We consider a two-competitor/one-prey model in which both competitors exhibit a general functional response and one of the competitors exhibits a density-dependent mortality rate. It is shown that the two competitors can coexist upon the single prey. As an example, we consider a two-competitor/one-prey model with a Holling II functional response. Our results demonstrate that density-dependent m...

the functional response of a predator is the base of prey-predator dynamics. functional response of serangium montazerii fã¼rsch at different egg densities (50, 100, 150, 200 and 250) of dialeurodes citri (ashmead) was studied in an open-patch experiment, in a growth chamber (25 â± 1â°c, 65 â± 5% rh and a photoperiod of 16: 8 l: d h) on ‘thompson’ navel orange (citrus sinensis cv. thompson)...

Top predators that forage in a purely exploitative manner on smaller stages of a size-structured prey population have been shown to exhibit an Allee effect. This Allee effect emerges from the changes that predators induce in the prey-population size distribution and represents a feedback of predator density on its own performance, in which the feedback operates through and is modified by the li...

Recent work indicates that the interaction between body-size-dependent demographic processes can generate macroecological patterns such as the scaling of population density with body size. In this study, we evaluate this possibility for grazing protists and also test whether demographic parameters in these models are correlated after controlling for body size. We compiled data on the body-size ...

Geographic variation in behaviour of individuals within a species is well known (Foster & Endler 1999), both across ranges (Iriarte et al. 1990) and locally (Hertz & Huey 1981). For predators, variation in prey use within a given site is often seasonal (Brillhart & Kaufman 1995), and related to changes in relative abundance and/or vulnerability of various prey (Kunkel et al. 2004). Behavioural ...

Understanding the diving behaviour of diving predators in relation to concomitant prey distribution could have major practical applications in conservation biology by allowing the assessment of how changes in fine scale prey distribution impact foraging efficiency and ultimately population dynamics. The southern elephant seal (Mirounga leonina, hereafter SES), the largest phocid, is a major pre...

We study the qualitative properties of population cycles in a predator-prey system where genetic variability allows contemporary rapid evolution of the prey. Previous numerical studies have found that prey evolution in response to changing predation risk can have major quantitative and qualitative effects on predator-prey cycles, including: (1) large increases in cycle period, (2) changes in ph...

The introduced dispersal-foraging game is a combination of prey habitat selection between two patch types and optimal-foraging approaches. Prey's patch preference and forager behavior determine the prey's survival rate. The forager's energy gain depends on local prey density in both types of exhaustible patches and on leaving time. We introduce two game-solution concepts. The static solution co...