I watched these two birds continually go at one another among the thousands of terns nesting in this location and finally, managed to catch a shot of the two together. Common tern is on the upper left and the roseate is lower right.
Certainly not perfect, but it was an interaction shot which captured what my eyes had been watching......
What I like best here is the eye contact between the two. Great interaction! If you could add a catchlight (or better, enhance an existing one if any) on the top bird this would be near perfect!