Freshwater Crocodiles (Crocodyllus Johnstoni)
These amazing creatures have thrived in the waters of Lake Argyle.
Originally around 350 freshwater crocodiles lived in a few waterholes in the Ord River and now their population is roughly estimated to be approximately 35,000 (Dept. of Environment and Conservation survey 2010)!
As the lake filled in the early 1970’s the higher points of land became over 70 islands. Many animals were rescued (operation Ord Noah) as the tops of some hills became submerged and the remaining animals living on the islands have adapted to their new environment.
Because most of the islands are quite small, many of the usual predators of crocodile eggs are not able to survive. The wave activity washing around the islands wash up embankments of sand or loose stones and gravel which provide the ideal nesting sites for the crocodiles to lay their eggs. Normally around 90% of Freshwater Crocodiles eggs are eaten by predators, but in this unique environment many more are able to survive due to the lack of predation. This “perfect” breeding environment and plentiful supply of fish has meant that the crocodile population has increased very quickly.
During the cooler months it is often very easy to see crocodiles when boating on the lake, but in the wet season the water is much warmer and they are more active which makes them more difficult to see.
Is it safe to swim?
Freshwater crocodiles are generally very timid and primarily eat insects and small fish. As with all native wildlife these amazing creatures should be treated with respect and not interfered with. At no time should you attempt to approach or feed Freshwater Crocodiles as this may result in accidental injury to the animal or yourself. The lake is considered safe to swim in, but as always, swimming in Northern Australian waterways is totally at your own risk.
Are there any Salties?
Freshwater Crocodiles can only live in freshwater, whereas Saltwater Crocodiles (Estaurine Crocodiles – Crocodyllus Porosus) can survive in fresh or saltwater. Salties can survive in Lake Argyle and the occasional small one has been found entangled in fishermens’ nets, the largest being approximately 1.5 metres long! It is believed these are only small individuals that have travelled long distances overland during a big wet season and have ended up in the lake. There is no evidence of Saltwater Crocodiles breeding in Lake Argyle. The Locals consider the lake safe, but obviously swimming is totally at your own risk!
Current research on Freshwater Crocodiles on Lake Argyle.
For the latest update about crocodiles in Lake Argyle - go to http://www.bio.usyd.edu.au/shine/people/profiles_students/somaweera_ruchira.shtml
