Camera trap assessment of bushpig (Potamochoerus larvatus)-domestic animal interactions and implications for pathogen transmission in rural habitats of Madagascar

Abstract

In some rural areas of Madagascar, bushpigs (Potamochoerus larvatus) are reported to be attracted to human disturbed habitats and share the same environment with domestic animals, including pigs (Sus scrofa). Such cohabitation can facilitate the transmission of pathogens between bushpigs and other domestic animals. To assess bushpig-domestic animal interactions and their implications for pathogen transmission, 26 camera-traps were deployed for three months around 10 villages in two separate regions of western Madagascar. The camera-traps were positioned at animal attraction sites: trophic resources, resting areas, and water points, and captured 17,804 images. No direct interactions (simultaneous presence) between bushpigs and domestic species were observed after analysis of 2678 trap nights. However, 44 indirect interactions (non-simultaneous presence) were recorded. The median critical time window (CTW), calculated as the time interval between the consecutive presence of bushpigs and some domestic species, was 646 min [34-1412 min]) for pigs, 672 min for cats [range 44-886 min], and 690 min for cattle [range 584-765 min]. Such CTW estimates are shorter than the average survival rate of several infectious pathogens potentially present in the environment, including African swine fever virus, Mycobacterium bovis, and Toxoplasma gondii. Factors such as proximity to water sources and protected areas statistically increased the chances of these interactions. Our research provided novel information on the level of interaction between bushpigs and other domestic animals in anthropized rural areas and which can be used to design and implement strategies to mitigate the risk of pathogen spread at the wildlife/livestock/human interface.

Keywords: Ecology; Madagascar; Pathogens; Spill-over; Suidae; Sympatry.

Fig. 1

Map of field sites for camera trap survey in the Menabe Region.

Fig. 2

Map of field sites for camera trap survey in the Boeny Region.

Fig. 3

Averages of the trapping success (and standard errors) for the main species detected across the different types of deployment sites in the Boeny and Menabe Regions.

Fig. 4

Density estimates of temporal activity displayed by BP and DP in the Boeny and Menabe Regions. Activity overlap between species is represented by the gray shaded area between lines. Delta Δ₄ is the most appropriate overlap coefficient.

Fig. 5

Temporal overlap analysis of visit intervals and pathogen persistence. Violin plots show the distribution of intervals (hours) between visits by BP and DP at shared sites, compared to environmental survival times of [24], Toxoplasma gondii [46], Mycobacterium bovis [49], and the observed CTW.