For most of us, being devoured by something many times bigger than us would mean a gruesome, agonizing death. But for tiny snails, it's just a minor irritation...and a quick and disgustingly clever way to migrate elsewhere.
This strange behavior occurs on the island of Hahajima, Japan, where birds known as Japanese white-eyes like to eat lots of tiny land snails. Researchers have discovered that 15% of the devoured snails end up living through the experience, and they suspect the surviving snails take advantage of the experience to take up residence on different parts of the island that they could never hope to reach without a ride inside a bird's gut. The surprising genetic diversity of snails on the island backs up this hypothesis.
Researcher Shinichiro Wada explains:
"We were surprised that a high rate, about 15 percent, of snails were still alive after passing through the gut of [the] birds. 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. This is the first study showing that birds can indeed transport a substantial [number of] micro land snails in their gut alive. One of the snails fed to the bird gave birth to juveniles just after passing through the gut."
The only real trick to the snails' survival, according to the researchers, is their very small size. At just a tenth of an inch long, the snails can easily be swallowed whole by the birds. The researchers aren't sure whether the snails have any other adaptations that allow them to survive being eaten, but whatever they're doing to move around the island, it's working - albeit in just about the grossest way imaginable.
Via BBC News.