Theoretical studies have shown a paradoxical destabilizing response of predator–prey ecosystems to enrichment, but there is the gap between the intuitive view of nature and this theoretical prediction. We studied a minimal predator–prey system (a two predator–two prey system) in which the paradox of enrichment pattern can vanish; the destabilization with enrichment is reversed, leading to stabi...

This is the first study to compare defenses to predation in closely related species of Mytilus and draws attention to the role of predation in determining their distribution, abundance and co-existence. We experimentally determined whether 2 blue mussel species, Mytilus edulis and M. trossulus, that co-exist within a hybrid zone in Newfoundland, Canada, differ in their predator-induced response...

Ecological theory suggests that prey size should increase with predator size, but this trend may be masked by other factors affecting prey selection, such as environmental constraints or specific prey preferences of predator species. Owls are an ideal case study for exploring how predator body size affects prey selection in the presence of other factors due to the ease of analyzing their diets ...

Theoretical studies have shown a paradoxical destabilizing response of predator-prey ecosystems to enrichment, but there is the gap between the intuitive view of nature and this theoretical prediction. We studied a minimal predator-prey system (a two predator-two prey system) in which the paradox of enrichment pattern can vanish; the destabilization with enrichment is reversed, leading to stabi...

study of the spatial distribution of a pest and its natural enemies provides better decision tool for integrated pest management. the spatial distribution and seasonal activity of panonychus ulmi (koch) and its predator zetzellia mali (ewing) were studied in an apple orchard in khoramdareh (zanjan province, iran) during 2007. the interaction (density dependence) between the prey and its predato...

Determining the impact of habitat manipulation and predator species diversity on prey suppression is crucial in developing predictions for the impact of biological control programs. Biological control literature contains controversial evidence for the impact of increased predator species diversity and habitat manipulation on prey suppression. We investigated the individual and combined effects ...

One of the ecological theories has proposed that high species diversity can be maintained by predation, and several experimental studies showed that a few predator individuals with positive frequency-dependent behavior were able to maintain the coexistence of two prey types. However, in a natural environment, when a single predator species regulates the diversity of prey species, it is likely t...

It is well established that species richness of primary producers and primary consumers can enhance efficiency of resource uptake and biomass production of respective trophic levels. At the level of secondary consumers (predators), however, conclusions about the functional role of biodiversity have been mixed. We take advantage of a recent surge of published experiments (totaling 46 since 2005)...

We extend two-species models of individual aggregation or clustering to two-dimensional spatial domains, allowing for more realistic movement of the populations compared with one spatial dimension. We assume that the domain is bounded and that there is no flux into or out of the domain. The motion of the species is along fitness gradients which allow the species to seek out a resource. In the c...

The gut contents of three species of insect predators that were fed either a variable or a fixed number of pink bollworm eggs but held at variable time and temperature regimes were assayed by an indirect enzyme-linked immunosorbent assay (ELISA). The sensitivity and efficacy of the monoclonal antibody-based ELISA was dependent on the predator species examined. Small predatorsweremore immunoresp...