Micropotamogale ruwenzorii
Ruwenzori otter shrew

Ruwenzori otter shrews, Micropotamogale ruwenzorii, are found in the Ruwenzori mountain range of eastern Africa, which lies between Lake Albert and Lake Edward and to the west of Lakes Edward and Kivu. ("Encyclopaedia Britannica", 2008a; Kingdon, 1974; Vogel, 2008)

Ruwenzori otter shrews are terrestrial, semiaquatic mammals that inhabit small rivers and streams in various habitats. They are found in streams and rivers in rainforest areas, savanna edges, montane forests, and even cultivated areas, at elevations between 800 meters and 2200 meters. The temperatures in the streams and rivers that M. ruwenzorii inhabits range from 12°C to 21°C. ("Micropotamogale ruwenzorii", 1990; Kingdon, 1974; Rahm, 1960; Vogel, 2008)

The common name of M. ruwenzorii, Ruwenzori otter shrew, is a misnomer. Micropotamogale ruwenzorii is neither an otter (Lutrinae) nor a shrew (Soricidae), although they may look like large shrews. Ruwenzori otter shrews have relatively large feet for animals of their size and they are broad and webbed. Micropotamogale ruwenzorii is the only species in the genus Micropotamogale to have webbed feet. The second and third toe of the hind foot are syndactylous. At the end of the notably wide rostrum is a large pad surrounded by stout whiskers. The head and body of M. ruwenzorii is 123 mm to 200 mm and is covered by dark, dense, otter-like fur. The tail is long (100 mm to 150 mm) with course hairs along the top and bottom. Weights of M. ruwenzorii range from 75 g to 135 g. Ruwenzori otter shrew display many of the adaptations to semiaquatic carnivory reviewed by Benstead and Olson (2003). These include webbed hind feet, dense soft fur with abundant guard hairs, and a rounded tail with conspicuously longer hairs located ventrally. ("Encyclopaedia Britannica", 2008b; Benstead and Olson, 2003; Kingdon, 1974; Rahm, 1960; Rahm, 1961; Stephan, Ka Mubalamata, and Stephan, 1986; Vogel, 2008)

No information regarding lifespan of M. ruwenzorii is available.

Ruwenzori otter shrews spend most of their time in and around water, mostly streams and small rivers. They are nocturnal, with hunting, resting and grooming being the primary activities. Observations have shown that they emerge from burrows in the late evening and alternately hunt and rest. Resting is accompanied by grooming and scratching. Burrows usually consist of a tunnel dug into an earthen bank with a sleeping chamber or nest built out of dried grasses and twigs at the end. The entrances to these hollows are underwater.

Ruwenzori otter shrews swim with pectoral and pelvic strokes. They swim at the surface with the head and upper back out of the water. While they have robust, strong tails, they are not used for propulsion. Deep dives are propelled by a strong unison stroke by all four legs. Swimming sessions are typically short and they frequently return to shore to groom. (Kingdon, 1974; Rahm, 1961; Vogel, 2008)

Home Range

Home range sizes are not reported.

Ruwenzori otter shrews rely heavily on tactile sensory perception. It is thought that the presence of whiskers from even an embryonic age shows the importance of vibrissae in this species. No information on communication between individuals is available. (Kingdon, 1974; Rahm, 1961)

Micropotamogale ruwenzorii individuals feed primarily in the water or along river banks. Presumably, the stout leathery nose pad protects the nose as they forage on the bottom, using their whiskers to find prey. They eat insect larvae and worms as well as small fish, frogs, and crabs, which they grab from behind. If prey cannot be eaten quickly underwater, it is taken to land and bitten rapidly until it is subdued. (Kingdon, 1974; Rahm, 1961; Vogel, 2008)

While no information pertaining to specific predators is available, it is assumed that M. ruwenzorii is susceptible to predation by larger carnivores or aerial predators.

The range of M. ruwenzorii overlaps that of the giant otter shrew (Potamogale velox), yet there is no published evidence of their interactions. As noted above, M. ruwenzorii tends to prefer small rivers and streams. Potamogale velox, on the other hand, can be found in larger rivers and lakes. (Kingdon, 1974)

There is no recorded or perceived negative economic importance to humans from M. ruwenzorii.

There is no recorded or perceived positive economic importance to humans from M. ruwenzorii.

Micropotamogale ruwenzorii is classified as Near Threatened by the ICUN. It has a limited range and it appears that M. ruwenzorii responds negatively to increasing human densities. (Vogel, 2008)

Micropotamogale ruwenzorii was once placed in its own monotypic genus, Mesopotamogale. (Rahm, 1960; Rahm, 1961)