Coccyzus americanus

"The yellow-billed cuckoo ranges from southern Canada to Mexico. It appears to be declining throughout much of its U.S. range and has been proposed for endangered status in the West. Twelve inches long, it is brown above and white below and flashes rufous primaries in flight. The yellow lower mandible and large white spots on the under side of the tail are diagnostic."

Here is a better view of the tail.

Here is the Yellow-Billed Cuckoo from the Cornell Lab of Ornithology.

Picture taken with a Nikon D80 using a Nikon manual focus 300mm, f/4.5, manual focus lens.