The Harmar bald eagles, Sophie and Andy, are believed to have dropped an egg early Thursday in their nest on the Route 28 hillside.
Gina Gilmore, a Fox Chapel photographer who has been documenting the birds for 12 years, said all indications lead to the presence of an egg in the nest.
“You can track the behavior of the eagles and there’s no reason on Earth that Sophie would be wiggled into that nest continuously, not leaving,” Gilmore said.
The Harmar bald eagles built their current nest in a Sycamore tree in 2014 and have had a successful breeding track record.
Gilmore said Sophie’s persistence in remaining perched in the nest is a tell-tale sign that an egg is inside.
Other telling behaviors include the bird pair carrying in fluff (nesting material) in previous days to bulk up the nest.
Gilmore said she checks on the eagles multiple times a day. Last night, she captured a video of the male bird sitting just outside the nest and the female, with her talons stretched on either side, hovering above it.
“That behavior, to me, says it all,” Gilmore said. “She got up, let out a little scream and looked down, hovering over the nest. She rocks back and forth, getting into the bowl so she can get down low and then wiggles on top of the egg.
“It’s warm out. Those birds don’t want to sit still so if she’s sitting there and not leaving, that says that we have an egg.”
Typically, the parents will incubate eggs around-the-clock for 35 days until they hatch. The female will alternate nest duty with the male, who forages for food to feed the female.
The last week in February and the first week in March have traditionally been when the Harmar eagles have laid their eggs, according to the Audubon Society of Western Pennsylvania.