Consistent temperature dependence of functional response parameters and their use in predicting population abundance

Area of Science:

• Ecology
• Climate Change Biology
• Ecological Modeling

Background:

• Global warming poses a significant threat to population persistence.
• Increased metabolic demands due to warming can intensify species interactions, potentially destabilizing food webs.
• Understanding temperature-dependent consumer-resource interactions is crucial for predicting ecological responses to climate change.

Purpose of the Study:

• To quantify the temperature dependence of predator-prey feeding interactions.
• To assess how temperature influences attack rates, energetic efficiency, and population abundance.
• To evaluate the predictive power of energetic efficiency for field population abundance across different predator types.

Main Methods:

• Investigated feeding interactions between predator-prey pairs in controlled laboratory temperature chambers.
• Studied predator-prey interactions in naturally heated stream ecosystems.
• Measured attack rates, metabolic rates, and estimated energetic efficiency and population abundance under varying temperatures.

Main Results:

• Consistent temperature dependence of attack rates was observed across experimental settings.
• The magnitude and activation energy of attack rate varied among predators based on mobility and foraging mode.
• Energetic efficiency accurately predicted field abundance for a mobile predator but not for a sedentary predator.

Conclusions:

• Temperature effects on population abundance are contingent on whether populations are limited by energy intake or interspecific interactions.
• Reconciling laboratory and field data on functional responses enhances predictions of warming impacts on ecosystems.
• Predator mobility and foraging strategy significantly mediate responses to warming-induced changes in ecological interactions.