Tiny snails are able to survive digestion by birds

Some snails survive after being eaten by birds, Japanese researchers have found.

Researchers found that 15 per cent of the snails eaten by Japanese white-eye or mejiro birds survived digestion and were found alive in the birds' droppings.

This evidence suggests that bird predation could be a key factor in how snail populations spread, reports the BBC.

While it has long been known that birds that eat fruit can spread a plant's seeds through their droppings, the study points to some invertebrates being spread the same way.

In the lab scientists fed the birds with the snails to find out whether any survived the digestive process.

"We were surprised that a high rate, about 15 per cent, of snails were still alive after passing through the gut of [the] birds," explained researcher Shinichiro Wada.

"This is the first study showing that birds can indeed transport a substantial [number of] micro land snails in their gut alive."

The main factor allowing the snails to survive being eaten is their small size, according to the scientists.

At an average of 2.5mm the micro snails fared much better than larger species in previous studies whose shells were severely damaged when eaten by birds, they added.