Gulls have learned to follow diving ducks and take the bottom-dwelling mussels that the ducks bring to the surface, a food source that would otherwise be inaccessible to them. Gulls are one of the ...

Consider the scaup (diving duck). On an early February day at low tide, upper Narragansett Bay, the duck is diving for clams, oysters and mussels. Each time spending 15 seconds or more under water, ...