[bloomingeek]

What little experience I have is this: If a coop or other protective area isn't available at night, chickens will roost in a tree until daylight. (their vision is very poor in the dark, so running to escape isn't a real option at night.) The problem with tree roosting at night is owls or other night predators. The owls will position on the trunk side of the limb and side-walk the chicken towards the end of the limb until they fall to the ground, and then well, you know.

A friend of mine always checks his small flock just before dark for escapees from the coop. If the count is off, he always looks in the near-by trees.