Stomach stones to grind up bones? Illustrated is a medium-sized shag which has been given the common name spotted shag. Of interest is the finding of numerous small stones in the gizzards of spotted shags. Science is divided on the purpose of the stones but one scientist studied the stomach contents of over 100 shags that had been feeding and found that shags without the stones usually had undigested fish and bones in their stomachs while those with stones had stomach contents that were well ground up and digested. Little piles of regurgitated stones can often be found where the spotted shags roost.

Source: Stuff July 05, 2017 01:18 UTC