She's got a significant head start; he moves faster than she does. Which means that he's cut the distance between them to something like a quarter of a mile, by the time the sun has made its way free of the horizon.

Which in turn means he's close enough to hear it when a shriek rends the air from some distance ahead, sending clouds of birds winging hastily into the sky.

A second shriek follows, this time with words in it: "No! No!"