Foraging theory seeks to explain how the distribution and abundance of prey influence the evolution of predatory behaviour, including the allocation of effort to searching for prey and handling them after they are found. While experiments have shown that many predators alter their behaviour phenotypically within individual lifetimes, few have examined the actual evolution of predatory behaviour...

Population density in plants and animals is thought to scale with size as a result of mass-related energy requirements. Variation in resources, however, naturally limits population density and may alter expected scaling patterns. We develop and test a general model for variation within and between species in population density across the order Carnivora. We find that 10,000 kilograms of prey su...

Predators affect prey and their resources by changing the density and traits (e.g. morphology and behavior) of those prey. Ecological studies and models of community dynamics, however, typically only incorporate how changes in prey densities, rather than their traits, affect community dynamics. In a recent meta-analysis, Preisser et al. show that trait effects are as large, if not larger than d...

t f m Immunological methods have been widely used to identify key predator species and qualitatively evaluate predation of target prey. However, despite the quantitative nature of many immunoassays, the translation to number of prey attacked has been problematic because of the many factors that confound interpretation of the strength of the immunoassay response. We developed a new predation mod...

Throughout the study of ecology, there has been a growing realization that indirect effects among species cause complexity in food webs. Understanding and predicting the behavior of ecosystems consequently depends on our ability to identify indirect effects and their mechanisms. The present study experimentally investigates indirect interactions arising between two prey species that share a com...

A number of studies show that predators can depress prey growth rates by inducing reductions in foraging activity, but the size of this non-lethal effect is quite variable. Here I investigate how prey density and resource productivity may alter the extent to which predators depress the growth rates of their prey. Theory predicts that when resources are overgrazed, an increase in predation risk ...

In this paper, the effects of refuges used by prey on a predator-prey interaction with a class of functional responses are studied by using the analytical approach. The refuges are considered as two types: a constant proportion of prey and a fixed number of prey using refuges. We will evaluate the effects with regard to the local stability of the interior equilibrium point, the values of the eq...

It is important to predict how many individuals of a predator species can survive in a given area on the basis of prey sufficiency and to compare predictive estimates with actual numbers to understand whether or not key threats are related to prey availability. Rugged terrain and low detection probabilities do not allow for the use of traditional prey count techniques in mountain areas. We used...

Predatory efficiency of Diplonychus rusticus (Fabricius) was recorded at different prey density with different salinity ranges. When the salinity level (ppt) was increased, the predation rate of the bug decreased. Fifth nymphal stage showed higher predation in the 2, 4 and 6 ppt levels of salinityin both 1 hr and 24 hr period of exposure at prey densities 50, 100, 150 and 200. At prey density 1...

Predator density, refuge availability, and body size of prey can all affect the mortality rate of prey. We assume that more predators will lead to an increase in prey mortality rate, but behavioral interactions between predators and prey, and availability of refuge, may lead to nonlinear effects of increased number of predators on prey mortality rates. We tested for nonlinear effects in prey mo...