On a recent river cruise through a stretch of tropical rainforest on the northeast coast of Queensland, Australia, tour guide David White spotted a resident saltwater crocodile sinking its teeth into a file snake. Known to locals as "Lizzie", the croc was seen sliding out of the river with a sizeable serpent clasped between her jaws. Lizzie seemed to grapple for some time with her meal, before eventually swallowing it and washing it down with a drink of water.


According to White of Solar Whisper Daintree River Crocodile and Wildlife Cruises, it took around two hours for the croc to get through her meal. "File snakes, not other snakes, seem to take a long time to eat," he explained on Facebook. "I don't know why, they are not that big but take a while to swallow." Saltwater crocodiles are opportunistic feeders and will prey on everything from fish and crabs to birds, turtles, pigs, and – on very rare occasions – humans. 

Named for their ability to thrive in saline environments, saltwater crocodiles are typically found in brackish, estuarine waters close to the coast, but are comfortable in freshwater habitats as well. They owe their saline-tolerant ways to a specialised gland located on their tongues which is responsible for excreting excess salts – a talent shared by a host of other species such as sharks, rays, skates and seabirds. 

As for that post-snake drink of water, well, crocodiles – like many other carnivores – probably don't need to drink regularly in order to survive as they acquire sufficient fluids from their prey, but they'll quench their thirst when they can. Although they have a lingual gland to take care of excess sodium, saltwater crocs will not chug back seawater, preferring fresh aqua when available.