Dasymys montanus Thomas 1906

Dasymys montanus Thomas 1906, Ann. Mag. Nat. Hist., ser. 7, 18: 143.

Type Locality: Uganda, Ruwenzori East, Mubuku Valley, 12,500 ft (3810 m); 00°22’N, 30°00’E (W. Verheyen et al., 2003).

Vernacular Names: Ruwenzori Dasymys.

Distribution: Known only from Ruwenzori Mtns, Uganda, between 2600 and 3810 m (Kerbis Peterhans et al., 1998); a montane Western Rift endemic.

Conservation: IUCN – Vulnerable.

Discussion: Usually included in D. incomtus (Delany, 1975), but distinguished from that species by its long, fine fur that is very dark over upperparts and dark gray washed with buff on underparts; very short tail; short rostrum; low, squat cranium; wide zygomatic breadth (Thomas, 1906 a; specimens in BMNH examined by Musser). Dasymys montanus is replaced by D. incomtus at lower altitudes on the E slopes of the Ruwenzoris, and both are recorded from 2600 m, the lowest point for D. montanus and highest for D. incomtus (Kerbis Peterhans et al., 1998) . Based on multivariate analyses of craniometric traits derived from holotypes, W. Verheyen et al. (2003) suggested that montanus and medius (holotype from Ruwenzori Mtns at 1800 m) represented the same population and that both taxa were synonyms of D. incomtus . Our study of holotypes and other series, including the material reported by Kerbis Peterhans et al. (1998), indicates D. montanus to be a separate species from the lower-altitude D. incomtus ( medius).