Snails Survive Being Eaten by Birds    [29-07-2011] Recently, a graduate student and his colleagues at Tohoku University in Japan conducted an interesting experiment. They fed more than 100 snails to captive birds to see whether or not the snails could survive being eaten. Researchers studying the feces of wild Japanese white-eye birds noticed that there was a surprisingly large amount of snails still alive and intact in the fecal matter of the birds. Tohoku University’s graduate student, Shinichiro Wada, tested this finding by feeding captive white-eyes, as well as brown-eared bulbul birds hundreds of tiny snails called Tornatellides boeningi. This particular species of snails is only 0.25-centimeter-long and is commonly found on Hahajima Island, about 1,000 kilometers south of Tokyo. Wada and his team found that about 15 percent of the snails passed through both species of birds alive. One snail that they found even gave birth shortly after being passed through the feces! The length of digestion takes about 30 minutes to two hours. It is still a mystery as to how they manage to survive being eaten. Their small size could help prevent their shells from cracking and like many land snails, they also have the ability to close their shell openings with a mucus film called an epiphragm. “This may be a big factor, because their tiny shell aperture and epiphragm would prevent inflow of [the bird’s] digestive fluids,” Wada said. The snails may also hitch a ride through the feces of birds. The team found that, in the wild, this species of tiny snails was most likely to be discovered in different locations and genetic groups. While a few of the T. boeningi snails may migrate and get around through the digestive tract of white-eye birds, it is probably still very difficult for them to go very far.     출처: 어린이 영자신문 키즈타임즈 (www.kidstimes.net)