Abstract:
Bushpigs (Potamochoerus larvatus) are considered a nuisance to farmers because of
their crop raiding habits. Through their incursions into farmlands, they may interact with
free-ranging domestic pigs and potentially cause transmission of infectious diseases
such as African Swine Fever (ASF). The role of the bushpig in the epidemiology of ASF
is poorly known and one of the gaps of knowledge is precisely the nature of interaction
between bushpigs and domestic pigs. Thus, in this study, we investigated the frequency
of bushpig visits to crop fields in rural communities where ASF is endemic, at the edge of
a wildlife protected area in northwestern Uganda, to better understand the potential for
interaction and disease transmission. We used three methods (questionnaires, camera
traps, and observations for tracks) to assess bushpig visits to farmland. These methods
were implemented concurrently in 28 farms during rainy and dry seasons. The results
obtained by each of the three methods were analyzed by generalized linear mixed
models. Potential risk factors including crop type, season, and landscape characteristics
related to bushpig ecology were tested as explanatory variables. A generalized linear
model and the Kendall test were used to compare the results and consistency of the
frequency values obtained by the three methods. A high percentage (75%) of interviewed
farmers reported visits from bushpigs in 29.6% of assessed crops (n = 145), and a
frequency of 0.014 +/−0.05 visits per night was obtained through camera-trapping.
Bushpig tracks were detected in 36% of sessions of observation. Cassava (Manihot
esculenta) and groundnut (Arachis hypogaea L.) crop fields were the most visited, and
these visits were more common during the rainy than the dry season. Distances from
crop sites to the boundary of the protected area and to the river also influenced visit frequency. Camera-trapping was the least sensitive method while questionnaires and
track observations presented consistent and complementary results to characterize spatial and temporal visits of bushpig into the crop fields. Evidence from our study shows
that when used in combination, these methods can provide useful data to improve
our understanding of the interactions between bushpigs and domestic pigs at the
wildlife-domestic interface.
