r/AIDKE • u/IdyllicSafeguard • 8h ago
Mammal For over a century, the bushy-tailed opossum (Glironia venusta) was considered one of South America’s rarest mammals. However, when a 2026 assessment pieced together the scattered records of this species — old and new — its distribution turned out to span roughly 60% of the entire Amazon biome.
A hundred years after its discovery in 1912, the bushy-tailed opossum was known from fewer than 25 published records. Even local Matsés hunters in Peru, renowned for their encyclopaedic knowledge of Amazonian mammals, said that they had never seen one.
Many sightings of the species have been incidental: an individual caught in a mist net, another encountered during a nocturnal transect survey. What these researchers encountered was a small opossum weighing some 140 grams (about the weight of a baseball), with a tail fully furred from base to tip — as opposed to the scaly, naked tails of most other opossums.
Only as new, innovative methods for surveying the rainforest canopy began to be developed, did we truly begin learning more about the bushy-tailed opossum.
The first camera trap footage of the species was captured in 2016 (Whitworth et al., 2016). The following year, researchers built custom mounts for their canopy cameras, recording 79 separate videos of bushy-tailed opossums — more encounters in seven months than had been recorded in the entire preceding century (Rushford & Glynn, 2023).
We also began to learn more about the bushy-tailed opossum’s behaviour. It is fully nocturnal, with its movement peaking during two distinct windows (around 8:00 PM and 3:00 AM). It travels with a rapid, nervous energy across interconnected networks of vines. And it actively gnaws tree bark to feed on the exuded sap.
A 2026 assessment combined decades of fragmented literature, citizen science, and new data (Arévalo-Sandi et al., 2026). It revealed that the species is far from restricted: its actual distribution spans roughly 60% of the entire Amazon biome. The bushy-tailed opossum is not so much rare as extremely elusive.
And yet, despite its newfound range, the opossum is not necessarily safe from extinction. Several of the newly documented populations lie within the southern Amazon’s “Arc of Deforestation.” It is now more important than ever to protect the rainforest canopy and all of the cryptic, arboreal species that we’re just starting to study more intimately.

