Nighthawks are pretty cool birds. On summer nights in the Midwest they make a frog-like chirp and careen through the sky catching insects. They have huge eyes with the same tapetum lucidum as a cat and this allows them to see in the dark. Stiff bristles hang down from the upper beak to protect their eyes from a struggling meal.
Whip-poor-wills and the Common Poor-will are part of the same family of birds. The Poor-will resides in the western part of North America, and is the only bird to hibernate. During cold stretches of the winter, as long as three months, the Poor-will hides in a rocky nest and lowers its temperature to survive. Similar behavior to bears.
The Sleeping Bird series draws its name from these nocturnal avians. The reasons become evident as the story unfolds.