Up to Bat

  • Named Myotis Nimbaensis - or the Nimba Myotis - for the isolated Nimba mountain range in which they were discovered, a new bat species was first described in a Simmons et al. article published on the 13th of January this year1.

    The Nimba mountains are a mountain range in West Africa, at the borders of Guinea, Liberia, and Côte d'Ivoire. Due to the rich diversity in the area, the Guinea and Côte d'Ivoire areas of the range have been classed as a Nature Reserve by UNESCO2.

     

    A photo taken in a cave. The light source is a hole in the top left of the photo, allowing light to illuminate a triangle of the cave, revealing moss-covered rock. Photo by Tsvetoslav Hristov on Pexels.com

     

    What we know

    Myotis nimbaensis is the 14th member of the Chrysopteron subgenus, characterised in part by the colour (reddish-yellow on their back) and texture (cottony or woolly) of their fur.

    The Nimba Myotis is approximately 11cm in total length from snout to tailbone, and seemingly dimorphic, with females slightly larger than males. They have bright orange dorsal (back) fur with tricolour hairs that grade from black at the root to a white midsection and an orange tip; while their ventral fur is paler.

    Their belly is likewise tricoloured with the black fading from the fur towards the sides to become white and orange only.

    Their faces are pointed with a sloping forehead, pale skin, and orange fur; and their wing membranes are black and orange.

    The discovery of this new species brings the number of Myotis species in mainland Africa up to 11, and the number of bat species in the Nimba mountains up to 62.

     

    Taxonomy of Nimba Myotis

    Order Chiroptera

    Family: Vespertilionidae

    Subfamily: Myotinae

    Genus: Myotis
    Subgenus: 
    Chrysopteron

    Species Myotis nimbaensis / Nimba Myotis 

     

    How we know it

    Throughout January and February 2018 and March 2019, surveys were performed using harp traps in abandoned mines and natural caves. Tissue samples were taken for DNA analysis through a 3mm biopsy punch from the wing membrane - this took a small sample of tissue from the wing which was then stored in a fluid preserve.

     

    What we don't know

    We don't yet know anything about the Nimba Myotis' diet, though it appears similar to some 'gleaner' bat species (those who target prey on leaves or the ground) and may eat insects like most Myotis species. It appears to be closely related enough to M. tricolor to be included in its species complex. M. nimbaensis may be present across Guinea, Liberia, and Côte d'Ivoire, which could be determined through acoustic surveys looking for the species' unique call. Equally likely is that the species is rare or at least uncommon, with a small geographical range.

    With the current count at well over 1,400, there is a wide range of bat species, and yet there are noteworthy gaps across that range. It is likely that more new bat species will be discovered in the same area, as relatively few exploratory field studies have been taken in the Nimba range considering the wide ecological diversity of the area.

     

    Find more from the blog here.

     

    References

    1. Simmons, N. et al. A New Dichromatic Species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea. American Museum Novitates 2020, (2021).
    2. Centre, U. W. H. Mount Nimba Strict Nature Reserve. UNESCO World Heritage Centre https://whc.unesco.org/en/list/155/.