This species ranges from southern Mexico (Veracruz) to western Ecuador and the Cauca Valley of Colombia (Emmons and Feer 1997). It is found from sea level to 2,600 m asl in Colombia (Alberico et al.2000). To the east, this species is replaced by C. lanatus (Eisenberg 1989), and it apparently does not pass through the eastern Cordillera de los Andes.
Caluromys derbianus can be found in both highland and lowland rain forests in the region between south-central Veracruz, western Columbia, and northern Ecuador. Bucher and Hoffmann (1980)
Biogeographic Regions: neotropical (Native )
Caluromys derbianus is the largest species in the genus. It is a long, slender animal weighing from 200 to 400 grams. The common name of this opossum is derived from its woolly pelage. A dark strip is often present running from the crown to the fleshy portion of the nose. Pelage color shows much geographic variation. Its ears are creamy white to pink. All digits of the front and hind feet are clawed with the exception of the opposable hallux. The tail constitutes up to two-thirds of its total length. The latter half of the tail is naked and prehensile. Barrington and Willis (1973) ; Bucher and Hoffmann (1980)
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 330 g.
Average basal metabolic rate: 1.194 W.
Habitat and Ecology
The woolly opossum inhabits both lowland and highland rainforests to a maximum altitude of 2,460 meters. Bucher and Hoffman (1980)
Terrestrial Biomes: rainforest
Although food habits have not been investigated thoroughly, this opossum also appears to be omnivorous. Captive animals have eaten fruit, insects, and mice. They have been maintained on a laboratory diet of raw egg, fruit, and dog food. Bucher and Hoffman (1980)
Life History and Behavior
Perception Channels: tactile ; chemical
Status: captivity: 8.7 years.
Lifespan, longevity, and ageing
Litter size for C. derbianus is usually three or four, although it may be as high as six. The woolly opossums breed during the dry season (January to June) in Central America, however a few studies indicated that breeding may extend into the first few months of the rainy season (July to September). In Nicaragua it has been suggested that they breed throughout the year. The estrous cycle has an average length of 27 to 29 days and is maintained year round. The young attach to a teat after birth (in a pouch), where they are nurtured until they reach a level of development similar to young placentals at birth. Caluromys derbianus reaches sexual maturity at seven to nine months and has been reported to live in excess of five years in captivity. Bucher and Hoffman (1980) ; Dawson (1983)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average number of offspring: 3.
Average age at sexual or reproductive maturity (male)
Sex: male: 240 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 240 days.
Molecular Biology and Genetics
Statistics of barcoding coverage: Caluromys derbianus
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
- Least Concern (LC)
- 1996Vulnerable (VU)
The woolly opossum has no special conservation status. (Bucher-Hoffman, 1980.)
IUCN Red List of Threatened Species: least concern
Relevance to Humans and Ecosystems
Once hunted for its fur, and possible important as a disperser of tropical trees. Bucher and Hoffman (1980)
Derby's woolly opossum
C. derbianus weighs between 200 and 400 grams (7.1 and 14.1 oz). The length of the head and body is between 180-290 mm and tail length adds 270-490 mm. Its fur is very woolly in texture and tends to be fine.  Coloration varies geographically but the animal often possesses a dark strip running from the top of the head to the nose.  The face varies from a light creamy white or buffy color and the back is red-brown. The belly is a yellowish-white.  Some individuals have a gray patch between the shoulders, but this varies geographically. Juveniles may appear more gray then adults.  The digits are clawed with the exception of the opposable thumb. The prehensile tail is longer than the head and body, making up two thirds of the animal's total length. The distal half of the tail is naked, and is an identifying feature. Other species in the area possess tails with fur covering more of the tail.  C. derbianus females develop a brood pouch on their undersides while carrying young. [3, 4] Once offspring leave the pouch, it shrinks into small skin folds.  One study identified 37 caudal vertebrae, however that may vary between individuals.  The skull can be identified by very large zygomatic arches. 
C. derbianus is primarily arboreal, living in tree hollows or on branches. It lives in highland and lowland rainforests, typically are nearby a stream or other source of water. It is found at altitudes up to 2,600 m (8,500 ft).
C. derbianus is omnivorous, feeding on a variety of food sources including fruits, nectar, invertebrates, leaves, seeds, and small vertebrates such as mice. [4, 5, 6] The animal hunts nocturnally and is a valuable pollinator for species such as Marcgravia nepenthiodes, a flowering plant. 
C. derbianus could be locally threatened by deforestation, but is considered common throughout its range.  Populations are sustained due to a lack of prominent predators and broad habitat tolerance.  In the past, C. derbianus has trapped for its fur, however there is no longer a demand for the skins. 
Reproduction and Life Cycle
C. derbianus reaches sexual maturity at seven to nine months. They are estrous, with cycles lasting approximately 27-29 days.  Mating season is not well known. A Nicaraguan study found mating season to be year round, while other studies determined that mating season continues throughout the dry season (January to July). After birth, the young are kept in the mother’s pouch attached to a teat until they reach a level of maturity similar to that of a placental animal at birth.  Sexual maturity is reached at seven to nine months.  Average litter size is 3-4, however some may be as large as 6.  C. derbianus has been found to survive up to 5 years in captivity, and most likely has a shorter life span in the wild.
C. derbianus is a solitary animal and has a small home range consisting of a few close trees.  Males are usually more active than females, and peak activity for both tends to be within a few hours of either the beginning or end of a day.  This species moves in a trot-like gait, often using its tail for both balance and as a gripping mechanism.  The tail may also be used to carry items such as plant material for nests.  A defensive stance, involving both hind legs and one foreleg on the ground with the second foreleg raised, may be assumed if a threat is perceived.  If very threatened, the animal may leap towards the offender and bite at it, although it prefers to retreat. 
This species sleeps in a ball with its tail wrapped around its body 
Etymology of Name
This species came into the possession of the 13th Earl of Derby (1775-1851) not later than 1834, although there is no record of when and from where nor is there any evidence that the animal was ever alive in the Knowsley Menagerie. In 1841 Lord Derby's specimen was the model for the type description of Didelphys derbianus, written by the then curator at the Zoological Society of London, George Waterhouse. Waterhouse stated that he had 'taken the liberty of naming it' after the 13th Earl. Only in 1999 was it realized that a watercolour by Edward Lear, dated 18 March 1834 and painted at Knowsley Menagerie, referred to this species. It was previously overlooked because the subject was identified as a 'Tree Rat'. The model for Lear's watercolour would later become the holotype of Caluromys derbianus.
- Lew, D., Soriano, P., Cuarón, A. D., Emmons, L., Reid, F. & Helgen, K. (2008). Caluromys derbianus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 28 December 2008. Database entry includes justification for why this species is of least concern
- Gardner, A. L. (2005). "Order Didelphimorphia". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. p. 3. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Gardner, Alfred L. (2007), "Caluromys derbianus", in Gardner, Alfred L., Mammals of South America, Volume 1: Marsupials, Xenarthrans, Shrews, and Bats, Chicago: University of Chicago Press, pp. 39–116 (p. 100), ISBN 978-0-226-28240-4
4. Nowak, R. "Marsupialla." Walker's Mammals of the World. 5th ed. Baltimore, MD: Johns Hopkins Univ. Pr., 1991. 23-25. Print.
5. "Caluromys Derbianus." Mammalian Species. New York: American Society of Mammalogists, 1969. N. pag. Print.
6. Emmons, L., and F. Feer. "Didelphidae." Neotropical Rainforest Mammals: A Field Guide. Chicago: U of Chicago, 1990. 13. Print.
7. Cable, R. "Caluromys Derbianus." Animal Diversity Web. N.p., 2013. Web. 2 May 2014.
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