The conservation status of a poorly known range-restricted mammal, the Nimba otter-shrewMicropotamogale lamottei

Abstract

We have a poor understanding of the ecology of many African small mammals due to a lack of basic research. This has important conservation implications, particularly for range-restricted species in tropical regions. In this study, we provide new insight into the distribution and ecology of one such species, the Nimba otter-shrew (Micropotamogale lamottei Heim de Balsac 1954). We apply niche and occupancy modeling to inform on the range and habitat use of this semi-aquatic species. We estimate that its global range [extent of occurrence (EOO)] is 14,725 km2. Using occupancy modeling, we show that mining has a direct impact on the occurrence of this species. We also provide preliminary observations of its movements through radio-tracking. Using maximum entropy (Maxent) modeling, we identify the North Lorma National Forest and the Wonegizi range (northern Liberia) that appear suitable for this species, but where it has not yet been recorded. We suggest that the Nimba otter-shrew has a global distribution centered on the Mount Nimba region, straddling the borders of Liberia, Guinea and Côte d’Ivoire, and that it requires urgent conservation attention to ensure its long-term persistence. Finally, we provide evidence to support an uplisting of its IUCN Red List conservation status to Vulnerable.

Small mammals of a West African hotspot, the Ziama-Wonegizi-Wologizi transfrontier forest landscape

“…Finally, we recorded the presence of the globally "Vulnerable" otter-shrew M. lamottei in Wologizi (IUCN 2020). This represents the third locality in Liberia, and the fourth globally for this threatened and highly rangerestricted species (Monadjem et al 2019a). This species was previously recorded from Ziama (Vogel 1983).…”

“…A single female was captured from Lisco (Liberia). This species has been previously recorded from the Liberian side of Mt Nimba with a single record from Sérédou in the Ziama forest (Guinea) (Coe 1975;Decher et al 2016;Monadjem et al 2019a;Vogel 1983). This species is restricted to the upland areas surrounding the border zone between Guinea and Liberia centred on Mt.…”

“…We captured otter-shrews using funnel traps made of mesh wire (Monadjem et al 2019a). We deployed 50-100 funnel traps along small rivers and streams, with traps remaining active for four consecutive nights.…”

“…To illustrate this point, only seven species of bats have been documented in Wologizi forest (Monadjem and Fahr 2007). However, some important small mammals have been reported from this region including the threatened Nimba otter-shrew (M. lamottei) and the poorly known Ziama horseshoe bat (R. ziama) both of which are known from Ziama forest, and the latter also from Wonegizi forest (Decher et al 2016;Fahr et al 2002;Heim de Balsac 1954;Monadjem et al 2019a).…”