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as a function of abundance is dictated by the Ricker logistic equation (f(N)) and pro- portionate harvest (H(N)) by the fixed ef ...
alternative ways of earning income. So the costs and benefits of resource use are measured relative to other forms of economic i ...
economic equilibrium is reached at which supply matches demand. This kind of open market is highly idealized: in practice there ...
If demand is modest relative to renewable resource supplies, then the classic supply–demand relationship occurs. There is a sing ...
Rather than culling males at random, however, the optimal economic decision would be to collect ivory from individuals that have ...
realistic in most economic models) halves the value of all future harvests. Severe dis- counting can therefore change the attrac ...
policy should always be evaluated in the light of stochastic variation in population growth. In a stochastic world, harvesting a ...
20 Wildlife control We show that a control operation is similar to a sustained-yield exercise but is conceptually more complex. ...
If the density of a population is lowered by control measures, the standing crop of renewable resources (e.g. grass needed by a ...
country. Table 20.2 lists the sequence of official justifications for government-funded control of deer from 1920 onwards (Caugh ...
introduced disease, shooting, and trapping reduced the cats. The petrel breeding suc- cess increased from 0 –23% (1979 – 84) to ...
3 Density is stabilized by the removal each year of a constant proportion of the population, provided that proportion is lower t ...
Africa (Bloomer and Bester 1992), and Lord Howe Island (Hutton 1998). Foxes have been removed from 39 islands of Alaska (Ebbert ...
The usual method of use against insects – flooding the population with sterile males is dependent on the females mating only on ...
because its effect is specific to particular species and habitats. It must be examined by way of carefully designed field experi ...
be reinoculated on an annual basis. This means that the technique is limited to animals that are easy to capture and from small ...
particularly critical of the claims made for commercially produced ultrasonic devices and of the standard of experimental testin ...
Ecosystem management and conservation 21 Most of the previous chapters have focused management and conservation on indi- vidual ...
characteristic groups that define that community. Communities exist within the abiotic physical and chemical environment, and th ...
the next-but-one level, and non-linear effects where competitors within the predator or prey levels respond to changes in one of ...
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