Sarah Milbourne presents a bald eagle at the Eagle Festival.

CHURCH CREEK — On Saturday, Sarah Milbourne of the Maryland Park Service led a program at the big white tent at Blackwater, as part of the annual Blackwater NWR Eagle Festival. She asked an audience of adults and children,”How many of you have seen an eagle in the wild?” Lots of hands went up, in fact, just about everyone.

Forty years ago, very few would have raised their hands. Few would have gotten to spot an eagle soaring over the lakes and rivers of Maryland where they had once been plentiful. The large wingspan of a soaring eagle in Maryland had become a rarity. Today, Sarah Milbourne joyfully explains how 40 remaining nesting pairs in the 1940s have gone forth and multiplied. Our national symbol now accounts for 600,000 nesting pairs, with 600 of them in Maryland.

Naturalists credit Rachel Carson and her book Silent Spring for government action and the banning of DDT. In her book, Carson made the connection between the eagle’s pending extinction and DDT. In terms even young children understood, Ranger Milbourne explained how the popular pesticide was considered a boon to agriculture. But the poison leached through the soil, into the waterways, and into the fish, which were the eagles’ diet. The result? Eagles produced an egg with a shell so thin it cracked on the weight of the nesting parent. The rangers in the show tent on Saturday used weights and chicken eggs to demonstrate the vulnerability of the eggs, No viable eggs? No eaglets.

The 17th Eagle Festival provided other demonstrations and exhibits with owls and hawks. The entire reserve turns into one of the finest science classrooms in the country. Visitors were able to make a guided tour through the park in buses and vans and see eagles, but they checked on other varieties of waterfowl as well. Volunteers also explained the care that injured rescued birds receive. Bob Baltz, a volunteer, says that besides nutrition, the raptors get a spa treatment that means “weighed and sprayed,” and “pedicures too!” Those talons have to be trimmed. Nonetheless, the rangers and volunteers like Bob Baltz say they still get scratches and bites, but they love what they do. Sam Dixon, a hawk handler, started out as a young volunteer and enjoyed it so much that it is now her career.

The festival includes activities that challenge children, and many youngsters at the festival are regulars. Thirteen-year-old Josh Villanueva is a repeat customer. He says, “My family and I come every year. I like science and I learn new things here.”

For others with similar interests, opportunities exist at the parks and refuges. You can help count nests, watch a nest, and be part of the Maryland Bird Conservation Partnership.