A fellow Hawk-watcher spotted Rosie and Bobby gathering lots of nesting material and bringing it to the nest yesterday.
Today I got to see Bobby perching from place to place then swooping down and catching a pigeon. He was then harassed by a pair of Mockingbirds while he tried to eat.
Seen beyond the tree in flight from one perch to another:
Freshly-plucked pigeon feathers floating down: