Family NESOMYIDAE
Prionomys batesi Bates’s African Climbing Mouse (Dollman’s African Tree Mouse) Fr. Souris arboricole de Bates; Ger. Bates Klettermaus Prionomys batesi Dollman, 1910. Two new African mammals. Ann. Mag. Nat. Hist., ser. 8, 6: 226. Dja River, Bitye, Cameroon. 2000 ft (618 m).
Taxonomy Closely related to Dendromus and Dendroprionomys (see genus profiles). Synonyms: none. Chromosome number: not known. Description Very small mouse with long tail. Pelage short, dense, soft and woolly. Dorsal pelage brownish-grey; hairs dark grey at base, brown at tips. Mid-dorsal stripe absent. Flanks pale grey; hairs dark grey at base, pale grey at tips. Ventral pelage pale grey, similar to flanks; hairs grey at base, paler at tips. Head similar in colour to dorsal pelage. Conspicuous brown eye-ring. Long stiff vibrissae. Ears moderate, darkly pigmented, with sparse brown hairs. Chin, throat and chest grey. Limbs short, with few short hairs. Forefoot with four digits: Digit 1 absent, Digits 2, 3, 4 and 5 thin, each with small pale claw. Large carpal tuberosity on ‘hand’. Hindfoot with five digits: Digit 1 shorter than other digits, with ‘nail-like’ claw, Digits 2, 3, 4 and 5 long and thin, each with small claw; Digit 1 opposable (cf. Digit 5 opposable in Dendromus and Dendroprionomys) (Figure 30); three large callosities at base of digits on hindfoot. Tail long (ca. 122% of HB), brown, with scales arranged in rings; few (if any) small bristles. Skull: upper incisors pro-odont without longitudinal grooves, braincase globular-shaped, molar teeth with tall pointed cusps (Figure 34). Nipples: not known. Geographic Variation None recorded.
Figure 34. Skull and mandible of Prionomys batesi (BMNH 11.5.5.9, holotype).
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Similar Species Dendromus spp. Cheekteeth molariform; incisor teeth orthodont. Dendroprionomys rousseloti. Cheekteeth with tall pointed cusps; incisor teeth orthodont. Distribution Endemic to Africa. Rainforest BZ (West Central Region, Gabon Sub-region). Recorded from Cameroon, S Central African Republic and W Congo (Odzalla). Habitat Rainforest, especially where there are small shrubs and lianas. Abundance Uncertain; known only from a few specimens at five localities. Adaptations Terrestrial and arboreal. Bates’s African Climbing Mice climb on thin branches, twigs and lianas using the prehensile tail, long digits, callosity on the forefoot and opposable Digit 1 of hindfoot (in a similar way to Dendromus spp.). Burrows are made by digging in forest soil using the pro-odont upper and lower incisor teeth; each burrow is indicated by a little hillock of soil, ca. 30 cm diameter, without a visible entrance hole.The burrow contains a small nest chamber lined with dry leaves. Activity is entirely nocturnal: one individual emerged at 21:00h (three hours after nightfall) and climbed rapidly into nearby shrubs and lianas. Activity alternated between climbing (and foraging) in the forest and 15-minute ‘rest’ periods in the nest (F. Petter unpubl.). Bates’s African Climbing Mice emit a strong odour, not unlike that of some species of shrews.
Prionomys batesi