The side effects of parachuting cats

I ran across a nice factual account of the fantastic “cat drop” story of ecological side effects immortalized in Alan Atkisson’s song.

It reminded me of another great account of the complex side effects of ecosystem disturbance, from the NYT last year, supplemented with a bit of wikipedia:

• In 1878, rabbits were introduced to Macquarie Island
• Also in the 19th century, mice were inadvertently introduced
• Cats were subsequently introduced, to reduce mouse depredation of supplies stored on the island
• The rabbits multiplied, as they do
• In 1968, myxoma virus was released to control rabbits, successfully decimating them
• The now-hungry cats turned to the seabird population for food
• A successful campaign eradicated the cats in 1985
• The rabbits, now predator-free, rebounded explosively
• Rabbit browsing drastically changed vegetation; vegetation changes caused soil instability, wiping out seabird nesting sites
• Other rodents also rebounded, turning to seabird chicks for food

An expensive pan-rodent eradication plan is now underway.

But this time, administrators are prepared to make course corrections if things do not turn out according to plan.“This study clearly demonstrates that when you’re doing a removal effort, you don’t know exactly what the outcome will be,” said Barry Rice, an invasive species specialist at the Nature Conservancy. “You can’t just go in and make a single surgical strike. Every kind of management you do is going to cause some damage.”