Nimba otter shrew


The Nimba otter shrew is a dwarf otter shrew and belongs to the mammal family Potamogalidae. Otter shrews are shrew-like afrotherian mammals found in sub-Saharan Africa. They are most closely related to the tenrecs of Madagascar. This species belongs to the genus Micropotamogale, literally meaning "tiny river weasel". It is native to the Mount Nimba area which rests along the border of Liberia, Guinea, and Côte d’Ivoire in West Africa.

Description

The Nimba otter shrew is a small bodied mammal. Weighing only about 125 grams it has a body length of 6-9 inches with 1/4 to 1/3 of its body size being its tail. It has been described as a "miniature sea otter with a rat tail". Its pelage is long, hiding its ears and eyes, and almost always universally colored.

Evolution and life history

The Nimba otter shrew is classified as a member of Potamogalidae, which is related to with afrotherian tenrecs, based on morphological structures. Molecular data also support the relationship. Unfortunately, due to heavy mining operations for iron ore in the Mount Nimba area, the fossil record is all but destroyed. It is also difficult for scientists to gain access because the mountain crosses the borders of three different countries.

Ecology and behavior

The Nimba otter shrew is nocturnal and semiaquatic. It resides in soft soils around creek beds and streams.
It is a solitary creature and has only been seen with other shrews during mating seasons and when a mother is nursing newly born young.
The breeding pattern of the Nimba otter shrew is also unknown, but believed to be polygamous; as there have been no witnessed accounts of breeding in the wild and the Nimba otter shrew has not mated in captivity.

Conservation status

The IUCN had listed the Nimba otter shrew as endangered in 1990, but in 2018 the status was changed to vulnerable. The species is confined to an area less than 5,000 km² on Mount Nimba, which is currently fragmented due to mining and wetland rice agriculture. The mining operations also produce runoff into the creeks and streambeds that is highly toxic. The current population is decreasing at a rate of 1 per 10 km². Although an exact number is unknown at this time, there is believed to be less than 2500–3500 individuals in the wild; there are none in captivity. At this rate the Nimba otter shrew was predicted to be extinct between 2017 and 2020. The population within Liberia's East Nimba Nature Reserve was reported healthy in 2013. The species is also present in the Mount Nimba Strict Nature Reserve of Guinea and Côte d’Ivoire, but this reserve is adjacent to a mining operation and is not fully protected from poaching.