Data from: Determining the optimal movement strategies in environments with heterogeneously distributed resources and toxicants

Environmental stress forces populations to move away from oppressive
regions and look for desirable environments. Different species can respond
to the same spatial distributions of resource and toxicant with distinct
movement strategies. However, the optimal behavioral strategy may differ
when a resource and a stressor occur simultaneously or if they distribute
in different patterns. We compared the total abundance of two strains of
Caenorhabditis elegans with different locomotion speeds as they forage in
various spatial distributions of resource and toxicant. Informed by the
experimental observations, we proposed a new two-state population model,
wherein nutrient up-take and reproduction are modeled separately, as
driven by the spatial distribution of resource and toxicant. We found that
fast movers had an advantage when either the toxicant coverage or the
overlap between toxicant and resource is increased. Also, to assess the
effectiveness of designing refuges to conserve species in stressful cases,
we compared different preferences of locations of refuge area according to
movement strategies. Our mathematical model explained that fast movement
enables individuals to consume resources at one location and reproduce at
a separate location to avoid the toxicant-induced reduction in
reproduction rate, which underlined its observed advantage in certain
experimental settings. This work provided a better model to predict how
species with different movement strategies respond to environmental
stressors in natural systems.