22.

Congo Forest Rat

Deomys ferrugineus

French: Déomys roux / German: Kongo-Waldmaus / Spanish: Rata de bosque de Congo

Other common names: Rusty Link Rat

Taxonomy. Deomys ferrugineus Thomas, 1888,

“Lower Congo.”

R. Lydekker in 1889 described Deomyinae as a separate subfamily for the monotypic Deomys and noted its unique intermediate position between Cricetidae and Murinae. This position was also noted in the initial description by O. Thomas, but in 1897, he put Deomys in Dendromurinae where it remained until 1990, with the exception of|. R. Ellerman in 1941 who retained Deomyinae for Deomys alone because of its unique zygomatic plate and infraorbital foramen disposition. Different molecular phylogenetic analyses including nDNA and mtDNA sequences and total DNA-DNA hybridization since 2001 have suggested that Deomys is not a Dendromurinae but a sister taxon of Acomys, Uranomys, and Lophuromys . Two subspecies recognized.

Subspecies and Distribution.

D.f.ferrugineusThomas,1888—LowerCongo.

D. f. christyi Thomas, 1915 — known only from the type locality in Poko, Uelle River, N DR Congo.

Also present in Cameroon, Equatorial Guinea, Gabon, Uganda, Rwanda,Burundi, and NW Tanzania, but subspecies involved not known.

Descriptive notes. Head—body 109-150 mm, tail 159-202 mm, ear 23-27 mm, hindfoot 33-38 mm; weight 40-77 g. Dorsum of the Congo Forest Rat is reddish brown, more or less dark with black hairs on back and rump in some populations; underpart is pure white. Tail is ¢.140% of head-body length, with little tuft of hairs at tip. Feet are very long and narrow, and first and fifth digits are very small. Skull is long and narrow, especially rostrum region and molars rows that have a dental pattern reminiscent of Dendromurinae (i.e. presence of only a t4 cusp and absence of tl on M'). Females have two pairs of mammae.

Habitat. Lowland primary forest with low and sparse understory, low density of saplings, and closed canopy. Congo Forest Rats tend to avoid disturbed habitats. In Gabon, clearings with tree-fall and dead woody debris arefavored by Congo Forest Rats, and they are frequently trapped along small streams or in swamp forest. Nests are made with leaves and vegetation in holes at bases oftrees.

Food and Feeding. Diet includes arthropods (ants, termites, insects, and millipedes) and vegetation. The CongoForest Rat also eatsearthworms, snails, and even small vertebrates. It forages for prey in the soil.

Breeding. Congo Forest Rats reproduce year-round. Females can become pregnant just after giving birth and can have 1-6 offspring each month or so, after gestation of 4-6 weeks. Young are precocial, with open eyes at birth. They eat solid food on their first day, are nursed for c.2 weeks, and are mature at 2-3 months.

Activity patterns. The CongoForest Rat is crepuscular and nocturnal. It is strictly terrestrial but can paddle with its long feet in shallow water.

Movements, Home range and Social organization. The Congo Forest Rat reportedly lives in small family groups and might be territorial. It is found in natural and humanaltered habitats (primary forest and fallow land) in the region of Kisangani (DR Congo). Individuals moved a maximum of 89 m in primary forest and 46 m in fallow land. Average movements of males and females were shorter in fallow land (males 24-4 m and females 9-7 m) than in primary forest (males 37 m and females 30 m). No marked individuals from trapping grids in fallow land were captured in primary rainforest and vice versa. Survival was slightly longer in primary forest compared with fallow land, which might have been due to higher availabilities of termites and other insects. In Gabon, home ranges averaged 5500 m? for males and 2533 m” for females.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Congo Forest Rat is common in many protected areas.

Bibliography. Denys et al. (1995), Dieterlen (1985b, 1986), Dubost (1968), Duplantier (1982, 1989), Eggleton et al. (2002), Ellerman (1941), Genest-Villard (1980), Katuala et al. (2008), Kennis et al. (2012), Kerbis Peterhans & Patterson (1995), Lydekker (1889), Malcolm & Ray (2000), Michaux et al. (2001), Rahm (1972), Ray (1996), Ray & Malcolm (2013a, 2013b), Rosevear (1969), Schenk et al. (2013), Thomas (1897a).