Shifts of dominant personality and spatial pattern formation due to spatially heterogeneous pollution

TL;DR

This study models how animal personality traits influence population distribution and survival in environments with spatially heterogeneous pollution, revealing shifts in dominance and pattern formation based on toxin levels.

Contribution

Introduces a prey-taxis model with nonlinear cross-diffusion to analyze animal responses to uneven pollution, providing new insights into population dynamics and spatial patterns.

Findings

Bold individuals dominate in low-toxin environments.

Shy individuals become dominant in moderate toxin regions.

High pollution leads to population extinction.

Abstract

Personality traits, such as boldness and shyness, play a significant role in shaping the survival strategies of animals. Industrial pollution has long posed serious threats to ecosystems and is typically distributed heterogeneously. However, how animals with different personalities respond to spatially heterogeneous pollution remains largely unexplored. In this study, we introduce a prey-taxis model with nonlinear cross-diffusion to examine population dynamics in such environments. The global existence of classical solutions is established by deriving initial bounds through energy estimates and improving solution regularity via heat kernel properties and a bootstrap process. Our findings reveal that behavior, population structure, and spatial distribution are heavily influenced by pollution. Bold individuals maintain a competitive advantage in pollution-free or very low-toxin environments, whereas shy individuals become dominant in regions with low to moderate toxin levels. In highly polluted areas, no populations can survive. The spatial pattern of the population is also closely tied to the distribution of toxins. Grazers tend to move along toxin gradient and exhibit periodic behavior. As toxin concentrations rise, aggregation behavior becomes increasingly pronounced across all species. Interestingly, the total population in polluted areas may initially increase when toxin levels are low to moderate, but eventually declines, leading to extinction as toxin levels continue to rise.