The dynamics of predator-prey pursuit appears complex, making the development of a framework explaining predator and prey strategies problematic. We develop a model for terrestrial, cursorial predators to examine how animal mass modulates predator and prey trajectories and affects best strategies for both parties. We incorporated the maximum speed-mass relationship with an explanation of why la...

A recent shift in managing insect resistance to genetically engineered (GE) maize consists of mixing non-GE seed with GE seed known as "refuge in a bag", which increases the likelihood of predators encountering both prey fed Bt and prey fed non-Bt maize. We therefore conducted laboratory choice-test feeding studies to determine if a predator, Harmonia axyridis, shows any preference between prey...

Various characteristics of population and community dynamics of freshwater zooplankton have been studied in the past, in attempts to increase our knowledge of how freshwater ecosystems function. A major leap forward in disentangling ecosystem processes was the discovery of communication based on chemical cues (infochemicals) in the early 1980s. Infochemicals were found to affect many aspects of...

The aim of this paper is to consider a non-autonomous predator-prey-like system, with a Gompertz growth law for the prey. By introducing random variations in both prey birth and predator death rates, a stochastic model for the predator-prey-like system in a random environment is proposed and investigated. The corresponding Fokker-Planck equation is solved to obtain the joint probability density...

A predator-prey model with logistic growth in the prey is modified to include an SIS parasitic infection in the prey with infected prey being more vulnerable to predation. Thresholds are identified which determine when the predator population survives and when the disease remains endemic. For some parameter values the greater vulnerability of the infected prey allows the predator population to ...

Synopsis Successful feeding and escape behaviors in fishes emerge from precise integration of locomotion and feeding movements. Fishes inhabit a wide range of habitats, including still ponds, turbulent rivers, and wave-pounded shorelines, and these habitats vary in several physical variables that can strongly impact both predator and prey. Temperature, the conditions of ambient flow, and light ...

We investigated daily and annual variation in the marine habitat selection of marbled murrelets Brachyramphus marmoratus (Alcidae) in the nearshore California Current System at scales of 10 to 100 km of coastline. We addressed 2 general questions: (1) how do murrelets select habitat while facing dramatic and often rapid variation in oceanographic conditions and prey availability; and (2) does s...

We tested for seasonal differences in cougar (Puma concolor) foraging behaviors in the Southern Yellowstone Ecosystem, a multi-prey system in which ungulate prey migrate, and cougars do not. We recorded 411 winter prey and 239 summer prey killed by 28 female and 10 male cougars, and an additional 37 prey items by unmarked cougars. Deer composed 42.4% of summer cougar diets but only 7.2% of wint...

Videotapes of migrant Semipalmated Sandpipers foraging in the upper Bay of Fundy were analyzed to test for foraging behaviors sensitive to prey density. Over a range of prey densities, both the number of steps set-’ and probes set-’ increased with increasing prey density. However, the number of steps between probes was constant over the range of prey densities observed. The average angle of dir...