Relict Marsupial (Dromiciops) from Southern South American Temperate Rainforests: Threatened by Habitat Loss, Fragmentation, and Transformation

Among South American marsupials, Dromiciops gliroides (Thomas 1894), a relict arboreal marsupial closely related to Australian marsupials, is the only extant living species of the order Microbiotheria. This species inhabits the Patagonian temperate rainforests acting as the principal seed disperser agent. Despite its evolutionary uniqueness and ecological significance, D. gliroides is threatened by habitat loss, fragmentation, and degradation. The rapid deforestation of recent decades has dramatically reduced the amount of suitable habitat for this species, impacting its occurrence, abundance, and activity patterns. Also, habitat disturbance has altered its ecological interactions, altering plant reproduction, spatial arrangement, and gene flow. Those alterations have important consequences on plant communities, which formed novel ecosystems in some cases. This generalist marsupial seems to be more resilient to disturbance than initially thought, but the long-term consequences are yet to be seen. Altogether with habitat disturbance, climate change also imposes a significant threat on D. gliroides. While severe drought events reduce fruit production, warmer winters may have dramatic consequences at a physiological level (hampering its hibernation patterns). These dramatic changes in the ecological scenario of D. gliroides may be compromising its long-term persistence.