Disease
transmission can be strongly influenced by the manner in which conspecifics are
connected across a landscape and the effects of land use upon these dynamics.
In northern Botswana, the territorial and group-living banded mongoose (Mungos
mungo) lives across urban and natural landscapes and is infected with a
novel Mycobacterium tuberculosis complex pathogen, M. mungi.
Using microsatellite markers amplified from DNA derived from banded mongoose
fecal and tissue samples (n = 168), we evaluated population genetic
structure, individual dispersal, and gene flow for 12 troops. Genetic structure
was detectable and moderately strong across groups (FST =
0.086), with K = 7 being the best-supported number of genetic clusters.
Indications of admixture in certain troops suggest formation of new groups
through recent fusion events. Differentiation was higher for troops inhabiting
natural (FST = areas 0.102) than for troops in urban
landscapes (FST = 0.081). While this suggests increased
levels of gene flow between urban-dwelling troops, the inclusion of a smaller
number of study troops from natural land types may have influenced these
findings. Of those individuals confirmed infected with M. mungi, the
majority (73%, n = 11) were
assigned to their natal group consistent with previous observations linking
lower levels of dispersal with infection. Twenty-one probable dispersing
individuals were identified, with the all suspected migrants originating from
troops within the urban landscape. Findings suggest that urbanized landscapes
may increase both gene flow and dispersal behavior with a concomitant increase
in the risk of pathogen spread. As urban
landscapes expand, there is an increasing need to understand how land use and
pathogen infection may change wildlife behavior and disease transmission
potential.
Funding
Support for this project was provided by the National Science Foundation Ecology and Evolution of Infectious Disease program (grant #479367).