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maintain an effective metapopulation structure (Murphy and Noon 1992; Noon and McKelvey 1996). This kind of management controver ...
Population regulation, fluctuation, and competition within species 8 In this chapter we first describe the theory and evidence f ...
Canada shows the clearest (Fig. 8.3), as indicated by the furs collected by trappers for the Hudson Bay Company over the past tw ...
Populations have inputs of births and immigrants and outputs of deaths and emigrants. For simplicity we will confine discussion ...
Since b(or B/Nt) is constant in this case we describe it as density independent(i.e. it is unrelated to density). In real popula ...
Populations are often disturbed from their equilibrium, K, by temporary changes in limiting factors (a severe winter or drought ...
indicated by the range of K. Figure 8.6a shows that this range of Kis relatively small when the density-dependent mortality is s ...
through culling or weather events it may return to the same population size. To distinguish the equilibria produced by predation ...
Survivorship can be calculated over varying time periods by the method of Pollock et al. (1989). Mortality caused by predators c ...
Yellowstone National Park (Houston 1982). Before 1930, the population estimates ranged between 15,000 and 25,000. Between 1933 a ...
Just by chance there may be for a time a correlation between density and environ- mental factors. However, if we take many separ ...
POPULATION REGULATION, FLUCTUATION, AND COMPETITION WITHIN SPECIES 119 0.2 0 0.2 0.6 Winter mortality 0.2 2.0 3.0 3.4 3.8 Log ...
100 studies of terrestrial and marine mammal populations where density dependence was detected. Delayed density dependence has b ...
conditions of superabundant food following good rains, the reproductive rate of females increased faster than the predation rate ...
the fact that Nis enormous, the population will similarly display modest change from year to year. This is because the per capit ...
of change (Fig. 8.7) reminiscent of the logistic model. Indeed, perturbation is an import- ant ingredient in detecting natural r ...
to survive, but rather anticipate that by chance sometimes a larger fraction will survive, sometimes a smaller fraction. We cons ...
where μ=0 and σ=0.19. We then combine the random normal deviate at any point in time (εt) with the rate of increase predicted by ...
(Fig. 8.13), so the population declines rapidly. Repetition of this boom–bust pattern of overshooting the carrying capacity and ...
Now, let us consider the pattern arising when rmax=3.3 (Fig. 8.19). The recruit- ment curve has a pronounced hump and intersects ...
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