Pittsburgh's pair of bald eagles apparently have a new egg a week after their nest was lost when the tree was toppled by high winds.
After losing the nest Feb. 12, the pair started to build a new nest near the old one in a tree on a hill overlooking the Monongahela River.
The Audubon Society of Western Pennsylvania said Monday that without a clear view of the new nest from a webcam, observers have deduced the presence of an egg by the birds' behavior.
They have taken turns on the nest, not leaving it unattended since Sunday morning. In addition, they lean down once their stand up, presumably to roll the egg and give it a consistent temperature.
It takes 35 days of incubation before an egg can hatch.