A new study published in Proceedings of the Royal Society B explores how parasites impact the relationships between predator and prey populations. Researchers from Queen Mary University of London developed a novel analysis to examine how factors like parasite virulence and infection probability affect the coexistence of species in a complex predator-prey-parasite system. Parasites, often overlooked in food webs, can significantly impact the stability of these networks by affecting predator and prey populations.
The interdisciplinary team, led by Professor Christophe Eizaguirre and Dr Weini Huang, used mathematical analysis and stochastic simulations to investigate this complex system at the individual level, considering events like reproduction, death, competition, infection, and predation. The study highlighted the role of stochasticity, random fluctuations in population sizes, in determining whether species coexist or go extinct, particularly at the boundary between these states. The researchers found that the relative abundance of infected and uninfected individuals can be reversed between prey and predator populations, suggesting that direct and indirect parasite effects play a significant role in shaping infection prevalence throughout the food web.
The research emphasizes the importance of understanding how parasites influence food web dynamics for predicting the impact of environmental changes on ecosystem health and the spread of invasive diseases. The findings provide a framework for exploring the risks of certain parasites becoming invasive as they move with their hosts. This study lays a valuable foundation for understanding how these systems evolve over time and sets the stage for further research that incorporates the evolution of key parameters under the combined influence of ecological and evolutionary pressures.
By incorporating parasite dynamics into ecological models, this research has the potential to inform conservation efforts by providing a deeper understanding of how parasites can influence the resilience of ecosystems. Conservation biologists can develop more effective strategies to protect vulnerable species and maintain healthy ecosystems by taking into account the influence of parasites on predator-prey relationships. The insights from this study offer a valuable perspective on the intricate relationships within food webs and can contribute to more informed conservation decision-making.
