Thursday, 1 January 2009

Heron aid

We've got a rabbit plague at work. Not that this is unusual. The whole country has a problem with Flopsy, Mopsy, Cottontail and Co. Too many rabbits in Australia.

How do we deal with them? It's too late for rabbit-proof fences. And lead-based techniques aren't effective on a large scale. Biological control — first myxoma virus and then calicivirus — did put a dent in the population but the bunnies have bounced back. Rabbits are everywhere and they're breeding like … well … do I really have to finish that sentence?

So, enter a new form of biological control: the European grey heron (Ardea cinerea). If you haven't seen the photos of a Dutch heron engaging in leporicide, here's the link. Cheaper than fences, quieter than shotguns, prettier than myxomatosis … an army of ravenous grey herons could clean up the rabbits in no time.

But there's a flaw in the plan. And it's not a small one.

There are no grey herons in Australia. (Oh, they might pop in occasionally when they've lost their bearings but they're not common visitors.) Given our track record with introducing vertebrates for biological control (cane toads, common mynas), bringing in hordes of them could only end badly. So is there a native equivalent that we might be able to train?

First, the bad news. Only one species is close in height and weight — the great-billed heron (Ardea sumatrana) of the tropical coast. Now here's the good news. White-necked herons (Ardea pacifica) and great egrets (Ardea alba) are almost as big and occur over the whole continent. All we need to do is train them to kill rabbits and we've got a winner.

Herons could also take care of our surplus of starlings. (Although this one needs to put in more effort.)

And if we get the pelicans involved, there'd be no end to what we could achieve. Especially if we fitted laser beams to their heads.

Perhaps I'll put in a grant application for one million dollars.



Rabbits are everywhere and they're breeding like...humans?

Snail said...

I was going to type 'cockroaches' but your answer is better!