Environmental Engineering Reference
In-Depth Information
Successful management of terrestrial invasive vertebrates requires three elements:
Effective policies to ensure funds are allocated to the species and places of
1)
highest priority, and that the appropriate people fund the control—either
those who cause the problem, if they can be identifi ed, but more often
those who benefi t should pay. Appropriate long-term policies and funding
mechanisms are particularly critical if sustained control is the management
strategy being applied to the invasive species (Gibb and Williams 1994).
Effective instruments to deliver the control. These include both the avail-
2)
ability of techniques and tools to manage the animals and the capacity of
human resources to organize and do the work, especially where skills are
required. There is a problem if we have a mouse plague but neither mouse
traps nor someone who knows how to set them!
Knowledge of where and when to intervene with these tools to best effect
3)
(Choquenot and Parkes 2001). There is no point in having the perfect mouse
trap but set it where there are no mice, or when mice are not a problem, or
not setting enough when they are a problem!
h ese requirements are also governed by whether the strategic aim of manage-
ment is to stop the pest arriving, to eradicate it, to stop it spreading, or to maintain
some degree of control over it. In addition, under the sustained control strategy,
they are governed by whether the impacts of the pest on the value to be protected is
intermittent or chronic—and thus when and where to intervene (Parkes 1993).
Control tools have to meet these strategic needs, but must also do so in socially
acceptable ways, without net adverse side eff ects, and at an aff ordable or justifi able
cost. For example, a common weakness in pest control programmes is to design
the programme entirely around what is possible with the tools available, rather
than around the more important considerations of strategy (e.g. eradication versus
sustained control), appropriate scales, and the relationships between the impacts
of the pest at diff erent densities and the rates of recovery or natural fl uctuations of
population densities.
