Climbing rats superficially resemble large specimens of the black rat. However, they are much more distinct, having separated from most other rodents about 24 million years ago. Known only from 10 specimens recorded at the type locality in Chiapas (extreme southern Mexico), it has not been collected in at least 40 years. The Tumbalá climbing rat (Tylomys tumbalensis) is classified as Critically Endangered (Possibly Extinct) on the IUCN Red List of Threatened Species.
How this species is doing
Pressure
The area in which the species occurs has been converted to agriculture. Only very small patches of original forest vegetation remain.
Responses
There do not appear to be any conservation measures in place for this species.
Knowledge level
Virtually nothing is known about the ecology of this species. Its hind feet are modified for climbing, which suggests that it is probably arboreal. Preferred habitats for climbing rats are heavily forested areas, often around rocky ledges. Specimens have been collected both up in the trees and on the ground.