulbous nostrils surrounded by papillae.|Detail of the trunk with sensory organs such as vibrissae and papillae housing Eimer's organs. File:Gray51.png|alt=Coloured diagram showing different organs.|Section of the nasal cavity of a human embryo. The vomeronasal organ (Jacobson's organ) is identified on the right. This organ is vestigial in humans but highly developed in some species like the desman. File:Taxidermised_Galemys_pyrenaicus_in_MNHN_-_close_up.JPG|alt=Close-up photograph of the front of the body of an animal with a trunk, long hairs, and small legs with strong claws.|Vibrissae at the base of the trunk and clawed forelegs are clearly visible. Taxidermy specimen, MNHN. Cognitive abilities Scientific studies indicate that the Pyrenean desman exhibits well-developed spatial memory and orientation abilities relative to other mammals of comparable size. Individuals are able to retain information about the geometry of frequently used paths, as well as the olfactory and gustatory characteristics of their home range. Post-mortem examinations have shown that the cerebellum, a brain region involved in spatial coordination and orientation, is proportionally well developed in this species when compared with many other mammals. In particular, the cerebellum of the Pyrenean desman is larger than that of the mole or the Russian desman and, in proportional terms, is approached only by that of cetaceans. Experimental observations further suggest that the desman is capable of discriminating, through tactile perception, between geometric forms, surface textures, and degrees of granularity. It can also recognize familiar shapes when they are rotated or presented from different orientations. These abilities imply the integration of tactile sensitivity with higher-order cognitive functions, including memory, three-dimensional shape processing, and spatial orientation. Feces The feces of the Pyrenean desman are distinctive in appearance. They consist of small, twisted cylindrical pellets measuring approximately in length, with an oily texture and a colour ranging from dark green to black. They also emit a musky odour that is generally not readily identifiable by the human sense of smell. Feces are most commonly deposited on rocks above the waterline. They act as a substrate for secretions from the musk glands and are thought to play a role in territorial marking and in the exchange of information between individuals. == Habitat and distribution ==

Geographic range The Pyrenean desman is an endemic species of mountainous regions of the Pyrenees, the Cantabrian Mountains, and the Iberian Sistema Central. It occurs primarily along specific rivers and their tributaries (listed from north to south and from west to east): • France: Nivelle, Nive, Gave d'Aspe, Gave d'Ossau, Adour, Neste, Pique, Garonne, Hers-Vif, Salat, Arize, Ariège, Aude, , Agly, Têt, and Tech; • Spain: Bidasoa, Leitzaran, Deba, , Lea, , Oka, Auritz, Irati, Aragon, Gállego, sierra de Guara, Ara, Cinca, Noguera Ribagorçana, Noguera Pallaresa, Segre, Ter, Oviedo, Pisuerga, Xallas, Tambre, Lérez, , Sil, Tâmega, Arandilla, Duero; • Portugal: Minho, , Lima, Neiva, Cávado River, Ave, , Douro, Vouga, Mondego, Zêzere. Many of these rivers are separated by continental divides or belong to distinct and non-contiguous drainage basins; as a result, the species' distribution is highly fragmented. At a broad scale, the current range is considered a remnant of post-glacial expansion into newly available habitats, facilitated by terrestrial corridors and possibly a denser river network during the Holocene. At a finer scale, however, movements between neighbouring drainage basins may have occurred more recently. Habitat type ). The Pyrenean desman typically inhabits oligotrophic streams at low, medium, and high elevations, characterised by clear, nutrient-poor water. These watercourses have a permanent flow and a sufficiently strong current. The species generally avoids intermittent streams and poorly oxygenated stagnant waters, but it may also occupy high-altitude lakes, both natural and artificial. The Pyrenean desman is a proficient swimmer, suited to its aquatic habitat, although its claws also allow it to be good at climbing. Rivers inhabited by the desman are usually free from significant anthropogenic pollution. Its prey consists largely of aquatic larvae that are highly sensitive to changes in acidity, temperature, oxygen levels, and water turbidity. For this reason, the presence of the desman is considered an indicator of high water quality, and the species is widely regarded as a reliable bioindicator. Altitudinal limits The Pyrenean desman shows some tolerance to a wide altitudinal range, although it is most commonly associated with mid- and high-mountain environments. In France, the species has been recorded at above sea level near Saint-Pée-sur-Nivelle in the Pyrénées-Atlantiques. This record is considered exceptional; in other French Pyrenean departments where systematic surveys have been conducted (Ariège, Aude, Pyrénées-Orientales), the species is generally found from upward. On the Spanish side of the range, where precipitation levels are lower, the minimum recorded altitude is approximately . Using the same density estimates, population size was calculated at approximately one individual per square kilometre. When extrapolated to the French Pyrenees as a whole, this corresponds to an estimated population of fewer than in France. Studies conducted in the 2010s reported higher densities, estimated at per linear kilometre in France and per linear kilometre in Spain. In favourable local conditions, densities may be higher still. Some authors have suggested that population size at this level could allow reproductive output to exceed the species' renewal threshold, potentially enabling population growth. However, elevated mortality rates appear to offset recruitment, resulting in overall population stability. A reversal of this balance could increase the risk of population decline. == Life cycle ==

Territory and lifestyle ). The Pyrenean desman occupies a defined home range, typically alone or as a pair, although non-territorial or dispersing individuals have also been recorded. Home-range size varies according to local conditions, including food availability, population density, and the sex of the individual. On average, territories extend over several hundred metres of river. Females generally occupy about of linear watercourse, males about , and pairs sharing the same sector up to . Within paired territories, individuals usually remain spatially segregated, using separate resting burrows while occupying the same stretch of river. Some studies indicate that females tend to occupy the central part of the territory, with males more frequently using peripheral areas. Both males and females scent mark. They have been thought to be aggressive towards other adult members of the species. However, more recent research suggests they are non-territorial and that adults have overlapping home ranges. Juvenile dispersal and seasonal movements by adults have been suggested, although their extent and frequency remain uncertain. Recent research has documented social interactions and suggests the existence of a more flexible spatial organisation than previously assumed. Home ranges of several individuals, of the same or different sex, may overlap, and encounters do not necessarily result in aggressive behaviour. Individuals typically use two to three resting sites, and occasionally up to seven, some of which may be shared with conspecifics. The desman regularly patrols its territory and appears to detect environmental changes. It uses a behaviour described as "drumming", striking the water surface with its forepaws to generate low-frequency waves whose reflections may provide information about its surroundings. This mechanism has been compared to forms of echolocation observed in other aquatic mammals. Individuals have also been observed releasing small air bubbles during underwater movement, which may limit dive duration. The function of this behaviour is not fully understood; hypotheses include a sensory role similar to echolocation or a link to chemical perception via the vomeronasal organ. Parturition has not been observed directly but is presumed to take place in underground burrows. Litter size does not exceed five individuals and more commonly comprises three to four. Females possess eight teats: two pectoral, two abdominal, and four inguinal. Sexual maturity is reported to be reached within a few weeks. Lifespan Males and females are reported to live for approximately three to four years. Marked individuals have been recaptured up to three years after their initial capture, and analyses of dentition in 87 specimens have not identified any individuals older than four years. Breeding in captivity has not been documented. Captive individuals may die if husbandry conditions do not adequately meet the species' ecological and physiological requirements. Diet Foraging Foraging on the stream bed constitutes the desman's principal activity. Prey is located using highly developed tactile and olfactory senses, including liquid-phase olfaction mediated by the vomeronasal organ and, in particular, tactile perception via vibrissae and Eimer's organs on the trunk. These sensory systems enable prey detection either indirectly, through movement or odour, or by direct contact. Precise localisation of prey in water has been reported at distances of up to , while the presence of potential prey may be perceived over several tens of centimetres. The desman is unable to pursue actively swimming prey or items carried rapidly by the current. Its diet therefore consists mainly of benthic larvae found in slower-flowing sections of streams, and more rarely of insects encountered near the water surface. Food The desman has a high metabolic rate and must consume approximately one-third to one-half of its body mass daily (). During mid-winter, when water temperatures are lowest, daily intake may reach its entire body mass (). The mountain winter period (January–April) coincides with both the reproductive phase and peak prey availability. Analyses of stomach contents, faeces, and observations of captive individuals indicate that the diet consists primarily of benthic invertebrate larvae belonging to three insect orders: mayflies, stoneflies, and caddisflies. Early morphological studies characterised the species as a specialised predator. Molecular analyses of faeces conducted in the 2010s refined this assessment, showing that these three orders account for about 80% of prey items but represent only one-third of the identified prey species. Additional prey include dipteran larvae and crustaceans such as freshwater shrimp. A broad range of other taxa is consumed opportunistically, including beetles, lacewings, true bugs, moths, dragonflies, myriapods, arachnids, newts, snails, and occasionally fish. File:Ephemera_vulgata.JPG|Larva of mayfly File:SteinfliegenLarve2.JPG|Larva of stonefly File:Koecherfliegenlarven.jpg|Larvae of caddisfly Strictly terrestrial prey, such as spiders, grasshoppers, and earthworms, account for around 10% of prey items and more than one-third of identified species. These prey are less frequent outside summer and may result from active foraging on land, incidental encounters, or accidental immersion. In contrast to the larger Russian desman, the Pyrenean desman has only rarely been observed consuming fish or amphibians, a finding corroborated by molecular analyses of faecal samples. Caddisfly larvae, which are energy-rich, appear to be preferentially selected and are captured during dives lasting approximately . Their relatively large size facilitates capture and provides a high energetic return relative to effort. Small prey are swallowed underwater, whereas larger larvae are typically consumed out of the water on banks or rocks, with the animal sitting on its hind legs and manipulating prey using its prehensile trunk. Dietary diversification has been interpreted as a response to changes in aquatic communities associated with environmental stressors such as pollution or seasonal fluctuations in climate and water flow. Earlier interpretations attributed the species' sensitivity primarily to anthropogenic pollution; however, subsequent studies indicate that the aquatic larvae on which it depends are themselves highly sensitive to changes in water clarity, acidity, and oxygenation. Monitoring physico-chemical parameters of the desman's aquatic habitat, including indicators such as biochemical oxygen demand, is therefore considered important. Predation The desman is preyed upon mainly by the Eurasian otter. Other documented predators include the common buzzard, northern pike, stoat, tawny owl, white stork, grey heron, and black-crowned night heron. Predation by the barn owl has been reported only rarely. The invasive American mink, which is widespread in the Cantabrian Mountains, represents an additional predation pressure in Spain, where numerous predation events have been recorded. Domestic dogs and cats have also been identified as potential predators. Parasitism Most aquatic invertebrates consumed by the desman, at both larval and adult stages, are capable of acting as intermediate hosts for parasitic worms. The most frequently reported trematode is Omphalometra flexuosa, which is also found in the European mole; its encysted larval stage develops in the freshwater shrimp Gammarus pulex. Maritrema pyrenaica is another trematode shared with the Eurasian water shrew; its first intermediate host is the snail Bythinella reyniesii, with subsequent larval encystment occurring in the shrimp Echinogammarus berilloni. The trematode Mathovius galemydis and the nematode Paracuaria hispanica are known only from Iberian desmans and use aquatic arthropods or crustaceans as intermediate hosts. The external mite Eadiea longisetosa, also found on the Russian desman, inhabits the desman's fur. The parasite fauna of the desman is likely incomplete. For instance, the trematode Pseudocephalotrema pyrenaica is common in habitats typically occupied by the desman and may parasitise it, although this association has not yet been formally demonstrated. == Taxonomy ==

). The type locality is in France, described as "in the mountains near Tarbes", in the Hautes-Pyrénées department. The holotype—the preserved specimen on which the original species description was based—is housed at the Muséum national d'histoire naturelle in Paris. In 1829, the species was reassigned to the genus Galemys by the German naturalist Johann Jakob Kaup, who designated it as the type species of the genus. Etymology The generic name Galemys is derived from the Ancient Greek (galễ, meaning "weasel") and (mûs, meaning "mouse"). The term "desman" originates from the Swedish desman ("musk"), a diminutive of desmanrätte ("muskrat"). This word ultimately derives from Middle Low German Desem and Medieval Latin bisamum, both of which refer to musk. Synonymy Galemys pyrenaicus has the following synonyms: • Mygale pyreneica Geoffroy Saint-Hilaire, 1811 (protonym) • Myogalea pyrenaica (Geoffroy Saint-Hilaire, 1811) • Desmana pyrenaica (Geoffroy Saint-Hilaire, 1811) Vernacular names In French, the taxon bears the standardised common names "Desman des Pyrénées" and "Desman ibérique", as well as the vernacular names "Rat-trompette" and, more rarely, "Taupe des Pyrénées". Phylogeny The Pyrenean desman is an insectivorous mammal belonging to the family Talpidae, subfamily Desmaninae, and is the sole extant species in the genus Galemys. Its closest living relative, and the only other surviving desmanine, is the larger Russian desman (Desmana moschata), which occurs in the drainage basins of the Volga, Ural, and Don rivers. The species has a diploid chromosome number of 42. Karyological studies indicate affinities with the genus Talpa, supporting its placement within the order Eulipotyphla and the family Talpidae. Molecular analyses based on mitochondrial DNA and nuclear DNA have produced less consistent results regarding the position of desmans within the family. Some studies place them approximately equidistant from the tribes Condylurini (which includes the star-nosed mole) and Talpini (which includes the European mole and Spanish mole), while others suggest a closer relationship with the Talpini. These analyses consistently support a close evolutionary relationship between the Pyrenean and Russian desmans and confirm their assignment to separate, monophyletic genera. Subspecies Two subspecies of the Pyrenean desman are recognised: • Galemys pyrenaicus pyrenaicus (Geoffroy Saint-Hilaire, 1811) • Galemys pyrenaicus rufulus (Graells, 1897) The subspecies rufulus was described in 1897 by the Spanish naturalist Mariano de la Paz Graells as the variety Myogalea pyrenaica var. rufula, based on specimens collected in the Valsaín Valley in the Sierra de Guadarrama of central Spain. Graells distinguished this taxon primarily by its yellowish fur, described as giving a golden appearance underwater, and by the presence of bright yellow skin and claws on both the fore and hind feet; by contrast, the nominate form was characterised by browner fur with a silvery appearance underwater and brown feet. By the 2000s, the two subspecies were recognised as being geographically well separated: pyrenaicus occurs in the Pyrenees on both the French and Spanish sides, whereas rufulus is found in other mountain ranges of northwestern Iberia. Differences in coloration are no longer regarded as diagnostically reliable, and the subspecies are now distinguished mainly on the basis of cranial morphometric characters. == Paleontology ==

Fossil evidence documents the presence of several desmanine species across Europe, ranging from the Urals to the Atlantic coast, from the middle Miocene approximately 15 million years ago until the end of that epoch around 5.3 million years ago. The two extant desman species are therefore regarded as remnants of formerly more widespread populations that became fragmented during successive glaciations. The Russian desman is morphologically and in overall size closer to early desmanines than the Pyrenean desman, whose evolutionary pathway toward adaptation to mountain environments and subsequent speciation remains poorly understood. Molecular analyses estimate the divergence between the two species, and thus between the two genera, at approximately 10 million years ago. The genus Galemys is known from the late Pliocene (about 2.6 million years ago), after which its distribution progressively contracted from central and western Europe to its southwestern limit, the Iberian Peninsula. This region, whose mountain areas were not covered by ice during the last glaciations, is considered to have acted as a refugium. This pattern suggests that Galemys was already specialised for fast-flowing mountain waters and that the Pyrenean desman represents a relict species. The evolutionary divergence between the subfamilies Talpinae and Desmaninae is poorly documented in the fossil record. Molecular data indicate that this split occurred around 37 million years ago, near the transition from the middle to the late Eocene. == Anthropogenic threats ==

at Saint-Girons in Ariège. The Pyrenean desman is a species highly specialised for life in mountain streams, a habitat that is declining as mountainous areas undergo increasing human modification. Several pressures associated with urban and technological expansion in the early 21st century pose risks to the species. These include water impoundments that cause abrupt changes in river flow and temperature; weirs and other barriers that fragment river systems; artificial bank reinforcement and wetland drainage that result in direct habitat loss; and various forms of pollution that disrupt aquatic ecosystems. Alterations in current velocity, water depth, acidity, and oxygen availability adversely affect the invertebrate larvae that constitute the desman's primary food source. The adequacy of this minimum flow remains debated among Portuguese, Spanish, and French researchers, as very low summer discharges are associated with high mortality in many aquatic species. To evaluate the potential impacts of dams and other river infrastructures, biotic water analyses were conducted upstream and downstream of the Lac de Bious-Artigues dam in the Pyrénées-Atlantiques and upstream and downstream of the highly polluting paper mill at Eycheil on the Salat in Ariège. These studies detected no significant differences in water quality between upstream and downstream sites at the dam. On this basis, impoundments are not considered to pose an inherent threat to the desman's food resources. Bank reinforcement with riprap A study published in 1998 in the journal of the Pyrenees National Park examined changes in desman populations before and after riprap reinforcement of the banks of the Gave d'Aspe in the Aspe Valley. The works substantially reduced the availability of resting sites: of 25 sites known to have been occupied prior to bank modification, only six remained occupied after 1998. The desman relies on burrows excavated by other animals or on natural cavities for shelter. Since the 2000s, extensive riverbank reinforcement has been undertaken in many Pyrenean municipalities, primarily to protect infrastructure from flooding. As a mitigation measure, artificial wooden burrows lined with natural moss and dead leaves have been tested since the 2010s on streams with limited human disturbance, with the aim of providing alternative resting sites. Water intakes Accidental mortality of desmans has been documented at industrial, agricultural, and private water intakes. Individuals may enter feeder canals and become trapped in small-diameter pipes or against protective grilles at high-flow intakes. Water pollution Physico-chemical water pollution can disrupt mountain stream ecosystems. Changes in temperature, turbidity, acidity, or oxygenation may lead to the decline or disappearance of insect larvae that constitute the desman's primary food resource. Fishing and fish farming , French Basque Country. Until the 2000s, some anglers and fish farmers killed desmans under the belief that they preyed on fish. This perception was influenced by folklore, limited knowledge of the species' ecology, and inaccurate media reports in the 1980s and 1990s, including photographs of captive desmans fed exclusively on fish. Awareness-raising initiatives conducted in the 2010s among the general public, anglers, and fish farmers have contributed to improving perceptions of the species. The promotion of best practices, such as the collection of discarded fishing line, aims to reduce accidental mortality through drowning or strangulation. Tourism As desman activity is primarily nocturnal, it is generally little affected by tourist presence. However, certain recreational water activities that involve trampling stream beds, particularly canyoning, can severely degrade the benthic fauna on which the species depends, resulting in indirect impacts. Some studies anticipate local extirpation in heavily frequented areas, such as the Sierra de Guara in the Spanish Pyrenees. Climate change Modelling of the future distribution of the Pyrenean desman under climate scenarios for 2070–2099 indicates potential impacts associated with climate change. Average summer temperature and water balance are identified as the principal factors driving projected range contractions. Under the most severe scenarios, the species is predicted to disappear from the Iberian Sistema Central and northern Portugal, persisting only in high-altitude areas of the remaining massifs, including the Cantabrian Mountains and the Pyrenees. Assisted migration has been proposed as a possible long-term conservation option. == Conservation ==

Population status The desman population was considered to have stabilised during the 1980s; however, assessments conducted in the 2020s indicate a renewed decline. In 2021, the International Union for Conservation of Nature (IUCN) reclassified the species from "Vulnerable" to "Endangered", citing a substantial and ongoing population decrease documented over several years. The IUCN assessment reports an estimated decline of nearly 50% across the species' entire range since 2011. On the French side of the Pyrenees, the desman has disappeared from approximately 60% of the watercourses it occupied since 2000. The most pronounced declines have occurred in the western part of the range, particularly at lower elevations, whereas populations in the eastern Pyrenees appear more stable across altitudinal gradients. Population densities are also higher in the east, reaching up to 10 individuals per km² in the Aude basin. In 2017, the species' status on the French Red List of Mammals was consequently revised from "Near Threatened" to "Vulnerable". In Spain, the desman is listed as "Vulnerable" in the Atlas y libro rojo de los mamíferos terrestres de España (Red List of Mammals of Spain) and as "Critically Endangered" in the Sistema Central since 2007. In Portugal, the species has been classified as "Vulnerable" since 2005, and in Andorra as "Critically Endangered" since 2013. France The Pyrenean desman has been subject to strict legal protection in France since the ministerial decree of concerning protected mammals throughout the national territory. Its habitat is also protected under Article L.411-1 of the and by the ministerial decree of April 23, 2007. The species is listed in Annex II of the Bern Convention and in Annexes II and IV of the Habitats Directive Fauna-Flora 97/62/EEC. As a result, it is prohibited to destroy, mutilate, capture, or intentionally disturb individuals, as well as to destroy or degrade their habitat. The transport, possession, sale, or purchase of individuals, whether alive or dead, is also prohibited. is part of the desman's range. From the mid-2000s onward, a marked increase in scientific research on the desman was observed, leading to improved knowledge of the species and contributing to the development of conservation programmes. Research and conservation activities have been carried out primarily by university laboratories, with additional involvement from private consultancies and public bodies at local and regional levels. Funding and coordination have been provided by the Ministry of Ecology, the Fundación Biodiversidad, and the European Union. Two LIFE projects have been implemented in Spain. The LIFE+ "Margal Ulla" project was conducted from 2010 to 2015 and focused on the restoration of desman populations along the Ulla River in Galicia. The broader LIFE+ "Desmania" project, coordinated by the Fundación Biodiversidad, ran from 2012 to 2018 across 33 special areas of conservation for the species. Its objectives included scientific research on the desman (including biology and predation), population protection, habitat restoration, and public awareness activities. A central component of the LIFE+ projects involved the restoration of riparian woodlands. These actions have been associated with increases in benthic invertebrate populations that constitute the desman's food base, as well as benefits for ichthyofauna. Such measures may also support recreational activities, including sport fishing. Additional reported effects include improvements in water balance and water quality in the restored watercourses. Portugal A LIFE project entitled "" was carried out from 1994 to 1997 by the Nature Conservation Institute (ICN). The scientific results of this programme contributed to the preparation of a reference document for species conservation and habitat protection. Its recommendations were subsequently incorporated into the sectoral plan for the Natura 2000 network and transposed into Portuguese legislation. Since the mid-2000s, further scientific studies have refined knowledge of the species, particularly with regard to its geographic distribution and the effects of hydroelectric dams. In 2014, a report by the Institute for Nature Conservation and Biodiversity assessed the desman's conservation status in Portugal as unfavourable and identified it as a priority species. The report also identified an emerging threat linked to the spread of invasive plant species, including silver wattle and tree of heaven. In the same year, an action plan was initiated with the establishment of a monitoring network for the species in northern Portugal, with the aim of limiting population decline and habitat loss. The plan also set out several priority measures, including the ecological rehabilitation of dams and artificial reservoirs within the species' range, improvements in water quality, particularly through restrictions on agrochemical use near watercourses, and systematic waste collection along riverbanks. As an umbrella species, conservation actions targeting the desman are expected to benefit a broader range of aquatic biodiversity. Andorra Scientific studies have been carried out since 2002 under the responsibility of the Environment Department of the Andorran government, notably to document and map the species' distribution within the principality. A 2018 study comparing desman populations over two survey periods, 2000–2003 and 2013–2017, reported a decline of approximately 70% in Andorra and 43% in neighbouring Catalonia. The decline was attributed to several factors, primarily associated with land-use change and urban development, including increased water abstraction, construction activities near riverbeds, modifications in hydroelectric dam management, and episodes of severe flooding. No clear relationship with climate change effects was identified. In 2019, the Andorran government considered draft legislation to establish a restoration plan for threatened species, including the desman, and to integrate such species more systematically into environmental impact assessment procedures. == Human relations ==

History Although it is widespread in the Pyrenees, a mountain range inhabited by humans for centuries, the Pyrenean desman has remained poorly known and was long associated with unsubstantiated beliefs. Accounts collected in the late 19th and early 20th centuries from Pyrenean rural communities report claims that the desman hunts trout and feeds on fresh fish. Other testimonies state that, in summer, desmans could be observed sleeping in the shade of haystacks in open fields. Such accounts are generally regarded as elements of local folklore rather than information based on verified observations. Proposed explanations include confusion with other small rodents or semi-aquatic mammals that are more frequently encountered, as well as a tendency to label unfamiliar species as pests in order to justify their removal. The near absence of the desman from Pyrenean toponymy, in contrast to other widespread species such as the brown bear or the chamois, has likewise been interpreted as evidence of its limited recognition by local populations. Until the 1990s, anglers commonly but incorrectly accused the species of preying on trout and other fish valued for consumption. These perceptions stemmed from limited knowledge of the species and its diet, as well as from inaccurate articles in popular natural history publications, including photographs of captive desmans that had been fed fish. Scientific knowledge The Pyrenean desman remained largely unknown to scientists until the early 19th century, when it was formally described and classified by Étienne Geoffroy Saint-Hilaire on the basis of several dead specimens. Subsequent research was limited. Studies by Eugène Trutat in 1891 and by Puisségur in the 1930s focused mainly on the anatomy of a small number of captured individuals, as the species proved difficult to observe in the wild and could not be successfully bred in captivity. In the 1950s, Peyre managed to keep desmans alive in captivity without achieving reproduction and proposed interpretations of their behaviour and diet that were later shown to be incomplete or inaccurate. At that time, observations were almost exclusively based on captive animals, and the species' life cycle in its natural environment remained poorly understood. Comprehensive scientific studies in natural settings began only in the 1980s, addressing the species' distribution, habitat, and diet, which had previously been the subject of speculation. In the 21st century, significant gaps in knowledge persist. For example, extensive LIFE+ research conducted between 2015 and 2020 demonstrated that many individuals exhibit nomadic behaviour, whereas the species had previously been considered predominantly sedentary and territorial. Estimating population size therefore continues to present methodological challenges. In culture . In the 21st century, the Pyrenean desman remains little known to the general public. Since the 2000s, however, its visibility in Pyrenean regions has increased, largely as a result of public awareness initiatives associated with national action plans and LIFE+ programmes aimed at residents and tourists. Numerous educational activities have been developed, particularly for schoolchildren, using the species as a tool for environmental education and species conservation. The desman has increasingly been presented as an emblematic species of the Pyrenees, alongside animals such as the brown bear and the chamois. In this context, it is used as a flagship species to promote the protection of mountain biodiversity, notably through travelling exhibitions such as the "Desman caravan", organised since 2015, and the "Piribus", which has toured the French and Spanish slopes since 2019. Since 2013, a character named Joan Desman has served as the mascot of the in the Pyrénées-Orientales. The Béarn magazine PAG has also adopted the species as its mascot. In addition, the Pyrenean desman features as the main character in several comic books. A statue representing the species has been installed at the entrance to the tourist site of Étang de Lers, in Ariège. In May 2018, the Pyrenean desman became the 8,000th animal photographed for the Photo Ark project by National Geographic. == See also ==