Foraging behaviour and patch size distribution jointly determine population dynamics in fragmented landscapes

Area of Science:

• Ecology
• Population Dynamics
• Biodiversity

Background:

• Habitat fragmentation is a major threat to animal populations.
• The effects of fragmentation per se on population dynamics and ecosystem stability are not well understood.

Purpose of the Study:

• Investigate how fragmentation and optimal foraging behavior interplay to affect predator-prey interactions and ecosystem stability.
• Analyze the impact of different predator dispersal strategies on coexistence in fragmented landscapes.

Main Methods:

• Utilized a spatially explicit predator-prey model.
• Simulated predator dispersal using Lévy random walks.
• Examined the influence of fragmentation degree and Lévy exponent on coexistence probabilities.

Main Results:

• Coexistence probabilities are jointly determined by the Lévy exponent and fragmentation degree.
• Brownian and ballistic predators go extinct in highly fragmented landscapes; only scale-free predators can coexist.
• Predation leads to irreversible habitat loss in fragmented landscapes due to prey overexploitation.
• Predator dispersal can reduce, but not eliminate, habitat loss.

Conclusions:

• Integrating optimal foraging theory with population and landscape ecology is crucial for assessing fragmentation impacts.
• Scale-free predator behavior is key for species persistence in fragmented ecosystems.
• Fragmentation significantly alters predator-prey dynamics and ecosystem stability.