I received two great emails. The first was a note from James O'Brien that he ran into someone who can see the 888 Seventh Avenue nest. This person said Charlotte was sitting on eggs. It might turn out that the nest isn't behind the vents after all. This makes 888 the fourth confirmed nest in Manhattan.
The second note was from Glenn Alvarez, who wrote that Highbridge Park has an active Red-tailed Hawk nest. This is the fifth confirmed Manhattan nest for the season!
James O'Brien had seen the nest this winter, from the lower level of Highbridge Park. Glenn's email confirmed the nest was active and gave us the hints to find it from Amsterdam Avenue. Like the Highbridge nest, it may become impossible to find once the trees get leaves.
Highbridge Park is located along the Harlem River on Manhattan's eastern northern tip. It is a long, thin park of about 120 acres. For information about the park, see the Park's Department website.
I went up after work to take some photographs of the nest. I only saw one Red-tail, who I assumed was the female since it was sitting nest for over 90 minutes. I didn't see its mate.