I received the report from JumpFlapper who witnessed the event with other Hawk-watchers in Washington Square Park today.
Rosie and Bobby were seen copulating on the Judson Memorial Church cross at roughly 3:50PM today.
This is very exciting news. I hope they mate (or have been mating) often so the chance of them having a successful brood in the spring increases manyfold.
One of my Hawk-watching friends generously shared photos of the event for me to post (anonymously) and show you. They are incredible! Thank you!
In the photo below, you see Rosie awaiting Bobby's arrival:
She turned her tail feathers to the side to accommodate him:
The copulation lasted only a few seconds (as is normal):
My friend reported they were also seen copulating where Rosie had picked plant nesting material on Saturday. That copulation wasn't photographed but you can see Bobby and Rosie seated together in that spot today: