I spent 20 minutes watching Bobby relax in the park trees until he caught sight of a juvenile Red-tailed Hawk. He shot right toward it and chased it away from the park, forcing it northward.
Juvenile on the left, Bobby on the right:
The juvenile made high-pitched cries as it flew near Bobby.
I never got to get a good close-up of the juvenile before it and Bobby flew out of sight.
I had to go for the day but a fellow Hawk-watcher saw a juvenile flying above and around the park about 45 minutes later while Bobby perched on his One Fifth Avenue perch.