A colleague shared an experience with me. He noted a Black Capped
Chickadee in a lilac bush near his house. It did not fly at his
approach and he was able to pet or stroke its belly. The bird appeared
to be sleeping. After 30 seconds, the birds eyes opened up and head
popped up and it hopped off a few feet. Then flew away.
I suggested that it did not seem to me the bird was sleeping. I
wondered if it had hit a window of the house and was recovering from the
blow. Could a bird sleep so soundly that it would permit such an
approach and touch?