160.

Maned Rat

Lophiomys imhausi

French: Rat-a-criniere / German: Mahnenratte / Spanish: Rata de crin

Other common names: Crested Rat

Taxonomy. Lophiomys imhausi Milne-Edwards, 1867,

Somalia.

H. Milne-Edwards, in 1867, created both subfamily Lophiomyinae and genus Lophiomys to highlight original morphology of taxon mhausi. Lophiomys was generally considered unique representative of its subfamily, but its taxonomic position varied. It was placed among Cricetidae by]J. Chaline and coworkers in 1977, an opinion followed by G. G. Musser and M. D. Carleton in 2005 and by Carleton and Musser in 2013, whereas in 2015 A. Monadjem and colleagues included it in Muridae following the 2013 molecular classification of J. J. Schenk and colleagues, who found Lophiomys as basal taxon of a cladeincluding Deomyinae + Gerbillinae and sister taxon of Murinae. Monotypic.

Distribution. E Sudan, Eritrea, Ethiopia, Djibouti, N Somalia, NE Uganda, W Kenya, and an isolated record from W Tanzania.

Descriptive notes. Head-body 252-301 mm, tail 145-205 mm, ear 30-39 mm, hindfoot 34-56 mm; weight 590-920 g. The Maned Rat is Africa’s largest murid, powerfully built and with dense, long shaggy hair with gray dorsal pelage. From top of head to tail base there is a mane of black-and-white erectile coarse hairs, along which tractis a row of scent glands (these, and capacity of hairs to stock poisonous substances, complete the rodent’s defensive apparatus). Two lateral bands of white-brown to cinnamon hairs are present along flanks. Tail is moderately long (up to 80% of head-body length), is covered with long hairs, and has black-and-white tip. Skull is large and robust, with reinforced squamosal, jugal, and parietal bones which are deeper and decorated with small circular bony bumps, and other features include an oval infraorbital foramen (instead of a keyhole as inMuridae) and absence of horizontal plate of the parapterygoid fossa. These may protect eyes, masticatory muscles and brain during predator attacks, but their function remains unknown. Tympanic bullae are small and narrow. Axial skeleton bears an unusual number of thoracic (16) and lumbar vertebrae (7) compared with other murids (13 and 6, respectively). Lophiomys has only lower incisors colored yellow, upper being white, and its first molars have only six pairs of cusps as in Gerbillinae. Stomach is composed of five sections, possibly indicating unique type of gastric fermentation of cellulose (as in ruminants).

Habitat. The Maned Rat is found in mountain forest at up to 3300 m elevation in Kenya and Ethiopia, butis recorded also in dry woodland and on rocky slopes at lower elevations in Somali-Masai savannas.

Food and Feeding. Maned Rats are herbivorous and eat leaves and tender shoots. A recent study showed that they gnaw and masticate poisonous roots and bark of Acokanthera schimperi ( Apocynaceae) trees and, by slavering, spread the substance on to their highly specialized hairs in order to deliver deadly poison to predators attempting to bite or maul the rodent.

Breeding. M. J. Delany in 1975 described a litter size of 1-3. Young have some hairs at birth, and eyes open after 13 days. They are weaned after 40 days.

Activity patterns. The Maned Rat is nocturnal and semi-arboreal. It hides during daytime in hollow trees or in cavities in ground.

Movements, Home range and Social organization. The Maned Ratis generally solitary, and appears to be rare or uncommon.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Maned Rat’s disjunct distribution and rarity may justify more ecological studies in order to determine more accurately its conservation status.

Bibliography. Carleton & Musser (2013a), Chaline et al. (1977), Delany (1975), Happold (2013a), Kingdon et al. (2012), Kock & Kunzel (1999), Monadjem et al. (2015), Musser & Carleton (2005), Pearch et al. (2001), Schenk et al. (2013), Setzer (1956), Yalden et al. (1996).