Forrester’s Tern and Royal Tern. These two terns sitting on the same sand spit allows their size to be easy compared. The Royal Tern is a large tern with a black head and an all orange bill. By contrast, the Forrester’s Tern also has a black head but it is smaller than the Royal Tern and there bill is orange and black at the tip. The Royal tern’s black head characteristically has a “bad hair day” with feathers sticking straight out the back.