|African Elephants. Kenya, 2008.|
The Australian Rabbit-proof Fence is interesting because it discusses the issues around managing invasive species. I don't recall if they use that specific term in the podcast, but Australian rabbits are a classic example in invasion ecology. An interesting note, which they bring up in the podcast but do not expand upon, is the potential to introduce a virus to control rabbit populations. This is another classic example in the scientific literature concerning biological control. Biological control can be defined many ways, but the definition I currently like best can be found in Eilenberg et al. (2001): "The use of living organisms to suppress the population of a specific pest organism, making it less abundant or less damaging than it would otherwise be." And though this definition technically excludes viruses, I very much doubt the authors would dispute the fact that the use of viruses to control pest populations is, in fact, biological control. The virus referenced in the podcast is one of a group of myxoma viruses, which have been used to control rabbit populations in Europe. One one level, the argument for biological control is that it helps us avoid potentially more harmful control measures (like poisons or pesticides) and it may be naturally sustaining (such as a virus which has natural cycles within the population) making it more cost effective. More cost effective, say, than continually up-keeping a fence to exclude rabbits. However, biological control isn't always perfect and introducing a biological control agent to control another introduced species can have a run-away effect. These sorts of decisions are heavily researched and the literature surrounding the study of biological control is very interesting.