Ouroboros Spine on the wing

The last thermals of the afternoon were winding down just as the sun threatened to slip behind a mid-horizon cloud, and a dark speck wheeled downwards in lazy circles. The pinprick morphed into a rangy creature with long, crooked wings and a broad wedge of a tail - a blade of obsidian that cleaved aside the summer haze as she pulled in her flights. It was a casual descent, but she could not help but inject a bit of play into it, and for no reason other than her own amusement, the bird rolled into a stoop and plummeted a hundred feet before unfurling her wings and fanning them to their full extent. She shot upwards on a new trajectory, pulled in again, and carved a new arc deeper than the last. Each successive swoop was more daring until the very tips of the pines quivered within claw's reach, and it was upon one of such lodgepoles that Altai lit and ruffled her windswept plumage with a throaty croak to proclaim her temporary domain.