Graphiurus murinus (Desmarest, 1822)
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publication ID |
https://doi.org/ 10.5281/zenodo.6604339 |
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DOI |
https://doi.org/10.5281/zenodo.6604264 |
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persistent identifier |
https://treatment.plazi.org/id/9B215C43-FFCC-DD0A-C97F-F719FE54F41C |
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treatment provided by |
Carolina |
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scientific name |
Graphiurus murinus |
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11. View On
Forest African Dormouse
Graphiurus murinus View in CoL
French: Loir murin / German: Afrikanischer Bilch / Spanish: Lirén de bosque
Other common names: Woodland Dormouse
Taxonomy. Myoxus murinus Desmarest, 1822 ,
Cape Province, Cape of Good Hope, South Africa.
Placed in the subgenus Graphiurus . More than 75 scientific names have been proposed for African dormice; many are synonyms of either G. murinus that is usually associated with forest habitats or G. microtis that is generally associated with woodland savanna habitats. Even more confusing, in some publications covering southern and eastern African small mammals, both species are often listed together as a single species, G. murinus , but then characterized as inhabiting woodland savanna habitat usually associated with G. microtis , and in those publications the common name “Woodland Dormouse” is often used. Future systematic revisions will certainly reveal that this species is in reality a complex of several species; the taxon as currently understood simply refers to a general size grade of dormouse that occurs in forested habitats vs. those that dwell in woodland savanna. The species accounts for G. murinus and G. macrotis are thus truly composite accounts; they are necessarily generalized, are sometimes contradictory, and are a basic overview of the medium-sized dormice that inhabit much of the forest and woodland savanna habitats throughout central, eastern, and southern Africa. Molecular sampling combined with fine-tuned morphological analyses is required to definitively determine which names apply to which populations over their vast distributions; meanwhile, synonymies and distributions of M. E. Holden in 2005 and 2013 are followed herein. Publications cited under each species account may refer to this species under different names, but only sections clearly attributable to a particular species are pertinent. Despite attempts to separate locality and habitat records for G. microtis vs. G. murinus , some areas mapped based on literature records might be records of G. murinus or another species. Significant morphological and ecological geographical variation exists, but not all subspecific names can be assigned with certainty to distinctive populations. Monotypic.
Distribution. E & S Africa, from C & SW Ethiopia S patchily through W & SE Kenya, E & SW Uganda, W Rwanda, W Burundi, NE, NW, SE & SW Tanzania, N Malawi, extreme NE Zambia, E Zimbabwe, and extreme W & S Mozambique, to NE & SE & S South Africa, S Swaziland, and Lesotho. View Figure
Descriptive notes. Head-body 87-117 mm, tail 72-89 mm, ear 14-16 mm, hindfoot 16-19 mm; weight 24-34 g. Sexual dimorphism reported for two out of 29 cranial measurements; this is an unusual finding for African dormice. Dorsal pelage of the Forest African Dormouse varies from dark gray, grayish brown, to golden brown, sometimes with reddish or coppery hue, darkening inconspicuously toward midline in some individuals, but never exhibiting definitive mid-dorsal stripe. Fur texture is soft and silky, sometimes piled; rump hairs are 7-8 mm; and guard hairs are up to 13 mm. Ventral pelage is gray, lightly washed with white or cream. Dorsal and ventral pelage colors are usually not clearly delineated. Head color matches that of dorsal pelage. Cheeks are cream or white. Eyes are large; eye mask is conspicuous in some populations, with only narrow eye-rings in others. Ears are brown, medium-sized, and rounded; post-auricular patches are usually not present. Hindfeet are usually white or cream with dark metatarsal streak, c.18% of head-body length. Tail is moderately long, ¢.79% of head-body length; tail hairs are shorter at base, 2-4 mm, and longer at tip, up to 21 mm. Tail is usually uniform in color, matching that of dorsal pelage; white hairs are sometimes mixed inconspicuously in tail, and tip is usually not white, although some populations exhibit faint white tail tip. Skull is moderately long, and auditory bullae are not inflated to moderately inflated. Greatest length of skull is 28-8-29-3 mm, zygomatic breadth is 15-16-4 mm, and upper tooth row length is 3-2-3-5 mm. External and cranial measurements listed are based on specimens from South Africa, King William's Town, Pirie Forest; weight values from specimens captured at Great Fish River Nature Reserve complex, South Africa. Chromosome number is 2n = 46. Females have four pairs of nipples (1 pectoral + 1 abdominal + 2 inguinal = 8).
Habitat. Usually associated with forest habitats from sea level to elevations of ¢.4100 m, within the following biotic zones: Afro-montane and Afro-alpine in eastern and southern Africa, Highveld and Coastal Forest Mosaic ecoregions in the southern part of the range. Variety of forest types inhabited Forest African Dormice is varied and includes Afro-montane, plateaus, riverine, and coastal. They are less commonly recorded in montane grassland with large boulders or rocks, giant groundsel, or trees, and they are rarely caught in savanna or woodland. For example, in East and West Usambara mountains, Tanzania, all Forest African Dormice were captured in forest; in the Eastern Cape, South Africa, these dormice are consistently captured in riverine forest dominated by South African bushwillows ( Combretum caffrum, Combretaceae ), and not in nearby. In South Africa, Forest African Dormice occupied nest boxes placed on trees at 1-1-2-7 m above the ground, and most frequently used those above 1-8 m. A separate study at the samesite in Eastern Cape, South Africa, documented that individuals were only captured in arboreal traps and never at ground level, despite placement of about equal numbers of arboreal and ground traps. Several studies indicate that habitats with a high degree of canopy cover and arboreal connectivity of trees, vines, and shrubs are preferentially selected. It has been suggested that connectivity and canopy cover may be important habitat requirements. In Volcanoes National Park, Rwanda, dormice were captured in mixed forest, a swampy area, and hagenia ( Hagenia abyssinica, Rosaceae ) forest. S. F. Lamani in 2011 radio-tracked 21 individuals and found that mean height of resting sites used for a South African population was 2-1 m and that resting sites on branches averaged higher than those located in tree cavities or nest boxes. At other South African localities outside of Great Fish River Nature Reserve, however, individuals were captured in dry thicket and among rocks, or in mixed habitats. A study carried out in Afro-montane forest in the Amathole Mountains, Eastern Cape, reported that 20% ofall Forest African Dormice were captured on the ground.
Food and Feeding. The Forest African Dormouse is omnivorous, predominantly insectivorous and carnivorous. Stomach contents have included insects and other invertebrates, seeds, leaves, stems, fruit, and occasionally small vertebrates. In KwaZulu-Natal, South Africa, stomachs contained arthropods and seeds. In a study conducted in KwaZulu-Natal, South Africa, stomachs contained mostly invertebrates, plus fruits, leaves, stems, and flowers. In Eastern Cape, South Africa, Lamani in 2014 studied food remains found in nest boxes for one year and concluded that diets predominantly consisted of arthropods, especially beetles (Coleoptera) and millipedes (family Spirostrepidae only), and fruits. Over the course of the year as resources fluctuated, arthropods overwhelmingly accounted for most of dietary intake; other percentage of food items represented varied seasonally.
Breeding. Litter sizes of Forest African Dormice are 1-6 young. Most often 3-5 embryos or young are reported. In Eastern Cape, South Africa, a promiscuous mating system in which females become receptive asynchronously was documented. Breeding activity occurs during summer months (October—February) in South Africa; in Kenya, pregnant females were collected in September—-November; and in Zambia, a pregnant female was captured in July. In South Africa, females exhibiting placental scars were captured in February, and pregnant females were collected in October, December and February. In East Africa, gestation has been estimated at c.24 days.
Activity patterns. Forest African Dormice are predominantly nocturnal. They are characterized as competent thermoregulators, maintaining body temperature at 34-38°C. They enter facultative torpor and hibernation to cope with adverse environmental conditions and conserve energy. In 1991, G. T. H. Ellison and J. D. Skinner found that cold ambient temperatures of 10°C combined with a simulated winter photoperiod of ten hours of light and 14 hours of dark, induced torpor; periods of torpor exceeded 24 hours, suggesting hibernation or deep torpor under these conditions. In 1996, P. I. Webb and Skinner documented thatif experimentally deprived of food at an ambient temperature of 25°C, individuals initially decreased activity but remained euthermic. When deprived of food at an ambient temperature of 10°C, the same individuals entered torpor with greater frequency during the day as an energy saving mechanism. A population studied in winter in Eastern Cape, South Africa by N. Mzilikazi and R. M. Baxter in 2009 and Mzilikazi and colleagues in 2012 revealed that Forest African Dormice were heterothermic at least 98% and 100% ofthe days studied, respectively. Mzilikazi and Baxter reported torpor periods of up to 96 hours. Mzilikazi and colleagues later measured a mean torpor period of 32-5 hours, with the longest torpor lasting eight days and shortest torpor lasting 2-5 hours. Forest African Dormice increased body mass by 33% prior to hibernation in this study; Mzilikazi and colleagues in 2012 also correlated longer bouts of torpor and lower body temperatures with decreases in ambient temperature as winter progressed.
Movements, Home range and Social organization. Forest African Dormice are primarily arboreal, although some populations inhabit rocky or boulder-strewn treeless montane grasslands and thus a more terrestrial. They are predominantly solitary, although cases of nest-box sharing have been recorded. In Eastern Cape, South Africa, 246 instances in which dormice were found in nest boxes, of which 156 (63-4%) contained single individuals and 90 (36:6%) were linked to aggregations ofat least two dormice. Female-biased sex ratios have been reported in some Southern African populations. According to specimen labels, in two separate instances, adult females were captured with two subadult males, indicating that offspring may stay in the nest past weaning; subadult nestlings following an adult female (up to eight individuals) were observed as they climbed and leapt across tree branches. In Volcanoes National Park, Rwanda, they were uncommon, and a trap success of 0:25% was reported. They were uncommon compared with other rodent captures in four of six montane forests in the Eastern Arc Mountains, Tanzania. At Chome Forest Reserve, they comprised only 0-:6%of small rodents. Forest African Dormice are fairly common and widespread in southern and eastern South Africa from Western Cape to Eastern Cape, Mpumalanga and Limpopo Provinces, South Africa, but uncommon in Swaziland, and in Lesotho; trap success in South Africa was 0-3-4-9%. Trap success appears higher for traps set above the ground than on the ground at some study sites, and at others moderate to equal success was reported for ground vs. arboreal placement. In Afro-montane forest near Grahamstown, South Africa, trap success was 2:3% above the ground and 0-1% on the ground, and most individuals (94:5%) were captured in traps placed more than 0-5 m above the ground. In Tanzania, Forest African Dormice were captured with equal frequency with snap traps set on and above the ground; those collected on the ground were near roots or trunks oftrees. Height off the ground combined with connectivity was a significantly correlated with trap success, but height alone was not. Natural nests have also been recorded among epiphytic ferns and mosses ofgiant forest tree, in bee hives, in swallows’ nests, and, less commonly, in human. Nesting materials recorded include grass, bark, moss or lichen, sheep’s wool, and even a banana peel; in Eastern Cape, South Africa, nests in nest boxes contained woven lichen (Usnea barbata), feathers, snake skin, and even dormouse fur. On Mount Kilimanjaro, Tanzania, a globular nest was composed ofgrass and slips of banana fronds and lined with fine grass; it was c.13 cm in diameter, with a hole in its side, and was situated c.1-5 m above the ground in a bush, according to specimen label. Home-range sizes for adult males in Eastern Cape, South Africa, averaged 3989 m?; those of adult females averaged 2091 m*. Home ranges ofadult males overlapped those of neighboring males by 62:4% and those of neighboring females by 48:2%. Males in the Eastern Cape population is not territorial and sexual receptivity in females is asynchronous; their mating system is likely promiscuous.
Status and Conservation. Classified as Least Concern on The IUCN Red List. The Forest African Dormouse has a large distribution and presumably a large population size; it occurs in several protected areas and seems to tolerate habitat alteration; and there is no evidence ofpopulations declining fast enough to qualify for inclusion in a more threatened category. Some historically recorded populations may be threatened or even extirpated, such as those in the Udzungwa Mountains, Tanzania. Nest boxes providing suitable rest sites for Forest African Dormice have been successfully used in Eastern Cape, South Africa.
Bibliography. Allen & Loveridge (1933), Ansell (1974), Avery et al. (2002), Baxter (2008), De Graaff (1981), Dippenaar et al. (1983), Ellison & Skinner (1991), Happold & Lock (2013), Holden (1996b, 2005, 2013), Hollister (1919), Kaplan (1995), Kingdon (1974), Krystufek, Haberl & Baxter (2008), Krystufek, Haberl, Baxter & Zima (2004), Lamani (2011, 2014), Lombard (2014), Lynch (1983, 1989, 1994), Madikiza (2010), Madikiza, Bertolino, Baxter & Do Linh San (2010a, 2010b), Madikiza, Bertolino & Do Linh San (2011), Mahlaba & Perrin (2003), Mzilikazi & Baxter (2009), Mzilikazi et al. (2012), Perrin & Curtis (1980), Qwede (2003), Roberts (1951), Rowe-Rowe (1986), Rowe-Rowe & Meester (1982), Skinner & Chimimba (2005), Smithers (1983), Stanley & Goodman (2011), Stanley, Goodman & Kihaule (1998), Stanley, Kihaule et al. (1998), Swanepoel (1988), Taylor (1998), Tuyisingize et al. (2013), Webb & Skinner (1996), Whittington-Jones & Brown (1999), Wirminghaus & Perrin (1992), Yalden et al. (1996).
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