It isn’t black and white, doesn’t eat bamboo, and certainly isn’t cuddly – no one seems to know why this largest of Australian land snails is called ‘panda’. Think of an ordinary garden snail but blown up to a size where the shell is 10 cm across and you’ll get the general idea. The giant panda snail lives in Big Scrub Rainforest remnants and you may be lucky enough to see one if you look in the right place.
Giant panda snails (Hedleyella falconeri) live in east-coast rainforests from south-east Queensland south to Barrington Tops in NSW. The Big Scrub falls within their range and you can find them, for instance, in the Nightcap National Park.
During the day, you’re likely to find their empty shells on the ground as the living ones are hiding out in the leaf litter, under fallen logs, and at the base of strangler figs.
They are avoiding both drying out and their predators – the noisy pitta, lyrebird and brush turkey scratch through the leaf litter in search of snacks and such a large snail would provide a tasty treat for those birds. A pitta will smash a snail on a rock to get at the soft body. At night the snails can be found at the base of fig trees or moving through the leaf litter, especially after wet weather meandering randomly across the forest floor, feeding on some of the mushrooms that develop after rain.
Not much is known about their ecology because very few studies have been done, but a 2002 study by Michael Murphy of NSW National Parks, published in Molluscan Research 2002, 22, 149–164, tracked the movement of six of these snails over a couple of weeks. The study snails moved in a wiggly fashion an average of 8.7 metres a night, with the maximum being 21 metres, so they can cover quite an area. Snail eggs were discovered with one of these snails in a depression covered with leaves; each egg was creamy-white with a rubbery texture, weighing about 2 grams and about 1.5 centimetres in diameter – a big egg for a big snail.
So if you go out in the woods on a rainy night, you’re in for a big surprise – you just might find a giant … panda snail!
Update: for size comparison, here is the African giant tiger land snail (Achatina achatina).