Hawkmistress!

Description for HAWKMISTRESS! by Marion Bradley Zimmer:

She had rejected her noble birthright and embraced the freedom only a man could claim. She was Romilly who lived among the beasts of hill and forest and communicated with them, who tried humanity and turned it down for its evils and jealousies. She had the MacAran Gift, the rare laran that conferred mastery over hawk and horse.

There was war in the lands of Darkover for this was the age of chaos when usurpers took the throne and the true king wandered in disguise with a price on his head. Romilly wanted none of all this, but there were those who shared her talents--the men and women of the Towers. And for them, Romilly was the key.

Whether male-garbed or beast-minded, she was also human. And duty to her own true kind pointed her to the ultimate decision.