First digital characterization of the transhumance corridors through Benin used by cattle herds from Burkina Faso and associated risk scoring regarding the invasion of Rhipicephalus (Boophilus) microplus.
Background: Livestock plays a key role in the macro-economy of West Africa and provides livelihoods for millions of people. The main cattle rearing strategy in West Africa is pastoralism, including transhumance, that is a seasonal migration of cattle with their herders. This adaptive strategy aims to optimize livestock access to water and pastures. However, it can favour pathogens and vectors transboundary spread. The aim of this study was to highlight firstly, the corridors and grazing areas used by Burkina Faso transhumant cattle herds going to Benin; secondly, the characteristics of departure and arrival areas of transhumance; and thirdly, the risk score related to introduction and spread of the invasive tick species, Rhipicephalus (Boophilus) microplus, in free areas. Methods and principal findings: Therefore, GPS devices were given to 27 herders to monitor a full transhumance season between East Burkina Faso and North Benin. The analysis of 14,966 spots generated by the GPS devices revealed four main corridors and five main grazing areas used by cattle herds during transhumance. Statistical analysis of normalized difference vegetation index (NDVI), rainfall and temperature data, highlighted significant differences between departure and arrival areas. NDVI and rainfall are significantly higher in Benin than Burkina Faso, whereas temperature is significantly lower. Additionally, using biotic and abiotic parameters, a risk scoring was developed to predict the presence of Rhipicephalus (Boophilus) microplus at municipality level. Conclusions and significance: The better vegetation, temperature and rainfall conditions during the dry seasons in Benin attract cattle herds from Burkina Faso. The invasiveness and adaptability of Rhipicephalus (Boophilus) microplus added to the frequent stays of transhumant herds in infested areas suggest its potential introduction and establishment in free areas soon. Moreover, frequent intrusions of the transhumant cattle in the wildlife reserves are another risk of vectors and pathogen exchange between domestic and wild animals.