Dr Paul McInerney and Dr Michael Shackleton, both alumni of La Trobe and researchers at the University's Murray-Darling Freshwater Research Centre, traveled to Cambodia's Cardamom Mountains to study the natural habitat of the Siamese crocodile.
The project was part of a collaboration between La Trobe University, Fauna and Flora International and the Royal University of Phnom Penh, aimed at better understanding aquatic ecosystems at crocodile release sites.
With less than 400 Siamese crocodiles left in the wild, Dr McInerney said finding the best river sites to re-release the crocodiles was pivotal to the long-term survival of the species.
“A lot of effort is put into catching these juvenile crocodiles, raising them, and re-releasing them to sites. But not much is known about the conditions at those release sites, particularly around how much food is available for the crocs,” Dr McInerney said.
The researchers conducted fish surveys in three tropical rivers to determine food webs and compile a DNA library of fish species.
“We’re now at the stage of sequencing DNA samples that we collected from fish in three remote rivers in south-western Cambodia," Dr McInerney said. "We also have samples of fish gut content that we will process to determine what each different fish species eats. Information generated from these analyses will help us to understand the trophic dynamics within these ecosystems and we can start making links between the number of fish and what they’re eating, and the available food resources for crocodiles,” he said.
The research team trekked into remote areas with people employed as ‘crocodile wardens’ from surrounding villages. Dr McInerney said it would have been impossible to find the crocodile sites without the wardens’ help.
“We got pretty close to the crocs, perhaps a bit too up-close at times,” Dr McInerney said.
“We were out in the jungle for weeks with no mod-cons, so on one occasion I decided to have a bath in a little rock pool that I thought was relatively safe. Later on that night, I went back to the same rock pool and happened to shine my torch light on it, only to find a crocodile sitting right where I had been. It made me think twice before having my next bath.”
Dr McInerney, who completed his Honours and PhD research at La Trobe, said he hoped the research would strengthen conservation efforts for the crocodile species.
“The fact is, crocodiles aren’t as cute and cuddly as other animals that attract more money from the public. People don’t always see them as animals that should be protected, yet they are really important in these systems because they’re the apex predator – they’re the top of the food chain and their prevalence influences everything around them.”
Dr McInerney is an aquatic researcher at the Murray Darling Freshwater Research Centre, a partnership between CSIRO and La Trobe. The centre is one of the largest and longest-running freshwater research centres in Australia.