Crocodiles, spiders and leeches

11 04 2011

I just wrote a fun little piece for a new section in the journal Frontiers in Ecology and the Environment that they’re calling Trails and Tribulations. The basic idea is that the author recounts a particularly interesting field-related experience through which an ecological concept is woven.

Editor-in-Chief Sue Silver said that I could reproduce my article here as long as I acknowledged Frontiers and the Ecological Society of America. It was fun to write, and I hope you enjoy it too [the PDF of the article is available free of charge here].

“So does each team get a hand gun?”

“No, you get an oar”

“What good is an oar?”

“Listen, mate. When a 3-metre croc jumps out of the swamp at you, there is nothing more natural in the world than to thump him with a big stick. It’s an autonomous response. With a gun, IF you manage to keep it dry, and IF you manage to get it out in time before the croc bites off your head, chances are you’ll just shoot the bloke in front of you anyway. So you get an oar.”

“Fair enough”.

That is an approximate, paraphrased reproduction of the initial conversation I had with renowned Australian crocodile biologist, Grahame Webb, just prior to my first (and as it turns out, only) trip to collect crocodile eggs for his Darwin wildlife park and crocodile farm. I volunteered to take part in the collection because I had recently begun working with Grahame and his team tracking the world’s largest crocodile species – the saltwater or estuarine crocodile Crocodylus porosus – and modelling aspects of its populations (Bradshaw et al. 2006). Having already been out on several occasions to harpoon and satellite-tag animals (some measuring > 4 m) on the Mary River, and cage-trap others in Kakadu National Park, I thought a little egg collection would be a proverbial walk in the park. Little did I know that it would end up being one of my more memorable experiences.

Let me walk you through the process. First, you wait until the height of the wet season and drive out as far as you can toward the breeding swamp of interest (in this case, Melacca Swamp in the Adelaide River flood plain, about one hour’s drive from Darwin). Then you and two other loonies pile into a small helicopter equipped with landing pontoons which ferries you to one of many previously identified crocodile nests. Because there is usually too much vegetation around the nest itself, the helicopter must land about 100-300 m away. Clothed only in long pants, a long-sleeved shirt and cotton gloves to protect your skin from the slicing blade grass, you jump off the helicopter’s pontoons into impenetrably murky, chest-deep water. One of the team drags an esky (chiller box into which eggs will be placed) and another carries an oar. As the noise of the departing helicopter becomes a faint buzz, you suddenly realise via the rapid expansion of your terminal sphincter that you are in the middle of a crocodile-filled swamp – and you are holding an oar. Read the rest of this entry »