The Biotic Correlates of Habitat Selection
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Due to trade-offs between attraction and repugnance, soil arthropods can
apparently develop spatially distributed density-dependent mechanisms.
These are probably also related to weather conditions (Paris 1963) and regulate population sizes within microsites. The formation of small aggregations
in favourable micro sites results from attraction, while a density-dependent
rate of dispersion increases food searching efficiency and protects resources
from overexploitation and contamination. It also diminishes the searching
efficiency of predators. Specialisation allows animals to partition food
resources in more or less homogeneous sheltered sites, while density-dependent behaviour favours the exploitation of food. The overall conclusion is that
arthropods with highly specialised diets may achieve optimal habitat selection at a local population level due to their capability for aggregating on food
items coupled with "Allee-type" density-dependent demography.