Grand polatouche
Glaucomys sabrinus
Mammifère
Écureuil nocturne des forêts de conifères qui plane d'un tronc à l'autre sur une membrane tendue du poignet à la cheville, en se dirigeant à l'aide d'une large queue aplatie. Son importance pour la forêt est surtout souterraine : il se nourrit abondamment de truffes, les fructifications des champignons mycorhiziens qui gainent les racines des conifères, et en disperse les spores dans ses crottes. C'est par lui que ces champignons atteignent un nouvel arbre, si bien que le lien avec les conifères est en réalité à trois.
Conservation
Largement répandu et non menacé dans la forêt boréale, mais les populations du sud des Appalaches sont un autre cas : ce sont des reliques isolées dans les forêts d'altitude d'épinettes et de sapins depuis la dernière glaciation, coupées de l'aire principale et suivies séparément comme sous-espèces propres. Ce qui les menace, c'est la perte et la fragmentation de cette étroite bande de conifères de montagne, non une pression sur l'espèce dans son ensemble.
Plantes du catalogue
Plantes abri · 7
Balsam fir forest is core northern flying squirrel range, and the species dens in cavities and in the dense witch-broom growths that fir broom rust (Melampsorella caryophyllacearum) induces on fir branches - a defect from a timber point of view and a nest site from the squirrel one. Marked plausible rather than documented because the denning association is reported for fir-spruce forest generally rather than as a published record on Abies balsamea specifically.
Dens in cavities in these forests and feeds heavily on truffles, the underground fruiting bodies of the mycorrhizal fungi that sheathe Douglas fir roots. It passes the spores in its droppings, so it helps carry the fungal partner the tree depends on to new ground.
Dens in cavities in these stands and glides between the trunks at night. Its truffle-heavy diet also disperses the spores of the mycorrhizal fungi hemlock roots depend on, so the tie runs through the soil as well as the canopy.
Dens in cavities and old woodpecker holes in these stands and glides between trees at night. Its main food is hypogeous truffles, so it disperses the spores of the mycorrhizal fungi that grand fir roots depend on - a relationship that runs underground rather than through the cones, and one reason old rot-hollowed firs are worth leaving standing.
The tightest wildlife tie on this species, and a conservation one. Northern flying squirrels feed heavily on truffles - the fruiting bodies of the mycorrhizal fungi sheathing conifer roots - and disperse the spores, so the relationship runs three ways between squirrel, fungus and tree. Two isolated southern subspecies depend on high-elevation red spruce and northern hardwood forest: the Carolina northern flying squirrel, federally listed endangered in 1985 and still listed, and the West Virginia northern flying squirrel, listed the same year and successfully DELISTED in 2013 after habitat recovery. Restoring red spruce is the stated mechanism in both cases, and more than 7,455 acres of West Virginia habitat were created, protected or restored in the five years after delisting.
Dens in cavities and witches-broom clumps in spruce-fir stands and glides between trees at night. Its relationship with the fir runs partly underground: it feeds heavily on truffles and disperses the spores of the mycorrhizal fungi that the fir roots depend on, so the tree and the squirrel are linked through the soil as much as through the branches.
Dens in cavities in these stands and glides between them at night. Its truffle diet disperses the spores of the mycorrhizal fungi on fir roots, a relationship that runs underground rather than through the cones.
Répartition
Forêts de conifères et forêts mixtes de l'Alaska et du Canada, vers le sud à travers les montagnes Rocheuses et la Sierra Nevada, autour des Grands Lacs et en Nouvelle-Angleterre, et le long des Appalaches. Depuis la séparation en 2017 du polatouche de Humboldt, de nombreuses autorités traitent les populations de la côte pacifique comme une espèce distincte ; cette fiche décrit donc le concept restreint postérieur à cette scission.
Sources et citations
Citer cette page
Utilisez cette citation pour la fiche faune Plotwright. Utilisez les fiches de sources ci-dessous pour explorer les références ayant alimenté sa taxonomie, sa répartition, sa conservation, ses plantes hôtes, son alimentation et son habitat.
Plotwright. (n.d.). Grand polatouche (Glaucomys sabrinus). Retrieved 2026, August 20, from https://plotwright.com/wildlife/northern-flying-squirrel
Sources utilisées pour cette fiche
Cette fiche est élaborée à partir des sources ci-dessous.
Animal Diversity Web: Glaucomys sabrinus
Species account for gliding, nocturnal habits, the hypogeous-fungi diet and spore dispersal, cavity nesting, and the isolated Appalachian populations.
GBIF: Glaucomys sabrinus
GBIF backbone key 2437331 is an exact accepted match in family Sciuridae. Note the backbone carries NO record for Glaucomys oregonensis, so GBIF occurrence data for this name still includes the Pacific coastal populations that the 2017 split moved to Humboldt’s flying squirrel.
iNaturalist: Glaucomys sabrinus
iNaturalist taxon 46266 is the active species record and DOES recognise the split, carrying Glaucomys oregonensis separately as taxon 553059. Its range data is therefore the narrower concept, and differs from GBIF on the Pacific coast.
Wikipedia: Northern flying squirrel
Corroborating reference for the truffle diet and spore dispersal, the 2017 species split, and the relict Appalachian subspecies.