Well, I sat with a lady on a park bench in front of the boating pond and we discussed why Lola hasn't hatched any eggs. Lola's nest is above the middle window at the top floor of this Fifth Avenue residence building facing onto Central Park. Lola and her mate, Pale Male, are the famous red-tailed hawks, the breed that mates for life. Lola has not had eggs hatch out for a few years.
The woman thinks - and perhaps it is a very good point - that there is a metal frame device above the window and because of this the nest isn't resting on a solid surface. Instead, it is poised above the shelf and air can circulate below the nest. Possibly this is why the eggs can't be kept warm and develop as they should.
The telescopes were positioned just so and Pale Male could be seen inside the nest.