The conflict between increasing human population and biodiversity conservation is one of the
IUCN's key threatening processes. Conservation planning has received a great deal of coverage
and research as a way of conserving biodiversity yet while theoretically successful it has
never been tested. Simple lines on maps to illustrate conservation areas are unlikely to be
successful in the light of human encroachment. It may be that some form of overt display is
necessary to ensure the protection of reserves. This may be signage presence of guards rangers
or physical fencing structures. The need for some form of barrier goes beyond restricting human
access. The megafauna of Africa pose a genuine threat to human survival. In southern Africa
fences keep animals in and protect the abutting human population. Elsewhere fencing is not
considered important or viable. Where poverty is rife it won't take much to tip the balance
from beneficial conservation areas to troublesome repositories of crop-raiders diseases and
killers. Conversely in New Zealand fences are used to keep animals out. Introduced species
have decimated New Zealand's endemic birds reptiles and invertebrates and several sites have
been entirely encapsulated in mouse-proof fencing to ensure their protection. Australia faces
the same problems as New Zealand however surrounds its national parks with cattle fences.
Foxes and cats are free to enter and leave at will resulting in rapid recolonisation following
poisoning campaigns. How long will these poison campaigns work before tolerance aversion or
resistance evolves in the introduced predator populations?
