Unusually quiet Koel

This female Asian Koel was up high at the same spot ever since the first moment I saw it, and extremely quiet.  I had guessed that it was waiting for calls from a male, and more than half an hour later, I was proven right.  However, it was not easy then to track the male calling but I did find it eventually amidst rather dense leaves and high up.  And shortly after, the female flew off, strange, not towards the male but away!  A peculiar courtship, if it is one!

And the male which was just a few feet away, amidst thick foliage.