If you drive along or float on the Delaware River today, chances are that you would see at least one bald eagle, and probably more. 

Eagles, taken for granted by many people today, can be seen in almost every area of the region, and all the counties that comprise the region have several occupied bald eagle nests. During the winter, many eagles are seen in the area; some of these eagles are migrants from Canada, but many are adults and immature eagles from local nests.

This wasn’t always the case here; the effects of DDT caused eagles, as well as several other bird species, to experience reproductive difficulties in the form of thin and brittle eggs that would not endure the incubation process. In the late 1970s, Pennsylvania was down to three breeding nests and New York was down to a single breeding pair that could not reproduce due to DDT effects before the chemical was banned. The bald eagle was on the verge of extirpation (local extinction) in NY and PA, and there were no nests within our region.

In 1976, New York State initiated a bald eagle reintroduction program where eaglets from Alaska, which had a plentiful population of eagles, were placed in cages on man-made elevated nesting platforms called “hacking towers.” Eaglets were fed by people who stayed out of view of the birds so the eaglets did not “imprint” on humans as a parent. 

When the eaglets were around 12 weeks old, the outside parts of the cages were opened so the eaglets could perch on branches placed on the cages and eventually make their first flight, or fledge. 

Four years later near Watertown, NY, a pair of these “hacked” eagles were found successfully breeding at a nest of their own. 

In 1980, the NYSDEC went large-scale with the project, hacking close to 200 eaglets during the next nine years. Pete Nye, the NYSDEC biologist who spearheaded the NY restoration effort, explains it here: vimeo.com/73593168.

Pennsylvania initiated its own reintroduction in 1983.

This is a graph, starting when breeding eagles were first observed during 1993, which shows the first 15 years of breeding eagle pairs in the upper …

The Upper Delaware Scenic and Recreational River comprises 73 miles of river from Hancock, NY to just below Cherry Island at Sparrowbush, NY. This is prime habitat, with many undisturbed areas, many potential nesting locations and a plentiful uncontaminated source of food for the fish-eating bald eagle. It took close to a decade from the time the first hacked eagles reached breeding age until the first pair of bald eagles established a territory within the Upper Delaware area; eagles typically establish a nest and take a mate within 50-100 miles of their natal nest (where they themselves were raised). 

The spread of eagles was slow at first, and perhaps some of the earlier territorial eagles in the area could have originated from the PGC hacking facility that was initiated in 1983 at nearby Shohola Lake in Pike County, PA. The first occupied pair appeared in 1993 along the river, but they did not produce young for the first two years—typical of some newly mated pairs.

The number of bald eagle pairs increased slowly but steadily over the next 30 years to the point that 21 breeding pairs were estimated to be active by 2023. Eagles utilized more river territories, and some eagles had bands that they received when they were young and were banded in a river nest during NYSDEC nest surveys. 

In some cases, the distance between the natal nest and that young’s new territory was five miles or less. 

Eagles reach breeding age at four to five years, and newly established territories by banded eagles have shown that they tend to get started young. Five- to seven-year-old eagles were the norm for banded eagles and a four-year-old female was observed establishing a new territory with an older male (unbanded, but showing four-year subadult plumage). 

It is impossible to determine the age of eagles by sight once they molt to full adult plumage at five years or so of age, so band resights by birders or photographers are very valuable.

The Upper Delaware Scenic and Recreational River has proven its worth for bald eagle habitat. Even before eagles started to breed along the river, winter visitors from Canada were utilizing the river for a winter food source while their own breeding habitats were frozen completely over. 

For the estimated 21 resident eagle pairs as of 2023, the immediate threat is habitat loss; we as a people can work as partners and stewards to minimize this threat. 

As I watch an eagle in flight, I stand in awe of nature’s perfect airframe. Watching an eagle soar in a thermal, we can see a circle of motion; we are fortunate to live in an area where we are able to observe this winged one’s circle of life.