Range expansion of the invasive house mouse Mus musculus domesticus in Senegal, West Africa: a synthesis of trapping data over three decades, 1983–2014

Abstract

The worldwide intensification of human‐associated exchanges favours the multiplication of biological invasions. Among mammals, rodent species, including the house mouse Mus musculus, are identified as major invaders with profound impacts on native biodiversity, human health and activities. Though contemporary rodent invasions are described on several islands, there are few data describing ongoing house mouse invasions in continental areas. We first outline the known picture of the distribution of the house mouse in Africa. We then describe the ongoing range expansion of the house mouse in Senegal, in order to update its distribution area, assess the location of the invasion front, describe the spatio‐temporal dynamics of the invasion at the country scale and evaluate its impact on native small mammal communities. We briefly review the worldwide status of the house mouse, with special focus on its situation in Africa. Focusing on Senegal, we then use historical records and a large body of spatio‐temporal indoor trapping data obtained from small mammal communities over the last 30 years to analyse the invasion dynamics of the subspecies at the scale of the country. The geographic range of the invasive house mouse is surprisingly poorly known in Africa. In Senegal, we document a large range expansion of the subspecies in human settlements over the whole country within the last 30 years. The invasion is still ongoing further east and south within the country, and has major consequences for small mammal communities and thus probably for risks associated with zoonotic diseases.

Contemporary variations of immune responsiveness during range expansion of two invasive rodents in Senegal

“…Because environmental variations may drive differences in immune responses between rodent populations independently of the invasion status categories, we described relevant climatic and commensal habitat parameters for all sampling sites and included them in further statistical analyses. We focused on these factors and did not include vegetation information because house mice and black rats are strictly commensal in Senegal, and because both invasive species expand their range through human trade and transport rather than by individual dispersal in the wild (Dalecky et al ). Means and standard deviations of climatic data collected between 1997 and 2012 were used (data available on < http://www.ncdc.noaa.gov/cdo-web/datasets > for temperatures, and < http://richardis.univ-paris1.fr/precip/rainser1.html > for rainfall with GPCP‐1DD as the source of data).…”

“…living in/around human dwellings/man‐made structures) and are worldwide significant invasive species (Global Invasive Species Database – < http://www.issg.org/database/ >). Complete syntheses reporting description of their current invasion histories in Senegal (including data of historical inventories, molecular analyses and ecological longitudinal surveys) are provided elsewhere (Konecny et al , Dalecky et al ). Briefly, both species originated from Asia and have expanded their distribution range worldwide, making use of human migration to colonize all the continents.…”

“…Their distribution currently covers much of north and central Senegal for M. m. domesticus and south and central Senegal for R. rattus . Recent longitudinal surveys (Granjon and Duplantier , Dalecky et al ) have documented how the ongoing expansion of both species has resulted in the extirpation of native rodents (mostly Mastomys erythroleucus and Mastomys natalensis ) from commensal habitats, these latter species being now found almost only in villages at the invasion front and in non‐invaded areas.…”

Emergence of Wesselsbron virus among black rat and humans in Eastern Senegal in 2013

“…Briefly, traps (wire-mesh locally made and folding aluminium Sherman© traps) were set inside buildings for trapping sessions of one to six consecutive days with peanut butter as bait [6]. One of each type of traps was set per room and inspected for captures each morning.…”

Interplay between historical and current features of the cityscape in shaping the genetic structure of the house mouse (Mus musculus domesticus) in Dakar (Senegal, West Africa)

“…Vegetation the more recent development of high-standing residential areas and 6) areas mainly devoted to commercial and industrial activities that have been expanding from the harbor since the first European settlement. As highly vegetated areas may constitute a very unfavorable habitat (desert resource, Combs et al, 2018b) for the house mouse, which is strictly synanthropic in Senegal (Dalecky et al, 2015), we also extracted information on vegetation occurrence to describe the cityscape of Dakar (Supplementary material, section 1, Fig. S1.1).…”