Geographic Range
Beecroft's scaly-tailed squirrels inhabit the tropical and subtropical forests of
West and Central Africa.
- Biogeographic Regions
- ethiopian
Habitat
Beecroft's scaly-tailed squirrels prefer the upper canopy levels of virgin tropical
and subtropical rainforest.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
Physical Description
Anomalurus beecrofti
is squirrel-like in form with soft, thick fur that is sometimes curly with some parts
of the pelage having long hairs with dark tips on the dorsal side. This makes the
fur look brindled, with the majority of the fur being slate-colored. The coloring
of the the ventral side of
Anomalurus beecrofti
varies. It is often slate-colored with orange tips. The fur can also appear to
be a whitish color. On the crown of the head there is a small spot of white hairs.
The throat is a greyish color. There is also a pale area at the base of the back
of the neck. The ears are smaller and more narrow than
Anomalurus derbianus
and there is no black on the ears or face.
Anomalurus beecrofti
has large eyes and long whiskers. The incisors are well-developed and the molars
are small with flat crowns. The auditory bullae are more inflated and the cheekteeth
are more narrow than
Anomalurus derbianus
. The digits are well-developed with strong claws. Beecroft's scaly-tailed squrirrels
have a gliding membrane that extends between their forelimbs and hindlimbs and between
their hindlimbs and tail. The membrane is supported by a rod of cartilage in the
front. This cartilage stems from the elbow joint instead of from the wrist, as in
true flying squirrels. There are sparse amounts of hair on the underside of the flight
membrane and large amounts of hair on the outerside. The tail is short, black and
thin-haired with 16 to 18 scales on the underside of the tail near the base. The
approximate body length is 25 to 31 cm, the approximate tail length is 19 to 23 cm,
and the approximate weight is 0.6 to 0.7 kg.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
There is no information concerning mating systems in Anomalurus beecrofti .
Information about reproduction in
Anomalurus beecrofti
is scarce. The main breeding season seems to be at the end of the rainy season in
West Africa. In general, scaly-tailed squirrels give birth to one young. The gestation
period is unknown. Newborns are large and covered with hair. They are able to open
their eyes and move around soon after birth. Copulatory plugs have been noted in
the vagina of pregnant females.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
The offspring of
Anomalurus beecrofti
are hidden in the nest and are fed by both parents until they are almost full grown.
They are fed food that is well masticated by the parents. When the parents bring
the food to their young, their cheeks are said to be swollen to the size of a tangerine.
- Parental Investment
- altricial
- male parental care
- female parental care
Lifespan/Longevity
The lifespan of
Anomalurus beecrofti
is scarcely known in the wild and in captivity. One record of an anomolurid being
held in captivity had the animal living in a cage for 14 months with a
Dendrohyrax
species. It is not known if the specimen died or was released.
Behavior
Anomalurus beecrofti
are mainly nocturnal and crepuscular. They are primarily arboreal and sleep during
the day high up on the outsides of trees in nests made of twigs and leaves, relying
on camouflage to hide from predators. This is different than other members of the
family Anomaluridae that inhabit hollow trees for rest. They may live alone or in
pairs and several squirrels may inhabit the same tree. They leave their nest at dusk
and , using their gliding membranes, glide down to lower branches to forage. The
scales on their tails are used to stop them during landing, so they do not skid.
These scales are also used to help them cling to the rough bark of the trees they
climb. They are not very comfortable on the ground and it is said that they only
reach the ground by accident or mistake. Their awkwardness on the ground is due to
their gliding membrane getting in the way of their legs when trying to walk. They
are able to run along tree branches like true flying squirrels.
Communication and Perception
The well-developed auditory bullae and relatively large ears of Beecroft's scaly-tailed
squirrels have led researchers to believe that acoustic communication is important
to them. The call of
Anomalurus beecrofti
is described as "something between a whistle and a hoot" by Rosevear (1969). Twittering
calls have also been noted to occur at night in these squirrels. In the family, Anomaluridae,
hissing sounds have been noted when these animals feel threatened. They also are
likely to use vision, touch, and chemical cues in communicating with conspecifics.
Food Habits
Beecroft's scaly-tailed squirrels are herbivorous, feeding mainly on bark, leaves,
fruit, seeds, and nuts. Their well-developed jaws are thought to be used to crack
the hard shells of nuts and to gnaw at tough outer bark.
- Plant Foods
- leaves
- roots and tubers
- wood, bark, or stems
- seeds, grains, and nuts
- fruit
Predation
There is no information available on predators of Beecroft's scaly-tailed squirrels.
They are not hunted by natives because of their small size. They may be preyed on
by large raptors, arboreal snakes, and cats. The brindled color pattern on the dorsal
side of
Anomalurus beecrofti
serves as camouflage when they are clinging to trees.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Information about the role that
Anomalurus beecrofti
plays in the ecosystem is scarce, although they do feed on fruits and seeds and may
act as a seed disperser.
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
Information about how Anomalurus beecrofti can benefit humans is scarce.
Economic Importance for Humans: Negative
There are no known adverse affects of Anomalurus beecrofti on humans.
Conservation Status
Anomalurus beecrofti
is listed as a CITES Appendix III species. This is primarily due to habitat loss
because of deforestation in West and Central Africa.
Other Comments
The systematic position of
Anomalurus beecrofti
and the entire Anomaluridae family within the order Rodentia has been greatly debated.
Despite their common name, they are not squirrels (family Sciuridae) and may not be
closely related.
Additional Links
Contributors
Amanda Merkel (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- 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.
- 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).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- male parental care
-
parental care is carried out by males
- female parental care
-
parental care is carried out by females
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals 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
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- granivore
-
an animal that mainly eats seeds
References
Feldhamer, G., L. Drickamer, S. Vessey, J. Merritt. 1999. Mammalogy: Adaptation, Diversity, and Ecology . McGraw-Hill Higher Education.
Grzimek, B. 1990. Grzimek's Encyclopedia of Mammals . New York: McGraw-Hill, Inc.
Macdonald, D. 1984. The Encyclopedia of Mammals . New York, New York: Facts on File, Inc..
Nowak, R. 1999. Walker's Mammals of the World . Baltimore, Maryland: The John Hopkins University Press.
Rosevear, D. 1969. The Rodents of West Africa . Great Britian: The Thanet Press.
CITES Secretariat--International Environment House. 2001. "Convention on International Trade in Endangered Species of Wild Fauna and Flora" (On-line ). Accessed 12/1/02 at http://www.cites.org/ .