Stuart on Nature - Blog Post

We have often discussed the problem of small conservation areas (“pocket handkerchief”) and that in the long-term they and their biota are doomed to decline.  Often surrounded by man-made development, whether urban, agricultural or recreational, there is little, or no, chance that new genetic material will be introduced through natural means. This is especially the case for mammals, other than perhaps bats!

The concept of greenbelts, or wildlife corridors, holds out some hope even for high profile species such as tigers, elephants and the humble honey possum.  Broadly defined the wildlife corridor is an area of habitat, usually linear, that connects wildlife populations that have been separated by the activities of man.  In this way previously isolated mammal (and other groups) populations are able to move through these corridors to reach similarly cut off populations.  This can serve to prevent the negative impacts of inbreeding and help to increase genetic diversity. Establishment of corridors can also help repopulate suitable habitat with a species that has been eradicated for whatever reason.

Some corridors can be extremely successful even when seemingly very narrow but they can be easily impacted on by even minor human activities.

Our first encounter with the corridor concept was in south-western Australia where narrow belts of natural vegetation allowed the movement of small species, such as the Honey Possum (Tarsipes rostratus), to avoid the open cleared areas of agricultural land that dominated the region.

The most ambitious wildlife corridor system is that for the Jaguar (Panthera onca) which conservationists hope will eventually provide a “highway” system known as the “Meso-American Biological Corridor” that can be used by jaguars (and of course many other species) to link them with existing conservation areas and density hot-spots. Small sections of this corridor system are in place but the distance between northern Mexico and northern Argentina is great and the obstacles to achieving this objective are daunting.  These problems include politicians, business and farming interests, land poverty and in a few cases what we shall call negative tourism.

Another cat for which efforts are being made to establish corridors is the Tiger (Panthera tigris), especially in India.  Although some corridors linking conservation areas are in place, India has tremendous human overpopulation problems and it may prove much more difficult to establish and maintain corridors here than in much of South America.  India has established some 80 wildlife corridors to allow the movement of wild Asian Elephants (Elephas maximus) between suitable areas of habitat. This does reduce conflict with man to a certain extent but there are still regular raids into agricultural areas.  Other species of course do benefit from these corridors.

There are many situations and species in Africa that would benefit from this wildlife corridor concept but long term management would present serious difficulties.  Probably the greatest “road blocks” to implementing wildlife corridors are extreme poverty and hunger for land and its biota, corrupt politicians and wildlife authorities and, it has to be said, the lack of a conservation ethic or frame of mind in many quarters.  Given the drastic decline in populations of such dominant species as Lion (Panthera leo) and Savanna Elephant (Loxodonta africana) and the increasing isolation of populations a wildlife corridor network may be the only way to ensure that these and many other species survive into the next century.