Vince Kessner is on the hunt for snails, ‘the sleeping beauties of Fish River’ he says.
We’re Bush blitzing at Fish River Station in the Northern Territory’s Top End, looking for all sorts of creatures — fish, reptiles, small mammals, frogs, dragonflies, butterflies, spiders as well as snails.
‘Snails always come back to the same place to sleep, and if it’s a really good spot – moist and sheltered – sometimes you’ll find a hundred snails there,’ Vince says.
Snails sleep during the entire dry season. To get ready for their snooze, they form a semi-permeable membrane at the opening of their shell. The membrane, made of saliva, allows moisture in but not out, keeping the snail hydrated. When the first rains of the wet season begin they wake up and get busy eating and reproducing. The best place to find snails is on limestone, which provides calcium for their shells. They also like areas where there are three or more layers of rock providing moisture and shelter . The oldest snails are usually found in the deepest layers, while the young ones and teenagers are found near the surface.
‘At the top they are more vulnerable to predators and drying out, so there is a high mortality of young and juveniles’ says Vince.
Snails are vulnerable to predators such as small mammals, grubs and carnivorous snails. Some snails eat the shell of others to get the calcium. ‘When you see a small round hole in a dead snail’s shell, that’s usually been made another snail. They have tongues with rows of spikes. They just file away the shell, and they can do it pretty quickly’ say Vince.
Mim Jambrecina, Bush Blitz
Bush Blitz is a biodiversity discovery program between the Australian Government, BHP Billiton and Earthwatch Australia which aims to document the plants and animals across Australia’s National Reserve System.
Fish River Station is a new addition to the National Reserve System, having been bought for conservation last year by the Indigenous Land Corporation, The Nature Conservancy and the Pew Environment Group with funding assistance from the Australian Government and support from Greening Australia.