Geographic Range
Cameroon, or flightless, scaly-tailed squirrels (
Zenkerella insignis
) inhabit the high forests of Western central Africa, from the Cameroons to the Congo.
Habitat
The principle habitat of Cameroon Scaly-tails is tropical forests. The species has
only been found from Cameroon to Gabon, and is thought to occupy the canopy.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
Physical Description
Z. insignis
is small, weighing 180 to 220 g. The head and body length is between 18 and 23 cm.
This species has a dense, soft, slate grey fur, with ochre tints on the forearms,
lower shins, and cheeks. It has a lighter underside, and a darker, bushy tail that
measures 15 to 17 cm in length. The ankles also have a tuft of darker ‘spoon-hairs’,
which cover a glandular area. The function of this glandular area is still not known.
Z. insignis
resembles the other members of its family (
Anomaluridae
), possessing two rows of pointed scales on the underside of the tail near the base.
These scales are thought to prevent slipping when at rest while climbing. Cameroon
scaly-tails differ from their closest relatives in that this species is the only member
of the family which does not possess a gliding membrane. Members of the species are
therefore sometimes referred to as flightless scaly-tailed squirrels. Members of
Anomaluridae
are noted to have very well-adapted 'bat-like' claws, and very large eyes.
- Other Physical Features
- endothermic
- bilateral symmetry
Reproduction
Little is known about the reproductive behavior of
Zenkerella
. However members of the family
Anomaluridae
are believed to live singly or in mated pairs.
Details on the reproductive behaviors of this species are lacking. Members of the
family
Anomaluridae
most likely have one or two offspring at a time, but have been noted to have up to
three precocious young. The timing of sexual maturity, age to independence, age at
weaning, gestation period, size at birth, and breeding season are not known.
- Key Reproductive Features
- iteroparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
Anomalures are born precocious, with their eyes open and with a thick coat of fur.
Their mothers provide milk, and the young grow quickly. They are weaned on pre-chewed
food from the cheek pouches of both parents. It is reasonalbe to think that
Z. insignis
bears similarity to other members of its family in these areas.
- Parental Investment
- no parental involvement
- precocial
- male parental care
- female parental care
-
pre-fertilization
-
protecting
- female
-
protecting
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
provisioning
-
pre-independence
-
provisioning
- male
- female
-
provisioning
Lifespan/Longevity
Little is known about the lifespan of this species.
Behavior
Very little is known about the habits of this anomalurid. All other members of this family are nocturnal, but Cameroon scaly-tails are thought to be diurnal due to their inability to glide.
The is specialized for an arboreal life; its distinctive scales aid in grasping trees
to prevent it from slipping.
Home Range
The home range size for these animals has not been reported.
Communication and Perception
Members or this family have very well developed bi-focal vision, an excellent sense
of smell, and acute, possibly ultrasonic, hearing. They are believed to depend on
scents, as well as sounds for communication. Twittering calls have been noted.
- Perception Channels
- visual
- tactile
- acoustic
- ultrasound
- chemical
Food Habits
The diet of
Z. insignis
has not been reported. However, they are probably like other members of their family
with respect to diet. Members of the family
Anomaluridae
have been successful due to the specificity of their diet. Their primary food source
is the bark which they gnaw from a small group (about a dozen specific species) of
trees. The location of these trees is indicative of the locations of anomalures.
Anomalurids have also been known to eat fruits, leaves, and flowers. They also probably
eat small invertebrates: insects, larvae, and grubs.
- Primary Diet
-
herbivore
- lignivore
- Animal Foods
- insects
- Plant Foods
- leaves
- wood, bark, or stems
- fruit
- flowers
Predation
Little is known about predation on Z. insignis . It is likely that they might be prey to diurnal predators capable of gleaning them from the canopy of the forest.
Ecosystem Roles
The role of
Z. insignis
in the ecosystem has not been commented on in the literature. However, it is likely
that they have a role similar to that of other members of their family. Members of
this family are believed to greatly impact their ecosystem via a mutually beneficial
relationship they have co-evolved with their food trees. Anomalures can use their
incisors not only to eat, but also to cut small branches off trees. They use this
ability to cut the tops off of young trees, a behavior called pruning, which kills
young competitors near the base of their food trees. This pruning may provided their
food trees with a competitive advantage. It has been observed that these specific
trees are often dominant or are common in the areas where members of this family,
Anomaluridae
, are known to live.
Economic Importance for Humans: Positive
These animals have no documented economic importance to humans.
Economic Importance for Humans: Negative
These animals are not reported to have any negative impact on humans.
Conservation Status
Z. insignis
is extremely rare with an unknown status. It is listed, by the International Union
for Conservation of Nature and Natural Resources, as lower risk in the near threatened
category.
Additional Links
Contributors
Nancy Shefferly (editor), Animal Diversity Web.
Michelle Harvey (author), Michigan State University, Barbara Lundrigan (editor, instructor), Michigan State University.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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).
- 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.
- young precocial
-
young are relatively well-developed when born
- 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.
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- 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
- ultrasound
-
uses sound above the range of human hearing for either navigation or communication or both
- chemical
-
uses smells or other chemicals to communicate
- herbivore
-
An animal that eats mainly plants or parts of plants.
- 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.
References
Bigalke, R. 1968. The Contemporary Mammal Fauna of Africa (in Evolution of Mammals on Southern Continents). The Quarterly Review of Biology , 43: 265-300. Accessed March 16, 2004 at www.jstor.org .
Booth, A. 1958. The Niger, The Volta and the Dahomey Gap as Geographic Barriers. Evolution , 12: 48-62. Accessed March 16, 2004 at www.jstor.org .
Dorst, J., P. Dandelot. 1972. A Field Guide to the Larger Mammals of Africa . St. James Place, London: Collin.
Kingdon, J. 1997. The Kingdon Field Guide to African Mammals . San Diego, California: Academic Press.
Nowak, R. 1997. "Walker's Mammals of the World" (On-line). Accessed March 16, 2004 at http://www.press.jhu.edu/books/walkers_mammals_of_the_world/rodentia/rodentia.anomaluridae.zenkerella.html .