Microgale cowani

Geographic Range

Microgale cowani is endemic to humid forests and associated habitats in eastern Madagascar.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Cowan's shrew tenrecs are found in more habitats than most other shrew tenrec species. They mainly inhabit lowland humid and moist montane forests of the eastern regions. They are also known from forest patches in the eastern regions of the central highlands. A few specimens have been trapped on the edges of agricultural fields. There is no evidence of M. cowani from western Madagascar. It has been suggested that M. cowani is not well adapted to the more pronounced seasonal variation typical of western Madagascar.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest
• scrub forest scrub forest

• Other Habitat Features
• agricultural agricultural

Physical Description

Microgale cowani is a small, shrew-like mammal. Because there are few collected specimens and confusion over the correct classification of those specimens, descriptions of M. cowani vary. Recent reports describe it as having a soft, short, dense pelage with sparse guard hairs. There is a wide variety of coat colors and patterns, from chocolate brown with red highlights to mousy brown with larger amounts of red. They can have a darker mid-dorsal stripe and lighter bellies. Specimens in captivity noticeably darken after molting. The tail is shorter than the body and can be bi-colored like the coat. The rostrum tapers to a point and is covered with vibrissae. The eyes are small. There is a cloacae which is the outlet for evacuating waste and the reproductive organs.

The adult tooth formula of M. cowani is I 3/3, C 1/1, P 3/3, M 3/3. The only deciduous tooth lost before the molars erupt and are fully functional is I 3/3. The replacement of the deciduous teeth happens so rapidly it is difficult to obtain specimens showing intermediate stages of tooth loss. Deciduous and adult teeth look nearly identical, requiring expertise to tell them apart. Premolars P3 and P4 are very molariform and the canine usually has a small paraconid.

All tenrecs have a lower resting metabolic rate than most other mammals. Microgale cowani has a higher resting metabolic rate, similar to tropical shrews, which is higher than most other tenrecs. The resting metabolic rate and body temperature rise for pregnant and lactating females.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

Little is known of the mating systems of Microgale cowani . When kept in captivity, male-female pairs sometimes share a nest.

Little is known about Microgale cowani reproduction. In one study 3 babies were born to captured females who had mated in the wild. Two captured specimens had 3 to 4 embryos each. Two specimens had 3 to 5 placental scars. Some specimens still had deciduous dentition so M. cowani can reproduce while still developmentally immature.

The reproduction of closely related M. dobsoni and M. talazaci were studied in the late 1960s. Three pairs of M. dobsoni were mated, resulting in one abortion and two litters of 3 young each. Four litters of M. talazaci were born in captivity, averaging 1 to 3 young. Both species started breeding after their autumn molt, around the age of 22 months. The average length of gestation was 58 to 64 days. The young started to grow hair around 12 days and opened their eyes around day 18. They grew their full coat of hair by 18 to 22 days. Around day 28 to 30 the young started following the mother at night, and were presumably weaned.

• Key Reproductive Features
• iteroparous iteroparous
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous

Not much is known about parental investment in Microgale cowani . One litter of 3 was born in captivity, but was cannibalized by the mother at 4 days of age. Like most mammals, young are likely to be cared for extensively by their female parents until they are weaned. This is supported by research on related Microgale species as well.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

No data could be found for the lifespan of Microgale cowani . Two closely related species, M. dobsoni and M. talazaci were found to live up to 6 years in captivity.

Behavior

Microgale cowani is thought to be solitary in the wild. When male and female pairs were kept together in captivity they usually shared a nest. When two males were introduced to each other in captivity they would show defensive behavior such as mouth gaping, squealing, and biting. The offensive animal would flee for cover. The males would then often ignore each other and explore the cage.

When observed in the wild, Microgale cowani behaves cryptically, using all possible sources of cover and avoiding climbing. They build nests with leaves. When washing, individuals sit on their hind legs and stroke both sides of the face simultaneously with both paws, starting behind the ears and ending at the tip of the nose. The mouth is held open for washing.

• Key Behaviors
• terricolous
• motile motile
• sedentary sedentary
• solitary solitary

Home Range

Little is known of the home range of Microgale cowani as they have not been extensively studied in a wild.

Communication and Perception

Microgale cowani has numerous vibrissae, which are used to sense surroundings. When two males are placed together they show agonistic behaviors such as mouth gaping, biting, and squealing. Due to the fact that Microgale cowani has not been extensively studied in the wild little else is known about how it communicates.

• Communication Channels
• visual visual

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

In captivity, Microgale cowani will accept orthopteran insects, ground meat, and earthworms. There is evidence of cannibalism and eating of smaller Microgale species from traps. They forage in leaf litter and among fallen branches and tree roots on the forest floor. Prey is seized with the mouth before being consumed.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• mammals
• insects
• terrestrial worms

Predation

Microgale cowani lacks obvious defenses from predators other than concealment and flight. It is possibly prey for larger reptiles, birds, and mammals. Bones of M. cowani have been found in the stomachs of Microgale pusilla , Tyto soumagnei , and Tyto alba .

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Microgale cowani is a prey species to some animals and preys on arthropods.

Economic Importance for Humans: Positive

Microgale cowani does not have an economic importance for humans. They are not captured for the pet trade and are too small to eat.

Economic Importance for Humans: Negative

Microgale cowani does not negatively affect humans.

Conservation Status

There are no known major threats to Microgale cowani . IUCN considers it to be a species of least concern as it is widely distributed, including several protected park areas, and seems to have large population numbers. It also adapts well to disturbed areas and agricultural fields.

Other Comments

The taxonomy of Microgale cowani has always been complicated. When the first specimens were collected it was not always clear what species they belonged to. As a result, M. cowani was incorrectly split into several species. The type specimen was collected by Thomas in 1882. Two taxonomic revisions have been undertaken, the first by MacPhee in 1987 and the second by Stephenson in 1995. Both MacPhee and Stephenson agree that M. crassipes is in fact the same species as M. cowani , but disagree about whether M. longirostris is its own species.

Microgale cowani along with the other Microgale species is primarily studied through trapping. In areas where M. cowani is found it tends to be trapped more often than other Microgale species. This could be due to many reasons, including it being more common, or because it has specific habits that increase its susceptibility to trapping.

Additional Links

Encyclopedia of Life

Contributors

Iris Hartshorn (author), University of Alaska Fairbanks, Link E. Olson (editor, instructor), University of Alaska Fairbanks, Tanya Dewey (editor), Animal Diversity Web.

References

Eisenberg, J., E. Gould. 1970. The Tenrecs: A Study in mammalian Behavior . Washington: Smithsonian Institution Press.

Eisenberg, J., E. Maliniak. 1985. The reproduction of the genus g. Microgale in captivity. International Zoo Yearbook , 14(1): 108-110.

Goodman, S., C. Raxworthy, C. Maminirina, L. Olson. 2006. A new species of shrew tenrec (Microgale jobihely) from northern Madagascar. Journal of Zoology , 270: 384-398.

Goodman, S., D. Rakotondravony. 2000. The effects of forest fragmentation and isolation on insectivorous small mammals (Lipotyphla) on the Central High Plateau of Madagascar. Journal of Zoology , 250: 193-200.

Goodman, S., B. Rasolonandrasana. 2001. Elevational zonation of birds, insectivores, rodents and primates on the slopes of Andrigitra Massif, Madagascar. Journal of Natural History , 35: 285-305.

Goodman, S., P. Jenkins, M. Pidgeon. 1999. Lipotyphla (Tenrecidae and Soricidae) of the Reserve Naturelle Integrale d'Andohahela, Madagascar. A floral and faunal inventory of the Reserve Naturelle Integrale d'Andringitra. Madagascar: with reference to the elevational variation. Fieldiana: zoology New Series , 94: 187-216.

Goodman, S., P. Jenkins, D. Rakotondravony. 2000. The biogeography of rodents (Rodentia: Muridae: Nesomyinae) and tenrecids (Lipotyphla: Tenrecidae) in the eastern forests of Madagascar: An assesment of altitudinal zonation along a latitudinal gradient. Memoires de la Societe de Biogeographie , 1: 127-138.

Goodman, S., P. Jenkins. 1998. The insectivores of the Reserve Speciale d'Anjanaharibe-Sud, Madagascar. A floral and faunal inventory of the Reserve Speciale d'Anjanaharibe-Sud, Madagascar: with reference to the elevational variation. Fieldiana: zoology New Series , 90: 139-161.

Jenkins, P. 2003. Microgale, Shrew Tenrecs. Pp. 1273-1278 in The Natural History of Madagascar . Chicago: The University of Chicago Press.

Jenkins, P., S. Goodman, C. Raxworthy. 1996. The Shrew Tenrecs (Microgale) (Insectivora: Tenrecidae) of the Reserve Naturelle Integrale d'Andringitra, Madagascar. A floral and faunal inventory of the eastern slopes of the Reserve Naturelle Integrale d'Andringitra. Madagascar: with reference to the elevational variation. Fieldiana: zoology New Series , 85: 191-217.

Jenkins, P. 1992. Description of a new species of Microgale (Insectivora: Tenrecidae) from eastern Madagascar. Bulletin British Museum of Natural History Zoology , 58(1): 53-59.

MacPhee, R. 1987. The Shrew Tenrecs of Madagascar: Systemic Revision and Holocene Distribution of Microgale (Tenrecidae, Insectivora). American Museum Novitates , 2889: 1-45.

Racey, P., P. Stephenson. 1996. Reproductive and energetic differentiation of the Tenrecidae of Madagascar. Biogeographie de Madagascar , 1: 307-319.

Raherisehena, M., P. Jenkins. 2008. "The IUCN Red List of Threatened Species" (On-line). Microgale cowani . Accessed November 10, 2008 at http://www.iucnredlist.org/details/40586 .

Stephenson, P. 1995. Taxonomy of shrew-tenrecs ( Microgale spp. ) from eastern and central Madagascar. Journal of Zoology , 235: 339-350.

Stephenson, P., P. Racey. 1993. Reproductive energetics of the Tenrecidae (Mammalia: Insectivora). II. The Shrew-Tenrecs Microgale spp . Physiological Zoology , 66(5): 664-685.