Return of the Eagle
Bald
Eagle
(Haliaeetus leucocephalus)
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Return of the Eagle Bald
Eagle |
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Two eaglets perch on a nest along the upper Delaware River in New York State, an encouraging sign that this magnificent bird of prey is reclaiming its niche in the watershed. Photo by Peter Nye, NYSDEC |
Despite objections from Benjamin Franklin, the bald eagle was selected as our national emblem on June 20, 1782, because of its long life, great strength, and majestic looks. It is estimated that our national bald eagle population was about 100,000 during the 1700s.
The first major decline in population occurred during the late 1800s. Large numbers of the birds were killed indiscriminately prior to federal protection under the Bald Eagle Act of 1940. The heavy use of DDT and other pesticides, which became widespread by the 1940s, also had a significant effect on the bald eagle population because these chemicals inhibited successful reproduction by making the shells of the eagle eggs too thin to hatch.
By the 1960s a single bald eagle sighting along the Delaware River was rare; this is particularly noteworthy since hundreds of bald eagles previously wintered along the river. Bald eagles are predominantly fish eaters, which is why they build their nests and live near water, and why they migrate to open water areas during the winter months.
Today, the number of bald eagles found nationally and in the Delaware River Basin has rebounded dramatically. One very important reason for the return of the eagle was the federal government's decision in 1972 to ban the manufacturing of DDT in the United States. Programs by the Delaware River Basin Commission and other agencies and organizations to keep the river and its tributaries clean, the fish abundant, and the habitat undisturbed also have been a big help in the recovery of the bald eagle population throughout the basin.
Are bald eagles bald? No, their heads are covered with feathers which turn white as the birds mature. The word "bald" is a derivative of "balde," an old English word meaning white. |
The 120-mile stretch of the Delaware River from Hancock, N.Y. to the Delaware Water Gap is one of the largest and most important inland bald eagle wintering habitats in the Northeastern United States. This is based upon consistency of annual use and the numbers of eagles confirmed to be using the upper Delaware. This region provides areas of open water for foraging and prey (such as fish, waterfowl, and carrion), as well as adequate undisturbed upland areas for perching and roosting . . . all requisites for suitable overwintering habitat. The Delaware River is considered an "essential" bald eagle winter habitat, as specified by the Northern States Bald Eagle Recovery Plan. Preservation of "essential habitat" is considered necessary for the full recovery and long-term survival of this species. The Delaware River also has been nominated as one of the 10 "core" bald eagle wintering areas within the 24-state Northern States region (New York State Department of Environmental Conservation [NYSDEC], 1999), sites where protection must be assured, in perpetuity, as one of the recovery objectives.
Nearly 100 observers counted 573 bald eagles in New York State during the 2008 annual midwinter survey coordinated by NYSDEC. This set a new record for the state's annual January survey and exceeded the 500 mark for the first time since the statewide midwinter count began 30 years ago. The main stem Delaware River (Hancock to Port Jervis) and the Mongaup River Subbasin (which drains to the Delaware) accounted for 87 bald eagles. In addition, the report prepared by NYSDEC Endangered Species Unit Chief Peter Nye noted:
"While flying up the west-branch of the Delaware River immediately below the Cannonsville Reservoir Dam (Delaware County), we encountered more eagles than I have ever personally witnessed in one place in New York State... On our 10 January fly-over of this small stretch of river, so many eagles, primarily immature birds, rose into the air as we passed, that even our mechanical counters had trouble keeping up. The 50 eagles that were counted there that day were surely an underestimate."
The total of 137 bald eagles counted in the upper Delaware watershed of New York State (including the main stem Delaware and tributaries) represented 24 percent of the statewide total. Only 41 bald eagles were counted statewide during the first survey conducted in January 1979. View the NYSDEC annual midwinter survey results between 1990 and 2006.
In the 2005 Midwinter New York State Bald Eagle Survey report, Nye wrote,
"Our observations continue to confirm the importance of these [major NYS] wintering areas, not only to resident New York State bald eagles, but to numerous eagles from eastern Canada (as confirmed by our extensive migration tracking studies). These studies have not only elucidated the migratory timing and pathways of these eagles, but perhaps most importantly, they have demonstrated the long term fidelity of these eagles to these particular wintering grounds. On a landscape scale, these critical wintering habitats are highly specialized and few, requiring concerted attention and conservation by landowners and resource managers in order to ensure their availability into the future."
Additionally, Nye noted in the 2004 New York State Bald Eagle report, "Our observations continue to confirm the importance of the upper Delaware River watershed ... The importance of this wintering habitat to eagles from New York and beyond cannot be overstated." In 2004, nest success along the Delaware River was 100%, with five breeding pairs fledging 11 young (84 breeding pairs fledged a total of 111 young in the state); this success rate and number of young fledged (i.e. reached the age where they can fly and be banded) per breeding pair were the highest of all areas studied in the state.
NYSDEC and the National Park Service are involved in a cooperative study to monitor both wintering and breeding eagles along the upper Delaware River, which provides a border between New York and Pennsylvania. They observed 15 pairs nested in that interstate river stretch in 2008, 13 successfully, resulting in 26 young fledged.
Did You Know? Eagles and other birds have three eyelids. There are two outside eyelids; the bottom is bigger than the top, so they blink up instead of down. The inner eyelid is called a nictitating membrane; it grows in the inner corner of the eye, right next to the tear duct, is transparent, and sweeps across the eye from side to side. Bald eagles hold the record for the biggest bird nest ever built. One nest in Florida was over 20 feet deep, over nine feet wide, and weighed almost three tons! Eagles have special feet with talons, not claws. Why? Talons are designed to carry things. An eagle foot has four muscular toes, powerful enough to hang onto a large fish as it carries it through the air. |
The Pennsylvania Game Commission reports that there were at least 116 active nesting pairs in 31 of the state's 67 counties in 2006, up from 99 in 2005, which produced 134 young. There were only three known nesting pairs in 1980. The Poconos and upper Delaware River region were home to one of the three largest concentrations of eagle nests in the state (21 nests in 2006, or 18 percent of the statewide total).
Bald eagles are not limited to the upper Delaware watershed. According to the New Jersey Division of Fish and Wildlife, 264 bald eagles were counted in January 2008, the largest number since the annual statewide midwinter survey began in 1978 when fewer than 10 were observed. 171 bald eagles, or 65% of the statewide total, were counted in the Delaware River Basin. Southern New Jersey's Delaware Bay region continued to host the majority of the state's wintering birds. The statewide number of active breeding pairs, those which laid eggs, has increased from a low of one in 1982 to 63 in 2008. Most nests were located in the southern part of the state, particularly within about 12.5 miles of the Delaware River and Bay.
Annual surveys conducted by the Delaware Division of Fish and Wildlife indicated that 32 nesting pairs fledged 37 young in 2004, the highest number ever documented in the state. During Delaware's first survey in 1978, only three nests were discovered, none of which were successful.
Hopefully, ongoing bald eagle restoration programs will result in even greater numbers of this living symbol of America's freedom and spirit returning to a river which witnessed a nation's birth.
Explore these great bald eagle links!
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Bald Eagle on the Delaware River Near Narrowsburg, N.Y. Photo by David B. Soete |
Updated: April 22, 2009
Voice
(609) 883 - 9500 ext. 260 FAX
(609) 883 - 9522
clarke.rupert@drbc.state.nj.us