Forster's Tern

These medium-sized white birds are often confused with Common terns due to their coloration. Forster’s terns have a longer tail than the common tern and their nonbreeding plumage features a black eye patch. These birds have a pale gray back and white below with orange legs and a beak that is tipped with black. Similar to other terns the Forster’s tern will fly over the water looking for prey and will dive to capture fish from the surface or just below the surface of the water. Pairs will nest in colonies in marshes with areas of open water. They make their nests on the ground as a scrape and will have 1-4 eggs that will be incubated for 23-28 days. Once the chick hatches it will stay in the nest waiting for food to be brought back to it by the parents. 

Source- https://www.allaboutbirds.org/guide/Forsters_Tern/overview