The distribution and abundance of swift foxes (Vulpes velox) has declined from historic levels. Causes for the decline include habitat loss and fragmentation, incidental poisoning, changing land use practices, trapping, and predation by other carnivores. Coyotes (Canis latrans) overlap the geographical distribution of swift foxes, compete for similar resources, and are a significant source of m...

The flounder, Platichthys flesus, is the most abundant flatfish species in the northern Baltic Sea. Juvenile P. flesus are important epibenthic predators on shallow sandy bottoms in this area, and play an important role in structuring benthic infaunal communities by both lethal and sublethal predation. These areas are affected by periodic oxygen deficiency during summer and autumn when drifting...

For some salmon populations, the individual and population effects of sea lice (Lepeophtheirus salmonis) transmission from sea cage salmon farms is probably mediated by predation, which is a primary natural source of mortality of juvenile salmon. We examined how sea lice infestation affects predation risk and mortality of juvenile pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon, and dev...

Methods for predicting the probability and timing of a species' extinction are typically based on single species population dynamics. Assessments of extinction risk often lack effects of interspecific interactions. We study a birth and death process in which the death rate includes an effect of predation. Predation is included via a general nonlinear expression for the functional response of pr...

In contrast to the neutral population cycles of the deterministic mean-field Lotka–Volterra rate equations, including spatial structure and stochastic noise in models for predator-prey interactions yields complex spatio-temporal structures associated with long-lived erratic population oscillations. Environmental variability in the form of quenched spatial randomness in the predation rates resul...

Predation can play an important role in the evolution and maintenance of prey colour polymorphisms. Several factors are known to affect predator choice, including the prey’s relative abundance and conspicuousness. In polymorphic prey species, predators often target the most common or most visible morphs. To test if predator choice can explain why in Midas cichlid fish the more visible (gold) mo...

Two population oscillations dominate terrestrial community dynamics in northern Canada. In the boreal forest, the snowshoe hare (Lepus americanus) fluctuates in cycles with an 8-10 year periodicity and in tundra regions lemmings typically fluctuate in cycles with a 3-4 year periodicity. I review 60 years of research that has uncovered many of the causes of these population cycles, outline areas...

Predator-induced changes in physiology and behaviour may negatively affect a prey's birth rate. Evidence of such indirect predator effects on prey demography remains scarce in birds and mammals despite invertebrate and aquatic studies that suggest ignoring such effects risks profoundly underestimating the total impact of predators. We report the first experimental demonstration of indirect pred...

1. Predation risk to insects is often sizeor stage-selective and usually decreases as prey grow. Any factor, such as food quality, that accelerates developmental and growth rates is likely to reduce the period over which prey are susceptible to size-dependent predation. 2. Using field experiments, several hypotheses that assess growth, development, and egg production rates of the rangeland gras...