Hybomys (Hybomys) lunaris (Thomas 1906)

[Hybomys (Hybomys)] lunaris (Thomas 1906), Ann. Mag. Nat. Hist., ser. 7, 18: 145.

Type Locality: Uganda, Ruwenzori East, Mubuku Valley, 6000 ft (1830 m).

Vernacular Names: Ruwenzori Hybomys.

Distribution: Ruwenzori Mtns, W Uganda.

Conservation: IUCN – Lower Risk (lc).

Discussion: Subgenus Hybomys . Originally described as a subspecies of H. univittatus by Thomas, lunaris was raised to a species based upon chromosomal traits (Verheyen and Van der Straeten, 1985) and morphometric analyses (Van der Straeten, 1985; Van der Straeten et al., 1986). Van der Straeten et al. (1986) identified the species as occurring in NE and E Dem. Rep. Congo, W Uganda, and Rwanda, but their samples from these areas are not representative of true lunaris, a morphology so far known only from the Ruwenzori Mtns. Verheyen and Van der Straeten (1985) documented 2n = 48 for a Rwandan sample they labeled H. lunaris, which contrasted with 2n = 44 from their Cameroon material they identified as H. univittatus . However, Carleton and Robbins (1985) recorded a 2n = 48 from northwest of Dongila, the type locality of H. univittatus and considered that karyotype typical of the latter. Carleton and Robbins (1985:985) explained that " Verheyen and Van der Straeten (1985) assumed that lunaris applied to their Rwandan locality because it was the geographically closest epithet available for easternmost populations of Hybomys . Thomas (1906) described lunaris from an intermediate elevation on the northeastern slope of Mt Ruwenzori, the Mubuku Valley, Uganda, and his diagnosis clearly depicts a small, delicate form of Hybomys . In fact, our two Ugandan examples [USNM 526765 and 526766] … from Kanyawara, a place near the type-locality, precisely fit Thomas’ description in their coloration, delicate skull, and small size.... These two specimens contrast sharply with the larger robust skulls seen in our examples from Uwinka, Rwanda [USNM 340830-340834], the same locality where Verheyen and Van der Straeten obtained karyotypic preparations. Morphologically and chromosomally, the karyotyped Hybomys from Gabon, Rwanda, and Dem. Rep. Congo, reported herein and by Verheyen and Van der Straeten (1985), conform closely and appear to represent but one species, univittatus ." Carleton and Robbins (1985) suggested that lunaris proper is a valid species, and Kerbis Peterhans et al. (1998) restricted H. lunaris to the Ruwenzori Mtns. The " lunaris " populations identified by Verheyen and Van der Straeten (1985; also Van der Straeten et al., 1986) may prove to be a new species, but their separation from H. badius and H. univittatus will require concerted revision and critical association of distinctive morphologies to type specimens.