Mapping livestock movements in Sahelian Africa

Camille Jahel,Maxime Lenormand,Andrea Apolloni,Ismaila Seck,Coumba Faye,Caroline Coste,Mbargou Lo,Cecile Squarzoni Diaw,Baba Sall,Renaud Lancelot,Ibra Toure

doi:10.1038/s41598-020-65132-8

Abstract

In the dominant livestock systems of Sahelian countries herds have to move across territories. Their mobility is often a source of conflict with farmers in the areas crossed, and helps spread diseases such as Rift Valley Fever. Knowledge of the routes followed by herds is therefore core to guiding the implementation of preventive and control measures for transboundary animal diseases, land use planning and conflict management. However, the lack of quantitative data on livestock movements, together with the high temporal and spatial variability of herd movements, has so far hampered the production of fine resolution maps of animal movements. This paper proposes a general framework for mapping potential paths for livestock movements and identifying areas of high animal passage potential for those movements. The method consists in combining the information contained in livestock mobility networks with landscape connectivity, based on different mobility conductance layers. We illustrate our approach with a livestock mobility network in Senegal and Mauritania in the 2014 dry and wet seasons.

Highlights

Every year in West Africa, millions of animals move from the Sahelian semi-arid regions, where they were bred, towards southern regions looking for better grazing areas, or to be sold on consumption markets[1,2,3]
Most of the activity is concentrated in the months before the wet season (April-June), when the scarcity of rainfall impedes the regeneration of pastures and animals are moved looking for better places
It is worth noting that the wet season is characterized by a dramatic reduction of links and animal movements

Summary

Introduction

Every year in West Africa, millions of animals move from the Sahelian semi-arid regions, where they were bred, towards southern regions looking for better grazing areas, or to be sold on consumption markets[1,2,3]. Fournié et al.[9] used densities derived from human demographic data, aggregated at village level, to study the transmission of Peste des Petits Ruminants These approaches are limited to a static vision and do not enable animal movements to be explicitly taken into account. We recently witnessed the emergence of network-based approaches to study livestock movements[10,11,12] Such methods have been tested in many African countries[13,14,15,16,17,18]. We propose a way of mapping livestock movements that combines the information contained in livestock mobility networks with a landscape connectivity-based approach. We discuss the advantages and limitations of our approach

Objectives

Methods

Results

Discussion

Conclusion