Dynamics of Bats Populations: Migration and Ebola Outbreaks

Abstract There is an increasing number of human diseases that originate from animal reservoirs, zoonoses, such as the Zika and Ebola virus. In the case of Ebola, there has been significant progress during the last decade to support the hypothesis that African fruit bats are the natural reservoir of the Ebola virus. The recent Ebola epidemic occurred in Guinea (West Africa), where no Ebola virus had been recorded before. The strain of the virus has been identified as Zaire (the deadliest one) that had previously only been found in central Africa, thousands of miles away. Understanding the mechanisms for bat migration of great distances can reveal information about how Ebola spreads. Our hypothesis is that environmental pressure, i.e. the decrease of resources such as food and shelter due to seasonal alterations, challenges the population's survival and is the main driving force for bats' migration. In order to test this hypothesis, we propose a mathematical model to study the spatiotemporal dynamics of bat populations. The model splits bats' population into susceptible, infected and recovered subpopulations and takes into account the most fundamental processes that drive the disease dynamics, including how those depend on the environmental conditions and the seasonal variations. Analytical calculations and numerical simulations produce results of stable oscillations for each subpopulation due to environmental pressures. These results provide information on how Ebola outbreaks can occur in the African fruit bat population.