Abstract
Urbanization processes are taking place at a very high rate, especially
in Africa, these. At the same time, a number of small mammal species, be
they native of invasive, take advantage of these human-induced habitat
modifications. They represent commensal communities of organisms that
cause a number of inconveniences to humans, including as potential
reservoirs of zoonotic diseases. We studied via live trapping and
habitat characterization such commensal small mammal communities in
small villages to large cities of Senegal, to try understand how the
species share this particular space. Seven major species were recorded,
with exotic invasive house mice (Mus musculus ) and black rats
(Rattus rattus ) dominating in numbers. The shrew Crocidura
olivieri appeared as the main and more widespread native species, while
native rodent species (Mastomys natalensis , M.
erythroleucus , Arvicanthis niloticus and Praomys daltoni )
were less abundant and/or more localized. Habitat preferences, compared
between species in terms of room types and characteristics, showed
differences between house mice, black rats and M. natalensisespecially. Niche (habitat component) breadth and overlap were measured.
Among invasive species, the house mouse showed a larger niche breadth
than the black rat, and overall, all species displayed high overlap
values. Co-occurrence patterns were studied at the locality and local
scales. The latter show cases of aggregation (between the black rat and
native species, for instance) and of segregation (as between the house
mouse and the black rat in Tambacounda, or between the black rat andM. natalensis in Kédougou). While updating information on
commensal small mammal distribution in Senegal, a country submitted to a
dynamic process of invasion by the black rat and the house mouse, we
bring original information on how species occupy and share the commensal
space, and make predictions on the evolution of these communities in a
period of ever-accelerating global changes.
Keywords: Community ecology; co-occurrence; rodents; shrews;
West Africa