Geographic Range
Borneo black-banded squirrels (
Callosciurus orestes
) are found only on the island of Borneo in southeast Asia (Payne and Francis, 1985).
Habitat
Borneo black-banded squirrels (
Callosciurus orestes
) can be found actively using small and intermediate sized trees at middle elevations.
Specific cover types the squirrel utilizes include lower montane forests as well as
upper dipterocarp forests (Payne and Francis, 1985).
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- rainforest
- mountains
Physical Description
The upper parts of the body in Borneo black-banded squirrels (
Callosciurus orestes
) are speckled with brown fur. A pale marking can be found behind each ear. The ventral
side is mostly grey, with a reddish tinge found in some individuals. A lateral stripe
runs along the side of the body and is black and white in color. The tail of the squirrel
has a ringed pattern which alternates between light and dark coloring the entire length
of the tail (Payne and Francis, 1985).
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
Reproduction
Little information is available on mating systems of Borneo black-banded squirrels.
However, tree squirrels in the same genus (
Callosciurus
) and geographical location are polygynandrous and mate in bouts where visual cues
and vocalization is used (Tamura, 1993).
- Mating System
- polygynandrous (promiscuous)
Little information is available about the mating behavior of Borneo balck-banded squirrels.
However, mating behavior of the congeneric
Callosciurus nigrovittatus
, formerly known as the same species, is present in the literature (Payne and Francis,
1985). These tree squirrels breed year round, but pregnancies in females are noticeably
higher in the months of April to June than the rest of the year. The number of offspring
females produce from a pregnancy is 2 to 4, with an average litter size of 3 individuals
(Moore, 1961).
- Key Reproductive Features
- iteroparous
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
Little is known about parental investment in young Borneo black-banded squirrels.
- Parental Investment
- female parental care
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
Lifespan/Longevity
Little information is available on the lifespan and longevity of Borneo black-banded
squirrels.
Behavior
There is little information on behavior in Borneo black-banded squirrels in the literature.
Species in the genus
Callosciurus
are social animals and communicate with each other visually and vocally. Tree squirrels
in this genus live in trees and on the ground in groups and forage during the day
(Tamura and Yong, 1993).
Home Range
There is little information know about the home ranges of Borneo black-banded squirrels.
Home ranges of
Callosciurus
and other tree squirrels in tropical forests are possibly influenced by vegetation
characteristics and forest structure (Saiful et al., 2001).
Communication and Perception
Little information is available on communication of Borneo black-banded squirrels.
Communication studies have been done on squirrel species of the same genus and geographic
range, particularly with their close relative, black-striped squirrels (
Callosciurus nigrovittatus
). Members of the genus
Callosciurus
communicate alarm signals to other squirrels when predators are detected. This communication
includes vocalizations of repetitious barks, squeaks, and rattles. Visual cues such
as foot-stamping and tail-flicking accompanied the vocalizations to warn other squirrels
of a predator (Tamura and Yong, 1993).
Food Habits
Borneo black-banded squirrels consume a variety of plant and animal forage. Native
fruits, as well as black ants, have been found in stomach contents of these squirrels
(Payne and Francis, 1985). Although not much information is available on the diet
of Borneo black-banded squirrels, closely related species feed on tree seeds and plant
materials, along with some insects and fungi (Bertolino and Lurz, 2013).
- Primary Diet
- omnivore
- Animal Foods
- insects
- Plant Foods
- seeds, grains, and nuts
- fruit
- flowers
- Other Foods
- fungus
Predation
Although there is little information available on predators of Borneo black-banded
squirrels, there are known predators of a closely related species, black-striped squirrels
(
Callosciurus nigrovittatus
), which inhabit the same geographic region and which were formerly considered the
same species. Predators of black-banded squirrels include felids, canids, raptors,
and snakes (Tamura and Yong, 1993).
- Anti-predator Adaptations
- aposematic
Ecosystem Roles
Borneo black-banded squirrels play a major role in the ecosystems they inhabit. Their
diet consists of seeds and fruits which allows them to play a role in the dispersal
of food plants (Payne and Francis, 1985). These squirrels also serve as prey items
for many carnivores in the ecosystem including felids, canids, raptors, and snakes
(Tamura and Yong, 1993).
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
Borneo black-banded squirrels are members of the genus
Callosciurus
, which consist of tree squirrels, many of which are important to the pet trade (Bertolino
and Lurz, 2013).
- Positive Impacts
- pet trade
Economic Importance for Humans: Negative
Borneo black-banded squirrels are members of the genus
Callosciurus
which contains tree squirrels which are important to the pet trade. The use of these
squirrels as pets has led to the introduction of some of these species to parts of
the world where they are not native. Many of the squirrel species in this genus can
readily adapt to new environments and cause ecological problems (Bertolino and Lurz,
2013).
Callosciurus orestes
, although still endemic to the island of Borneo, has the potential to be introduced
to other parts of the world and cause ecological, and in turn, economic problems for
humans.
Conservation Status
Borneo black-banded squirrels ( Callosciurus orestes ) are a species of least concern according to its status on the IUCN Red List.
Additional Links
Contributors
Reuben Frey (author), University of Wisconsin-Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point.
- oriental
-
found in the oriental region of the world. In other words, India and southeast Asia.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- female parental care
-
parental care is carried out by females
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- aposematic
-
having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.
- pet trade
-
the business of buying and selling animals for people to keep in their homes as pets.
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
References
Bertolino, S., P. Lurz. 2013. Callosciurus squirrels: worldwide introductions, ecological impacts and recommendations to prevent the establishment of new invasive populations. Mammal Review , 43/1: 22-33. Accessed April 30, 2014 at http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2907.2011.00204.x/pdf .
Duckworth, J., B. Lee, R. Tizard. 2014. "Callosciurus orestes" (On-line). The IUCN Red List of Threatened Species. Accessed April 30, 2014 at http://www.iucnredlist.org/details/3601/0 .
Moore, J. 1961. Geographic variation in some reproductive characteristics of diurnal squirrels.. Bulletin of the American Museum of Natural History , 122/1: 1-32. Accessed May 01, 2014 at http://digitallibrary.amnh.org/dspace/handle/2246/1215 .
Payne, J., C. Francis. 1985. A Field Guide to the Mammals of Borneo . Kota Kinabalu, Sabah, Malaysia: The Sabah Society.
Saiful, A., A. Idris, Y. Rashid, N. Tamura, F. Hayashi. 2001. Home Range Size of Sympatric Squirrel Species Inhabiting a Lowand Dipterocarp Forest in Malaysia. Biotropica , 33/2: 346-351. Accessed May 01, 2014 at http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7429.2001.tb00186.x/pdf .
Tamura, N., H. Yong. 1993. Vocalizations in Response to Predators in Three Species of Malaysian Callosciurus (Sciuridae). Journal of Mammology , 74/3: 703-714. Accessed May 01, 2014 at http://www.jstor.org/stable/1382292 .
Tamura, N. 1993. Role of Sound Communication in Mating of Malaysian Callosciurus (Sciuridae). Journal of Mammology , 74/2: 468-476. Accessed May 01, 2014 at http://www.jstor.org/stable/1382404 .