Competition avoidance: The role of spatial and temporal niche partitioning for desert scorpions

Background/Question/Methods

The effects of competition on a species can be reduced through niche partitioning. Competition among scorpions may be particularly strong given the high levels of intraguild predation (IGP) common within the group. We investigated the spatial distribution and temporal activity of three species of scorpions along an environmental gradient in northern Utah, with the goal of examining how scorpions may manage interspecific competition through niche differentiation.

Results/Conclusions

The scorpions Anuroctonus phaiodactylus, Paravaejovis confusus, and Paruroctonus boreus were found to differ in both their relative abundance on different soil types, and their activity through time: A. phaiodactylus and P. confusus were each most abundant on two different sandy soils during warmer periods, while P. boreus was in more marginal habitats and often active during cooler weather and later into the night, strategies that may have reduced the effects of competition from the other two species. Its complete absence in apparently suitable habitat occupied by the other two species, combined with its activity in suboptimal periods, suggests the possibility of competitive exclusion and operation of both spatial and temporal mechanisms of competition avoidance.