Graphiurus surdus Dollman 1912
Creators: name: Don E. Wilson
name: Thomas E. Lacher, Jr
name: Russell A. Mittermeier
Publisher: name: Lynx Edicions
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Gliridae
Graphiurus
Graphiurus surdus

description: 15.
Short-eared African Dormouse
Graphiurus surdus
French: Loir sourd / German: Kurzohrbilch / Spanish: Liron de orejas cortas
Other common names: Deaf Dormouse, Silent Dormouse
Taxonomy. Graphiurus surdus Dollman, 1912,
Benito River, Rio Muni Province, western Equatorial Guinea.
Placed in the subgenus Graphiurus. Although described and initially recognized as a valid species, X. Misonne in 1974 and H. Genest-Villard in 1978 synonymized G. surdus within a broadly defined G. murinus. L.. W. Robbins and D. A. Schlitter in 1981 and M. E. Holden in 1996 provided morphological evidence for recognizing G. surdusas a valid species. In his original description ofthe type specimen in 1912, J. G. Dollman remarked that this is *"...a small-eared species” and chose the Latin species name surdus, which translates to mean deafor silent. These dormice are certainly not deaf, and being silent has nothing to do with small ear size, and so the common name “Short-eared Dormouse” seems most appropriate. In 1981, Robbins and Schlitter questioned whether small ears were diagnostic. Holden in 1996 compared mean ear length of G. surdus to G. christyi, the dormouse that most closely resembles G. surdus in external appearance, and documented that ear length is shorter in G. surdus; limits of the ranges are close but do not overlap. It is difficult to separate the two species based on ear length alone if specimens being examined happen to be at the extremes of measurement ranges, but other characteristics such as pelage texture, length of hindfeet, and cranial characters allow for unambiguous identification of G. surdus. Holden in 1996 and 2013 provided additional comparisons with G. christy: and other species. Monotypic.
Distribution. WC & C Africa, in S Cameroon, Equatorial Guinea, N Gabon, and two localities in NE & SC DR Congo (Masako and Inkongo). Limits of geographic distribution unknown.
Descriptive notes. Head-body 87-110 mm, tail 66-82 mm, ear 9-14 mm, hindfoot 18-22 mm; weight 18-34 g. No sexual dimorphism has been reported. Dorsal pelage ofthe Short-eared African Dormouse is grayish brownto charcoal; textureis silky and fur is moderately long (rump hairs 5-7 mm, guard hairs up to 11 mm). Ventral pelage is dark gray, washed with whitish buff; dorsal and ventral pelage colors are not clearly delineated. Cheeks are gray washed with white and not much paler than dorsal pelage. Eyes are large, and eye mask is inconspicuous; eyes are encircled by thin dark eyerings. Ears are brown, somewhat short, and rounded; post-auricular patches are not present. Hindfeet are cream, or white with dark metatarsal streak, and are relatively long compared with most African dormice, ¢.21% of head-body length. Tail is somewhat short, ¢.73% of head-body length, and is similar in color to dorsal pelage, with many scattered white hairs resulting in a frosted appearance, but tip is not white. Tail hairs are shorter at base, 3-8 mm, and longer at tip, up to 20 mm. A diagnostic feature of cranium ofthe Short-eared African Dormouse is relatively straight conformation of zygomatic arch in lateral view. Greatest length ofskull is 26-5-29-4 mm, zygomatic breadth is 13-4-15-7 mm, and upper tooth row length is 2:9-3-5 mm. External and cranial measurementslisted based on specimens from Cameroon, Equatorial Guinea, and Gabon. Chromosome number is not known. Females typically have four pairs of nipples (I pectoral + 1 abdominal + 2 inguinal = 8), although Robbins and Schlitter reported a female from south-eastern Cameroon with only three pairs (1 pectoral + 0 abdominal + 2 inguinal).
Habitat. Primary and secondary lowland tropical rainforest in faunal zones identified as important reservoirs for biodiversity and speciation. In south-western Cameroon, one Short-eared African Dormouse was collected in the same trap line as the Thicktailed African Dormouse (G. crassicaudatus). Traps were set on vines and horizontal branches in secondary high forest, with no hollow trees observed in the immediate area. In DR Congo, one individual was captured on the ground at Masako; habitat in the vicinity of Masako is composed of primary and old-growth secondary forest, fallow lands, and cultivated areas.
Food and Feeding. Short-eared African Dormice are probably omnivorous like other members of this genus, and they likely consume arthropods, fruit, nuts, and seeds. In southern Cameroon and north-eastern DR Congo, individuals were attracted to bait made from nuts of the African oil palm (Llaeis guinensis).
Breeding. There is no specific information available for this species, but a female Short-eared African Dormouse was found pregnant with two embryos in January in south-western Cameroon.
Activity patterns. There is no specific information available for this species, but the Short-eared African Dormouse is probably nocturnal.
Movements, Home range and Social organization. The Short-eared African Dormouse is probably arboreal and likely solitary. One individual from Bitye, Cameroon, was smoked out ofa hollow tree. This suggests that Short-eared African Dormice at least sometimes nest in hollow trees, as do the Thick-tailed African Dormouse and Nagtglas’s African Dormouse (G. nagtglasii) Little is known about abundance or density of the Short-eared African Dormice, but existence of less than 25 identified museum specimens, despite intensive small mammal surveys in certain parts ofits distribution, suggests that it is rare.
Status and Conservation. Classified as Data Deficient on The IUCN Red List. There is continuing uncertainty as to geographical limits, natural history, and potential threats of the Short-eared African Dormouse. Based on paucity of museum specimens, it is not abundant; furthermore,its ability to tolerate modifications of habitat has not been studied.
Bibliography. Amundala et al. (2005), Colyn (1986, 1991), Dollman (1912), Genest-Villard (1978), Holden (1996b, 2005, 2013), Misonne (1974), Mukinzi et al. (2005), Robbins & Schlitter (1981), Schlitter (2008c), Van der Straeten & Dudu (1990).
description: Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Gliridae, pp. 838-889 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on pages 849-850, DOI: 10.5281/zenodo.6604339