As the trio approached, more than a hundred feet into the clearing, the bird's head snapped onto their location, enormous eyes focused on them. A DC 37 PErception check would notice that it was noticing<em>him</em>even through the invisibility, as well.<br/><br/>If the group persisted on approaching, once they drew another hundred feet in, the bird spread its wings, and lifted off the stone pillar, enormous wings beating intensely, as it gained a little height, then began to dive.