Animal community ecology has traditionally focused on energy and nutrients as the main ecological currencies influencing species interactions. However, water is a resource with an extremely important physiological role and dehydration can have important impacts on growth, activity, reproduction, and survival. As such, this resource may often be the most limiting in many environments or at certain times in most environments. Here we present preliminary evidence of water-mediated interactions between crickets and wolf spiders from several experiments. In one laboratory study, large adult wolf spiders (Hogna carolinensis) were acclimated to cages and given food and water ad libitum. Water was then removed from cages and consumption of juvenile house crickets (Acheta domesticus) was examined daily. These spiders consumed more crickets than spiders that had continual access to water. From another laboratory study, we present evidence of a threshold resource ratio for consumption of house crickets by wolf spiders, based on the water:dry-biomass ratio of the crickets. This suggests a trade-off between the water content of prey and water loss associated with predation. Together, these experiments suggest that rates of consumption by spiders are determined in part by the water content of their prey and thus interaction strengths between these predators and common prey items are influenced by water.
