Related Experiment Video
Updated: Mar 6, 2026
06:25
A Real-Time Interactive System for Studying Confrontational Pursuit Behavior in Rodents
Published on: May 16, 2025
1.5K
Fitness and community consequences of avoiding multiple predators
Barbara L Peckarsky1, Angus R McIntosh2
1Department of Entomology, Cornell University, Ithaca, NY 14853, USA e-mail: BLP1@cornell.edu, , , , , , US.
Oecologia
|March 18, 2017
Summary
Multiple predators, brook trout and stoneflies, impact mayfly (Baetis bicaudatus) size and behavior. These predator interactions create a behavioral trophic cascade, increasing algal biomass, demonstrating complex ecological community dynamics.
Area of Science:
- Ecology
- Behavioral Ecology
- Aquatic Ecology
Background:
- Sublethal effects of predators on prey behavior can have cascading consequences for lower trophic levels.
- Understanding predator interactions is crucial for predicting community dynamics.
Purpose of the Study:
- To investigate the fitness and community consequences of behavioral interactions with multiple predators in a four-trophic-level system.
- To examine the single and interactive sublethal effects of brook trout and stoneflies on mayfly size at emergence and algal biomass.
Main Methods:
- An experiment was conducted in artificial stream tanks using four treatments: trout odor, stoneflies, trout odor + stoneflies, and control.
- Mayfly (Baetis bicaudatus) size at emergence and algal biomass were measured.
- Mayfly behavior (drift and feeding) was observed to determine the mechanisms of sublethal effects.
Main Results:
- Both trout odor and stoneflies reduced mayfly size at emergence, with non-additive effects observed.
- Stoneflies delayed mayfly emergence, suggesting a greater sublethal fitness cost than trout.
- Algal biomass was higher in tanks with both predators, indicating a behavioral trophic cascade.
Conclusions:
- Predator-induced behavioral changes in prey can lead to significant indirect effects on lower trophic levels.
- The presence of multiple predators can modify each other's impact on prey, a phenomenon known as interaction modification.
- Considering multiple predators and their behavioral mechanisms is essential for a comprehensive understanding of ecological communities.
Related Concept Videos
02:39Predator-Prey Interactions
22.0K
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.
22.0K
00:57Inclusive Fitness
43.0K
Most altruistic behavior—in which one animal helps another at a cost to themselves—occurs between relatives. Scientists think these altruistic behaviors evolved because they increase the inclusive fitness of the animal providing help.
43.0K
01:21Frequency-dependent Selection
24.4K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
24.4K
02:04Conservation of Small Populations
17.6K
Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less...
17.6K
00:48Optimal Foraging
14.1K
How animals obtain and eat their food is called foraging behavior. Foraging can include searching for plants and hunting for prey and depends on the species and environment.
14.1K
01:23Criticisms of the Evolutionary Perspective
408
In a study where individuals posing as strangers offered compliments and proposed casual sex to students, the responses differed significantly based on gender. Not a single woman accepted the proposal, while 70% of the men agreed. This outcome provides a useful scenario to explore through the lens of evolutionary psychology and social learning theory, highlighting the diverse perspectives on human sexual behaviors.
Evolutionary psychology provides one explanation for these findings, suggesting...
Evolutionary psychology provides one explanation for these findings, suggesting...
408