The Bamenda pygmy shrew (''Sylvisorex silvanorum'') is a terrestrial

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...

described by Hutterer, Riegert and Sedláček in 2009. It was first discovered during a

Museum Koenig The Museum Koenig Bonn, formerly Zoological Research Museum Alexander Koenig (German: ''Zoologisches Forschungsmuseum Alexander Koenig'', abbreviated ZFMK), is a natural history museum and zoological research institution in Bonn, Germany. The mus ...

expedition to the Bamenda Highlands of

Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...

in 1974, but was not recorded again until 2001, when partial skull remnants were located in the pellets of the endemic

African grass owl The African grass owl or simply grass owl (''Tyto capensis'') is a species of owl in the barn owl family, Tytonidae. Description The African grass owl resembles the Western barn owl, barn owl and has a heart shaped whitish-cream facial disc, w ...

Description

A relatively small species, the Bamenda pygmy shrew measures 5.2 centimetres in body length, with a tail length of around 4.4 centimetres. The shrew is primarily dark brown in colour, with a slightly lighter patch on the stomach. The species is distinguishable from other

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

varieties due to its comparatively reduced proportions and diminutive

cranial Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Thi ...

size. It is possible that the shrew is

sister taxa In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

with the

Volcano shrew The volcano shrew (''Sylvisorex vulcanorum'') is a species of mammal in the family Soricidae found in the high-altitude rainforest of Burundi, eastern Democratic Republic of the Congo, Rwanda, and Uganda. Its natural habitats are subtropical or ...

, found in the

Albertine Rift The Albertine Rift is the western branch of the East African Rift, covering parts of Uganda, the Democratic Republic of the Congo (DRC), Rwanda, Burundi and Tanzania. It extends from the northern end of Lake Albert to the southern end of Lake Tan ...

, as the pair share numerous characteristics and features.

Distribution and habitat

The species are known to be endemic to a pair of

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

craters found near

Bamenda Bamenda, also known as Abakwa and Mankon Town, is a city in northwestern Cameroon and capital of the Northwest Region (Cameroon), Northwest Region. The city has a population of about six hundred thousand people and is located north-west of the C ...

, known as the Bafut Ngemba Forest Reserve. The lower crater contains the remnants of a past lake, while the previously flooded upper crater contains a wet grassland. The

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

forests surrounding the former appears to be the primary habitat, in addition to adjacent bamboo enclaves and grasslands. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

of the shrew was located in dense undergrowth near a stream, suggesting that the population nearby is likely to greater in prevalence in this specific locality.

References

{{Taxonbar, from=Q21317874 Endemic fauna of Cameroon

Bamenda pygmy shrew The Bamenda pygmy shrew (''Sylvisorex silvanorum'') is a terrestrial species of shrew described by Hutterer, Riegert and Sedláček in 2009. It was first discovered during a Museum Koenig expedition to the Bamenda Highlands of Cameroon in 1974, ...

Mammals of Cameroon