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, et al., 1986; Vogel, 2008)
No information regarding the mating systems of M. ruwenzorii is readily available.
As with mating systems, there is no information published regarding the general mating behavior of M. ruwenzorii. In September 1960, Rahm collected a female specimen whose two embryos had well-developed whiskers. Furthermore, two female specimens were collected in February 1984, each with a single embryo. It is possible that, due to its tropical distribution, M. ruwenzorii breeds year-round. Other than these rudimentary inferences, no other information regarding reproductive behavior in M. ruwenzorii is available. (Rahm, 1960; Stephan, et al., 1986)
The few embryos of M. ruwenzorii that have been collected indicate that parental investment may be high. It appears that M. ruwenzorii is a K-selected mammal, which indicates later maturation, low fecundity, and high parental care of offspring. (Rahm, 1960; Stephan, et al., 1986)
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 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 positive economic importance to humans from M. ruwenzorii.
There is no recorded or perceived negative economic importance to humans from M. ruwenzorii.
Tanya Dewey (editor), Animal Diversity Web.
James Smith (author), University of Alaska Fairbanks, Link Olson (editor, instructor), University of Alaska Fairbanks.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
uses sound to communicate
living in landscapes dominated by human agriculture.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
mainly lives in water that is not salty.
An animal that eats mainly insects or spiders.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
an animal that mainly eats fish
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
scrub forests develop in areas that experience dry seasons.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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1990. Micropotamogale ruwenzorii. Pp. 19 in M Nicoll, G Rathbun, eds. African Insectivora and Elephant-Shrews. Switzerland: International Union for Conservation of Nature and Natural Resources.
Benstead, J., L. Olson. 2003. Limnogale mergulus. Pp. 1267-1273 in S Goodman, J Benstead, eds. Natural History of Madagascar. Chicago: University of Chicago Press.
Kingdon, J. 1974. Micropotamogale ruwenzorii. Pp. 11-13 in J Kingdon, ed. East African Mammals, Vol. 2. London: The University of Chicago Press.
Rahm, U. 1961. Beobachtungen an der ersten in Gefangenschaft gehaltenen Mesopotamogale Ruwenzorii (Mammailia-Insectivora). Rev. Suisse de Zolologie, 68: 73-90.
Rahm, U. 1960. Note sur les specimens actuellement connus de Micropotamogale (Mesopotamogale) ruwenzorii et leur repartition. Mammalia, 24: 511-515.
Stephan, H., K. Ka Mubalamata, M. Stephan. 1986. The Brain of Micropotamogale ruwenzorii (De Witte and Frechkop, 1955). Z. Saugertierkunde, 51: 193-204.
Vogel, P. 2008. "Micropotamogale ruwenzorii" (On-line). 2008 IUCN Red List of Threatened Species. Accessed November 17, 2008 at http://www.iucnredlist.org/details/13394.