I wasn’t able to find the fledglings from 310 West 72nd Street, but I did see both of the parents on top of 220 Riverside Boulevard.  They were being harassed by two Northern Mockingbirds that have a nest on a penthouse at 71st and West End Avenue.  The rotation of songs sung by one of the Northern Mockingbirds includes an American Kestrel call which confused me to no end until I figured out who was singing it.

I suspect the two fledglings are on top of the roofs of be buildings near the nest.