When a nest of American bald eagles hatched this April, they made local and national news as the first observed bald eaglets to hatch in Cook County in more than a century. Now at least one has fledged and is flying around the eagles’ Tampier Slough home.

After the eaglets hatched this spring, their parents immediately began to tend and feed them. In June, Forest Preserve staff, through a thick screen of leaves surrounding the nest, could barely make out juveniles, by then much larger and test-flapping their wings. In late July, at least one confirmed juvenile bird finally took the plunge off the eagles’ tree and learned to fly—a sometimes harrowing experience known as fledging.

Juvenile bald eagles can be distinguished from their adult parents by the absence of the trademark white (“bald”) head and white tail feathers. The all-dark juveniles won’t have the classic bald eagle look until year four or five, though they may appear mottled with white in years two and three.

The extreme heat this summer added to the long list of challenges young eagles face, but at least one, and possibly more, persevered. In nests elsewhere in the county, Forest Preserve staff have observed juvenile ospreys, another large raptor, to be several weeks behind in development. The same may have been true of these eaglets.

All of the Tampier Slough eagles are now busily fattening up for the winter. Depending on conditions, they may stay close or migrate to ice-free climes farther south.