Beyond aforementioned families and orders, other types of birds are taken relatively infrequently. Usually moderate to low numbers of water birds are taken of any variety. About 5 species each of duck and heron, a dozen species of shorebird and a smaller assortment of grebes and rails are known in the prey spectrum. Even among water birds, nonetheless, a wide diversity may be taken, from the tiny least sandpiper ("Calidris minutilla") to an adult mallard ("Anas platyrhynchos") estimated to weigh when taken. Adult ducks and herons of roughly equal weight to Cooper's hawks and other largish adult water birds including ring-billed gulls ("Larus delewarensis") and American coots ("Fulica americana") are sometimes tackled by these hawks. Particularly frequency was recorded of cattle egrets ("Bubulcus ibis") in north Florida, where the egrets were the fourth most regularly recorded prey species. Assorted families of land birds are fairly rare as reported in food studies, including some nightjars, trogons, swifts, kingfishers, parrots and assorted other raptorial birds.