I've been by Riverside Park a few times over the last week, but haven't seen the fledgling since the 4th of August. I suspect that the fledgling is exploring and is somewhere in a twenty block radius of the nest. Any news of sightings would be appreciated.
Update: August 17th, 2009. Pam Langford was kind enough to send me an email saying that the fledgling was near the 83rd Street Playground on the evening of Sunday the 16th. It was nice to hear the fledgling was doing fine.