Silly rabbits! Part 1

I suppose this is a different topic than what we've typically discussed on this blog, but ecology (particularly biodiversity and invasive species) has always been a particular interest of mine and I couldn't resist passing it along after having my mind sparked by an interesting article.

Earlier this week, the results of an ecological study conducted on Australia's Macquarie Island by the Australian Antarctic Division were published in the Journal of Applied Ecology. The study, conducted on the island between 2000 and 2007, examined the progress and results of an effort first undertaken in 1985 by Tasmania's Parks and Wildlife Service to eradicate the island's population of feral cats, which were decimating the native seabird colonies on the island. Macquarie Island was discovered in 1810 by a British explorer, Frederick Hasselborough, while he was searching the Tasman Sea for new areas to hunt seals; he claimed the island for Britain and subsequently became an official part of the Australian state of Tasmania in 1901 when the Commonwealth of Australia was formed. Since that time it has more or less served as a "home base" for various Australian scientific agencies and was declared a wildlife sanctuary in 1933. After the island's discovery in 1810, it was colonized, though sparsely, by European seal and penguin hunters who accidentally brought mice and rats to the island hidden on their ships. Without natural predators on the island, the rodent population exploded and became a nuisance to the settlers by getting into their food stores; in response, the settlers released cats on the island to control the rodent population. Around the same time, the settlers also released rabbits into the wild on the island in order to have them breed and then be hunted for food. By the 1970s, the rabbit population had grown to over 130,000 and was destroying the island's native vegetation. The cats, which are now feral, have devastated the native seabird
population by killing an estimated 60,000 birds each year.

As any environmental activist could surely guess, this annihilation of the native bird population on Macquarie Island could not be allowed to continue and the Australian government (through the agency of the Tasmania Parks and Wildlife Service) stepped in with several invasive species control measures--the myxomatosis virus was introduced to kill the rabbits, which seemed at first to succeed in reducing the population to 10,000, and a massive effort was started in 1985 to rid the island of all the cats. Apparently, they had actually managed to remove all of the cats from the island by June of 2000 but, alas, the happy ending they were hoping for did not come. Instead, with the predator (cat) population gone, the rats began to multiply once again and continued the destruction of the bird colonies because rats eat young birds. Also, without the cats there to prey upon them as well, the rabbit population ballooned back up to 100,000 and are destroying the vegetation on the island causing soil erosion and landslides which have led to significant destruction of cliff nesting sites.

The Parks and Wildlife Service now estimates that it will take 24 million Australian dollars ($16.2 USD) to "fix" the erosion damage that has been caused by the unchecked rabbit population. But what does this mean "fix?" From as best I can tell, "fix" means to somehow restore the island to its' pre-discovery state and thus saving the seabirds from extinction. The problem is that this can never realistically happen; once these non-native animals (and likely non-native plants as well) were introduced onto the island, the ecosystem was permanently altered and it simply can't be restored to its original state. That's just not how nature works.

So, why does this matter? Because this is just one example of the thousands of similar initiatives that have spent billions of dollars to undertake such ecological control programs and have ended up not only unsuccessful in their original goals, but often have created problems that didn't exist previously. I sincerely feel that these failures result from a fundamental ignorance of the concept and effects of "Biodiversity," which was popularized by the brilliant biologist E.O. Wilson in 1986. Without a much greater understanding of Biodiversity and how this relates to the delicate and intricate nature of ecosystems, such projects will continue to be doomed. This is becoming increasingly important as the environmentalist lobby and environmentalist groups become more and more influential and will surely push for more such "ecosystem recovery" projects in the years to come. I would consider myself an Environmentalist and don't wish to see the government throw away billions of dollars on projects that are so ill-conceived and narrow-minded that they are doomed to fail. If we really want to help heal the damage we've done to our environment and the millions of plant and animal species that live here with us, we need to gain a much better understanding of ecosystems and the basic workings of "nature" itself. It's this that I want to focus on now, but I didn't want to write a novel here so I've decided to split this into two parts. Part 2 is still to come...