"Blue whales rely on large aggregations of dense krill to sustain their extreme body size, so they continuously dive and feed throughout the day when high-density prey patches are present," said Jeremy Goldbogen, at Cascadia Research, a non-profit US research organisation in Olympia, Washington.
Alternative versions of the model, including density dependent prey encounter rates and a positive relationship between number of prey captured and predator survival, produced nearly identical results to those of the simpler model presented here.
Δx t) = x(t+) - x t), where x(t+) represents the density of prey population X immediately after the impulsive releasing (or harvesting) at time t, while x t) represents the density of prey population X before the impulsive releasing (or harvesting) at time t.
Under low predator density, the prey size frequency distribution remains relatively unaffected, and this will lead to stabilizing selection to utilize the most abundant prey size (Fig. 1D).
where x ( t ) and y ( t ) represent the population density of prey and predator at time t, respectively.
Let (x t)) denote the population density of prey, (y_{1}(t)) and (y_{2}(t)) represent the population density of the susceptible predator and the infected predator, respectively.
where Ω is a bounded domain in R N ( N ≥ 1 ) with smooth boundary ∂ Ω, u, v represent the population density of prey and predator, respectively.
Here, (x t)) and (y(t)) are the density of prey and predator populations at time t, respectively, and they are all positive numbers.
In contrast, fisheries acoustics offer a minimally invasive approach to measure sound scattering organisms and to provide an acoustic density of prey.
Potential environmental factors that might have induced plastic responses are temporal changes in growth opportunity due to changes in density of prey, density of competitors, or in temperature.
