Like other species within the Tylomys genus, the Tumbala climbing rat (Tylomys tumbalensis) is a very large, elusive rodent. Most of what is known about this particular species comes from a single immature specimen collected by the U.S. National Museum in 1895 (2) (3), and the Tumbala climbing rat is said to resemble a larger version of the common black rat (Rattus rattus) (4).
The Tumbala climbing rat has long, thick, woolly fur (3) and is greyish-brown in colour (2) (3) (4) with darker areas on the top of its head and a blackish streak along its back (2). The sides are washed brownish (2) while the underside tends to be lighter shades, such as a buffy-grey or creamy-white (2) (3) (4).
The Tumbala climbing rat has a shiny tail (3), which is longer than the length of its body (5) and is black close to the body but becomes yellowish-white from about halfway down right to the tip (2) (3). The slender tail is naked or sparsely haired (3) (4) (6), and large scales form rings along its length (3). The Tumbala climbing rat’s ears are large, naked and blackish (2) (3) (4).
Although climbing rats are generally rather slow moving animals, they are able to demonstrate great agility and speed as they move through the vines and branches of their forest home (3). The Tumbala climbing rat has a specialised hind foot which is well adapted for climbing among trees (4) (6).
A specimen of the Tylomys genus was said to have emitted cat-like spitting sounds as well as pig-like shrieks in captivity (7).
- Also known as
- Tumbalá climbing rat, Tumbala climbing-rat.
- Head-body length: c. 21 cm (2)
- Tail length: c. 23 cm (2)
Tumbala climbing rat biology
Very little is known about the specific biology of the Tumbala climbing rat, as only one specimen has ever been captured, and this was an immature male in 1895 (2). However, individuals of the Tylomys genus are reported to be nocturnal (3), and the rat’s modified hind feet indicate that it is an arboreal species (4) (6) (9).
Female Tylomys reach sexual maturity at about 90 days and males at around 144 days (10). Pregnancy in these rodents lasts for about 40 days, with each litter comprising between one and four young (11).
There is no information available on the diet of the Tumbala climbing rat. However, a captive Peters’s climbing rat (Tylomys nudicaudus), a close relative of the Tumbala climbing rat, was fed on bird seed, mouse breeder food and sometimes even lettuce and apples, suggesting that the genus is herbivorous (7).
Tumbala climbing rat range
The Tumbala climbing rat is known to only live in a single region of southern Mexico, a town called Tumbalá in the state of Chiapas, from which this species gets its name (1) (3) (4) (8). This rodent is only found in an area of less than 100 square kilometres (1).
Tumbala climbing rat habitat
Species within the Tylomys genus, such as the Tumbala climbing rat, generally prefer areas of dense tropical forest (1) (4), and are often found on and around rocky ledges and cliffs (4). The single locality at which the Tumbala climbing rat is known to live has an elevation of 1,700 metres (3).
Tumbala climbing rat status
The Tumbala climbing rat is classified as Critically Endangered (CR) on the IUCN Red List (1).
Tumbala climbing rat threats
The fact that, worldwide, the Tumbala climbing rat is only known from one small Mexican town means that any destruction in this area will have a severe impact on the rat’s numbers. The area of Mexico where this species lives has been significantly affected by deforestation, leaving only very small areas of the original dense tropical forest for the native species. This deforestation is the result of agricultural development in the area (1).
It is very difficult to gather a complete picture of the Tumbala climbing rat’s conservation status, as Tylomys species are reported to be particularly hard to catch (7). These rodents are so large that they have been known to break out of cages and traps set for them (12). The last known sighting of this Mexican tree-dwelling climbing rat was in 1968 (13).
Tumbala climbing rat conservation
Although there are no official conservation strategies known to be in place for the Tumbala climbing rat (9), this species is legally protected by the Mexican government (1).
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- An animal which lives or spends a large amount of time in trees.
- A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.
- Having a diet that comprises only vegetable matter.
- Active at night.
IUCN Red List (November, 2012)
Merriam, C. (1901) Seven new mammals from Mexico, including a new genus of rodents. Proceedings of the Washington Academy of Sciences, 3: 560-561. Available at:
Reid, F. (2009) A Field Guide to the Mammals of Central America and Southeast Mexico. Oxford University Press, New York.
Nowak, R. (1999) Walker's Mammals of the World. Volume 1. Sixth Edition. The Johns Hopkins University Press, Baltimore, Maryland.
Eisenberg, J. and Redford, K. (1999) Mammals of the Neotropics. Volume 3. The Central Neotropics: Ecuador, Peru, Bolivia, Brazil. Chicago University Press, Chicago.
Ellerman, J.R. (1941) The Families and Genera of Living Rodents. Volume 2. Family Muridae. The British Museum, London. Available at:
Baker, R. and Petersen, M. (1965) Notes on a climbing rat, Tylomys, from Oaxaca, Mexico. Journal of Mammalogy, 46(4): 694-695.
Wilson, D. and Reeder, D. (2005) Mammal Species of the World: A Taxonomic and Geographic Reference. Volume 2. The Johns Hopkins University Press, Baltimore, Maryland.
EDGE - Tumbalá climbing rat (July, 2013)
Hayssen, V., van Tienhoven, A. and van Tienhoven, A. (1993) Asdell's Patterns of Mammalian Reproduction: A Compendium of Species Specific Data. Cornell University Press, New York.
Helm, J. III and Dalby, P. (1975) Reproductive biology and postnatal development of the neotropical climbing rat, Tylomys. Laboratory Animal Science, 25(6): 741-747.
Kuns, M. and Tashian, R. (1954) Notes on mammals from northern Chiapas, Mexico. Journal of Mammalogy, 35(1): 101-102.
Fisher, D. and Blomberg, S. (2012) Inferring extinction of mammals from sighting records, threats, and biological traits. Conservation Biology, 26(1): 57-67.