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.
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.
Range mass: 180 to 220 g.
Range length: 18 to 23 cm.
Average length: 22 cm.
Other Physical Features: endothermic ; bilateral symmetry
Little is known about the lifespan of this species.
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.
Range elevation: 40 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest
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.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; ultrasound ; chemical
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.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
These animals are not reported to have any negative impact on humans.
These animals have no documented economic importance to humans.
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.
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.
Animal Foods: insects
Plant Foods: leaves; wood, bark, or stems; fruit; flowers
Primary Diet: herbivore (Lignivore)
Cameroon, or flightless, scaly-tailed squirrels (Zenkerella insignis) inhabit the high forests of Western central Africa, from the Cameroons to the Congo.
Biogeographic Regions: ethiopian (Native )
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.
Breeding interval: The breeding interval of Z. insignis is unknown.
Breeding season: The breeding season of this species has not been reported.
Range number of offspring: 1 to 3.
Average number of offspring: 1-2.
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); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female); pre-independence (Provisioning: Male, Female)
The Cameroon scaly-tail (Zenkerella insignis), also referred to as the Cameroon anomalure, flightless anomalure or flightless scaly-tail,[3] is a rodent species endemic to West Central Africa.[3][4][5] The scientific literature has never (or possibly only obscurely) reported observations of live individuals.[3][4][6] The taxonomic classification of the species has been subject to recent revision.
Previous common names for this species included flightless scaly-tail ‘squirrel’, but this is a misnomer as anomalures are very distantly related to the true squirrels of the rodent family Sciuridae and only superficially resemble them.[6] Z. insignis is the only extant species in the genus Zenkerella and family Zenkerellidae and is the only surviving species of a lineage that diverged from the other extant anomalures (genera Idiurus and Anomalurus) ~49 million years ago (Ma).[6] Among mammals, very few species are the sole survivors of such ancient lineages, some other examples being the pen-tailed treeshrew and the monito del monte.[7]
Extinct fossil taxa which are putative close relatives of Z. insignis include: Zenkerella wintoni (~20 Ma, early Miocene, Kenya),[8] Prozenkerella saharaensis (~31 Ma, early Oligocene, Libya),[9] and possibly Oromys zenkerellinopsis (~33 Ma, earliest Oligocene, Morocco).[10]
In 2016, it was reported that three whole-body specimens of Z. insignis were recovered on Bioko Island, Equatorial Guinea.[6] At that time, it had been over 20 years since the scientific literature recorded new individuals.[5][6] These specimens were used to sequence portions of the Z. insignis genome. Phylogenetic analysis using combined DNA and anatomical data place Zenkerella as the sister taxon of an Idiurus-Anomalurus clade.[6] This is contrary to a previous hypothesis that grouped Zenkerella with Idiurus within the family Anomaluridae.[6][9][11] The Z. insignis position in the rodent evolutionary tree supports a single origin of the anomalure gliding adaptation with no evolutionary reversals;[6] more complex evolutionary scenarios were previously envisioned.[9][12] The same analysis estimated an early Oligocene origin of anomalure gliding and an early Eocene divergence of the Z. insignis lineage.[6] These results were used to justify a taxonomic revision that erected the new rodent family Zenkerellidae in which Z. insignis is the only living species.[6]
The anomalures, including Z. insignis, are unique among rodents in having a set of scales on the ventral surface of the base of the tail.[6] These scales reportedly provide traction when climbing trees.[3][4] Z. insignis is the only anomalure that lacks patagia (membranes that span between the forelimbs and hindlimbs).[3][4] Anomalures that possess patagia are able to glide between trees. Thus, Z. insignis is unable to glide. The divergence of the Z. insignis lineage from other extant anomalures apparently occurred before the evolution of anomalure gliding.[6] Gliding is a relatively rare adaptation that has independently evolved in three lineages of extant placental mammals (anomalures, colugos, and flying squirrels).[13] Z. insignis has ashy-grey pelage and bushy black tail hair.[4][6] Tufts of short, course, and spikey hairs are located on the lateral ankles.[4][6] The hands and feet have four and five digits respectively.[4][6] Pedal digit I (the first toe) is somewhat divergent.[6]
Z. insignis molars are distinct from other extant anomalures in having a continuous enamel crest that, in occlusal view, forms a full perimeter around the tooth and a single transverse crest divides the occlusal surface into two basins.[6][9][14] The fossilized molars of Z. wintoni and P. saharaensis also have these features and the lineage's tooth morphology is essentially unchanged since the early Oligocene.[6][9] In mammals, dental morphology is an excellent indicator of the animal's diet; it therefore seems that the lineage has retained the same dietary niche for at least 31 million years.[6] Sole survivorship of an ancient lineage combined with the retention of morphology are characteristics which identify Z. insignis as a ‘living fossil’.[6] However, some biologists have questioned the usefulness of this popular term.
There are no (or possibly only obscure) entries in the scientific literature that document direct observations of living Z. insignis individuals.[3][4][6] Although the species was first described in 1898, trapping efforts have resulted in only 14 specimens deposited in world natural history museums.[5][6] From these specimens, the geographic distribution of Z. insignis is recorded from south Cameroon, Equatorial Guinea (including Bioko Island), southwestern Central African Republic, and Republic of Congo.[3][5] The species is not recorded from Gabon but probably occurs there.[3][4] Based on collection localities, Z. insignis inhabits rainforest and semi-deciduous forests.[3][5]
Without direct scientific observation, lifestyle and diet are largely inferred from what is known of other anomalures[3][4] and anecdotal information gathered by interviewing local people and subsistence trappers.[5][6] The species is probably largely arboreal[3][4][5] but occasional captures in ground snares indicates it sometimes comes to the ground.[5][6] Other anomalures are largely or exclusively nocturnal and sleep in tree-hollows during the day;[3][4] these habits may also be true for Z. insignis.[6] The species is probably herbivorous.[3][4]
The IUCN previously assessed the species as Data Deficient, but in 2008 this was changed to the current listing of Least Concern as the species appears to have a relatively wide distribution with extensive suitable habitat, and occurs in several protected areas.[2] However, some conservation biologists state that “This rating belies the fact that threats such as habitat loss and degradation are intense and widespread in central Africa” and “Zenkerella may be under greater threat”.[7]
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has generic name (help) The Cameroon scaly-tail (Zenkerella insignis), also referred to as the Cameroon anomalure, flightless anomalure or flightless scaly-tail, is a rodent species endemic to West Central Africa. The scientific literature has never (or possibly only obscurely) reported observations of live individuals. The taxonomic classification of the species has been subject to recent revision.