Hitchhiking snails scoffed, pooped out alive by birds

Scientists have discovered that certain species of Japanese snail can not only survive being eaten and then excreted by birds, they actually benefit from the process in many cases by finding themselves deposited in new uncropped habitats.

The revelations were uncovered by scientifically feeding Japanese white-eye or mejiro birds with the tiny land snail Tornatellides boeningi in lab tests. A surprisingly high proportion of the snails, some 15 per cent, survived the process, solving a knotty conundrum which has left the Japanese snail-boffinry community baffled until now.

"Biogeography of wingless terrestrial invertebrates, in particular snails, is often faced with mysterious long distance dispersal patterns that can only be explained by hand waving arguments involving birds' feet or guts or cyclones," Shinichiro Wada, one of the investigating experts, tells the BBC.

Now it appears that the hardy gastropods are in fact travelling inside the birds rather than on them: the elite few who survive the avian gastric process being deposited – perhaps as part of a beneficial rain of fertiliser from high altitude – in pastures new.

According to Wada, one of the snails in the study actually gave birth shortly after experiencing the perils of bird-borne transit. It's thought that just one small bird can carry a large number of the tiny 2.5mm snails at once, permitting a fair few to arrive alive at their destination.

Full details of the study are published in the Journal of Biogeography. ®