Nightwings
It was Avluela the Flier's scarlet and ebony wings that led the Watcher to the seven hills of the ancient city, leaving the skies and deep space unguarded. And so the invaders came and conquered and Avluela became lost in the turmoil.
Fiction in English, Fiction, Science Fiction & Fantasy, Hugo Award Winner, award:hugo_award=1969
Robert Silverberg, Michael Netzer
Robert Silverberg is an American author, best known for writing science fiction. He is a multiple winner of both the Hugo and Nebula Awards.

Silverberg received a Nebula award in 1986 for his novella Sailing to Byzantium, which takes its name from Yeats' poem; a Hugo in 1990 for Enter a Soldier. Later: Enter Another; and in 2004 he was named a Grand Master by the Science Fiction Writers of America.

([Source][1])


  [1]: http://en.wikipedia.org/wiki/Robert_Silverberg