Related Experiment Video
Updated: May 26, 2026
06:25
A Real-Time Interactive System for Studying Confrontational Pursuit Behavior in Rodents
Published on: May 16, 2025
Non-interactive multiple predator effects on tadpole survival.
Oscar Ramos1, Josh Van Buskirk
1Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland. o.j.ramos.real@gmail.com
Oecologia
|December 14, 2011
Summary
Predator interactions affect tadpole survival. Dragonfly larvae (Anax imperator) showed interference, while newts (Triturus alpestris) and backswimmers (Notonecta glauca) had independent effects, aiding community modeling.
Area of Science:
- Ecology
- Predator-Prey Dynamics
- Community Ecology
Background:
- Understanding interspecific and intraspecific predator interactions is crucial for predicting prey survival.
- Predator density and species composition can significantly influence ecological community structure.
Purpose of the Study:
- To quantify the effects of three predator species on tadpole survival.
- To investigate predator interference and density-dependent effects within and among species.
Main Methods:
- Short-term predation experiments were conducted using tadpoles (Rana temporaria) as prey.
- Three predator species were used: dragonfly larvae (Anax imperator), newts (Triturus alpestris), and backswimmers (Notonecta glauca).
- Predator density and pairwise species combinations were manipulated to assess impacts on prey mortality.
Main Results:
- Newt and backswimmer predation rates were independent of predator density.
- Dragonfly larvae exhibited density-dependent predation, with reduced rates at higher densities.
- The presence of other predator species did not alter the impact of any single predator species.
Conclusions:
- The predator system is characterized by interference among dragonfly larvae but independent effects between predator species.
- Observed interactions align with the natural history of the species involved.
- Findings support the predictability of community dynamics through modeling interacting species assemblages.
Related Concept Videos
02:39Predator-Prey Interactions
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.
01:21Frequency-dependent Selection
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.
01:28Microbial Interactions: Predation
Microbial predation refers to the process by which one microorganism kills and consumes another to obtain nutrients and energy. It encompasses both bacterial and protozoan predators. This interaction plays a crucial role in shaping microbial communities and regulating nutrient cycling.Bacterial Predators: Epibiotic vs. EndobioticBacterial predators are classified based on their mode of attack as either epibiotic or endobiotic. Epibiotic predators, such as Vampirococcus, attach to the surface of...
01:46Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.
00:58Symbiosis
Symbiotic relationships are long-term, close interactions between individuals of different species that affect the distribution and abundance of those species. When a relationship is beneficial to both species, this is called mutualism. When the relationship is beneficial to one species but neither beneficial nor harmful to the other species, this is called commensalism. When one organism is harmed to benefit another, the relationship is known as parasitism. These types of relationships often...