Warming effects on consumption and intraspecific interference competition depend on predator metabolism

Area of Science:

• Ecology
• Animal Behavior
• Environmental Science

Background:

• Intraspecific interference competition is crucial for community stability.
• The effect of environmental temperature on interference competition is poorly understood.
• Ground beetles exhibit varying body sizes and ecological roles.

Purpose of the Study:

• To investigate the impact of environmental temperature on intraspecific interference competition in two ground beetle species.
• To determine how body size influences the response of interference competition to temperature changes.
• To explore the relationship between metabolic rates and interference competition under different temperatures.

Main Methods:

• Functional response experiments were conducted on two ground beetle species: Pterostichus melanarius and Poecilus versicolor.
• Experiments were replicated across four predator densities and two temperature conditions.
• Predator movement, encounter rates, and interference behaviors were quantified.

Main Results:

• Increasing temperature enhanced interference competition in the larger species, P. melanarius.
• The smaller species, P. versicolor, showed reduced interference with increasing temperature.
• Species-specific metabolic rate responses to temperature explained the observed differences in interference behavior.

Conclusions:

• Environmental temperature has complex, species-specific effects on intraspecific interference competition.
• Metabolic rate sensitivity to temperature is a key factor mediating interference competition.
• Generalizations about warming effects on competition must consider species' physiological responses.