One lane, where's the passing place?

Just after I snapped this pic, both guys jumped down. We thought the bigger one had triumphed, but minutes later, it was the lower little guy who came back to perch. I think it is a pregnant female. At first I thought they just needed the upper leaves as a shade umbrella. I thought it very strange that all the middle stems and leaves were stripped; wondered what was eating the plant because the top and bottom seemed healthy. Don't know whether they just found a convenient place to perch or whether they are responsible for the stripped leaves?