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William Miller


                 Eagles                        Bald

                 16 v The Maryland Natural Resource v
                                                                             ETERNAL SYMBOLS OF
                                                                             THE CHESAPEAKE
                                                                                            by Glenn Therres
                he Chesapeake Bay, the                          bald eagles are similar in size but        consistently has the largest populations,
                world’s second largest                          have brown heads and tails, obtaining      ranging from 70 to 225 individuals.
                estuary and home to a                           their adult plumage when they are 4½       Unfortunately, there is no public access
rich array of fish and wildlife species,                        years of age. Some immature eagles         to this U.S. Army facility so viewing is
is known far and wide for its blue crabs,                       are mottled on their undersides with       restricted to base personnel. The best
oysters and striped bass (locally known                         white feathers.                            place to view bald eagles is Blackwater
as rockfish). It is also revered as a major                       Maryland’s wintering eagles are most     National Wildlife Refuge, where miles of
wintering ground for a multitude of                             often seen perched alone in trees while    roads provide visitors with unsurpassed
North American waterfowl – great                                looking for food or warming themselves     views of the approximately 100 eagles
flocks of Canada geese, ducks and                               in the sunlight. However, there are        that overwinter there each year. At the
tundra swans migrate to the region to                           several locations throughout the Bay       top of the Bay, along the Susquehanna,
spend the colder months on the open                             area where concentrated numbers of         public access is also available below
waters and tidal marshes of the Bay and                         eagles occur, upwards of 25 to 300 birds   Conowingo Dam. Most of the eagles
its rivers. Close on their heels come the                       at any one time. In Maryland, major        using these “fly-in communities” are
bald eagles, traveling to the Tidewater                         concentrations are found at Blackwater     migrants and immature birds.
region from all across the eastern part                         National Wildlife Refuge in Dorchester
of the United States.
   Each year thousands of bald eagles
                                                                County, Aberdeen Proving Ground in
                                                                Harford County, and along the lower
                                                                                                           The Eagle Has
take to the treetops along the Bay’s                            Susquehanna River below Conowingo          Landed
shores and major rivers, including                              Dam.                                       Many bald eagles that overwinter in
the Potomac, Patuxent, Susquehanna,                                                                                           the Tidewater area
                                              George Jett (2)

Choptank, Chester and Nanticoke                                                                                               also nest here; in
Rivers. They can also be spotted further                                                                                      fact, they start their
inland, roosting near reservoirs, lakes                                                                                       nesting season during
and ponds, provided they have not                                                                                             the coldest months of
frozen over.                                                                                                                  the year. The birds
   Why do the birds come to the                                                                                               mate for life and
Chesapeake area for the winter? Bald                                                                                          by mid-December,
eagles feed primarily on fish, ducks                                                                                          have already started
and other aquatic creatures. When                                                                                             courtship rituals and
waterways freeze over in eastern                                                                                              nest building. Most
Canada, Maine and New England,                                                                                                of Maryland’s nesting
their prey is no longer available -- fish                                                                                     eagles are found
are under the ice and ducks move                                                                                              within a mile of tidal
south. Maryland’s waterways do not                                                                                             water, although a
freeze regularly so there is usually                                                                                           few pairs nest inland
an abundance of fish and waterfowl                                                                                             along the upper
– providing the perfect cold-weather                                                                                           Potomac River and at
oasis for eagles.                                                                                                              the major reservoirs.
                                                                                                                               Today every county
Following the Flocks                                                                                                           in Maryland has at
Anyone who spends time near tidal                                                                                              least one nesting
waters or other big bodies of open                                                                                             pair.
water during the winter months has                                                                                                A huge nest of large
a good chance of seeing an eagle.                                                                                              sticks is constructed
Large and imposing birds of prey,                                                                                              in the upper crotch of
eagles stand nearly 3 feet tall with a                                                                                         a tree, usually along
wingspan of 6 to 7 feet. They appear                                                                                           the edge of a forest
almost black in color when in fact they                                                                                        or shoreline. Eagles
are dark brown. Adults are most easily                                                                                         will usually select
recognized by their prominent white                               Since 1979, surveys have been            the largest in the area, since it needs to
head and tail, and their bills and feet                         conducted of eagles wintering at           serve as a vantage point and support a
(called talons) are yellow. Immature                            these concentration areas. Aberdeen        nest that is three to four feet deep and

                                                                                                                                 Winter 2007 v 17
P.M. Lynch

                                                           off food and guarding the nest from        federal and state endangered species
                                                           nearby trees.                              acts mandated that our national
                                                                                                      bird be left to nest undisturbed by
                                                           A Success Story of                         human activities. The population
                                                                                                      has been proposed as fully recovered
                                                           Patriotic Proportion                       throughout North America, and the
                                                           Today there are over 400 nesting pairs     bald eagle now serves as an excellent
                                                           of bald eagles in Maryland and over        symbol of endangered species efforts,
                                                           900 in the Chesapeake Bay region,          having been saved from the brink of
                                                           including Virginia, southeastern           extinction.
                                                           Pennsylvania and Delaware. However,          The eagle’s heralded comeback in
                                                           these numbers were not always so           the Chesapeake region would not
                                                           high: In 1967, the majestic bird was       have been possible without a total
                                                           added to the federal Endangered            commitment to restoring a balanced
                                                           Species list. By the early 1970s, the      environment, complete with an
                                                           bald eagle population throughout           abundance of prey and safe nest sites.
                                                           the lower 48 states had declined           Ongoing efforts to restore the region’s
                                                           dramatically due to the effects of DDT     water quality have also benefited the
             six feet or more in diameter. Loblolly        and other organochlorine pesticides,       species, and their recovery is a clear
             pine, oaks and sycamore are popular           which adversely affected reproduction      indication of overall improvements
             choices commonly found along Bay              rates by causing the bird’s egg shells     to the health of our waterways. An
             shorelines.                                   to be too thin to incubate successfully.   eternal symbol of the Chesapeake
                Females lay one to three eggs between      Aerial surveys conducted in 1977           region, the indomitable bald eagle
             late January and early March. On the          documented only
                                                                                George Jett

             lower Eastern Shore and in southern           41 nesting pairs
             Maryland nesting pairs lay their eggs         statewide.
             in late January, while along the upper          After the federal
             Bay and inland, egg laying occurs in late     government
             February or early March. The females          legislated a
             will then incubate the eggs for 35 days,      nationwide ban on
             with the male occasionally taking over        the use of these
             to allow her to stretch and do a little       pesticides, eagle
             hunting.                                      populations around
                Eggs generally hatch in March and          the country slowly
             April and the young will spend the next       started to increase.
             12 weeks in the nest until they fledge        In Maryland, the
             in late May or June. Upon hatching,           number of nesting
             the eaglets are covered in gray down,         pairs topped the 100
             little more than puffs the size of a tennis   mark in 1990 and
             ball; their feet are the largest part of      just six years later, over 200 pairs of    has once again returned to its rightful
             their body. An adult must brood the           eagles were nesting statewide. In 2002,    perch at the top of the Bay’s food
             chicks to keep them warm during these         the breeding population exceeded 300       chain. v
             early days to protect them from the           for the first time since the 1930s.
             early spring’s chilly temperatures and        Similar trends in bald eagle breeding
             April showers. As the chicks grow and         numbers occurred nationwide during
             develop feathers, the adults will spend       this time period.                          Glenn Therres is an Associate Director
             less time on the nest and more time             The recovery of the bald eagle is        for DNR’s Wildlife and Heritage Service.
             hunting in order to feed them. At five        proof positive that with appropriate       He oversees the Natural Heritage Program
             weeks of age, the young are the size          management and protection it is            which is responsible for the conservation of
             of a crow; by the time they are 11 to         possible to reverse the impacts of         the state’s endangered species and wildlife
             12 weeks old, they have reached adult         human actions upon our nation’s            diversity. Among his varied duties, Glenn has
             size. By then the parents spend very          wildlife. In addition to the ban on        served as the state’s bald eagle biologist since
             little time in the nest, merely dropping      DDT, protections afforded by both the      1986.

             18 v The Maryland Natural Resource v

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