Dispersal-induced survival of predators in metacommunities due to transient chaos

TL;DR

This study demonstrates that limited, strategic dispersal in ecological networks can induce transient chaos, preventing predator extinction and promoting biodiversity in fragmented habitats.

Contribution

It reveals a novel mechanism where asymmetric dispersal and transient chaos sustain predator populations, contrasting with classical rescue effects.

Findings

Asymmetric dispersal prevents predator extinction across broad ranges.

Small-world networks with few long-range links can sustain chaotic oscillations.

Transient chaos induced by dispersal maintains biodiversity in fragmented landscapes.

Abstract

Dispersal networks critically shape the fate of ecological communities, yet the mechanisms linking connectivity and persistence remain poorly understood. We show that an interplay between asymmetric dispersal and asynchronous dynamics across patches in a dispersal network can prevent predator extinction across broad dispersal ranges, even in identical environments in which synchrony usually drives ecosystems to collapse. Unlike classical rescue effects based on environmental heterogeneity or equilibrium states, this mechanism emerges from non-equilibrium dynamics, specifically from transient chaotic dynamics. Dispersal coupling perturbs local trajectories in patches facing extinction and reinforce chaotic motion, thereby sustaining chaotic oscillations indefinitely. Strikingly, only minimal connectivity is required: small-world networks with a few long-range links suffice to rescue predator populations. These findings reveal a counterintuitive principle that limited, well-placed connectivity can harness chaos to maintain biodiversity in fragmented landscapes.