Release #064-12
June 13, 2012
For Information
Contact:
Jerry Feaser
717-705-6541
GAME
COMMISSION RENEWS EFFORT TO PROTECT NESTING COLONY OF GREAT EGRETS AND
BLACK-CROWNED NIGHT-HERONS ON WADE ISLAND
Cull of
cormorants necessary to protect unique nesting area of two endangered species
HARRISBURG -
Pennsylvania Game Commission officials today announced that they, along with
officials from the U.S. Department of Agriculture’s Wildlife Services, have
renewed a program to sustain and protect a historic nesting colony of great
egrets and black-crowned night-herons - two state endangered species - on Wade
Island, a three-acre isle near Harrisburg in the Susquehanna River. This effort
includes the limited culling of double-crested cormorants increasingly hoarding
canopy space on this relatively unique nesting site. Culling was first
used in 2006, and again in 2011.
So far, 90 cormorants have been culled from Wade Island, and there are plans to
remove a few dozen more over the next few weeks. More importantly, however,
great egrets and black-crowned night-herons were seen quickly making use of the
recently vacated trees.
“Wade Island is home to the state’s largest nesting colony of black-crowned
night-herons and great egrets, both of which are on Pennsylvania’s endangered
species list,” said Dan Brauning, Game Commission Wildlife
Diversity Section supervisor. “It isn’t clear what brings these colony nesting
birds to Wade Island. Perhaps it is good food resources in the Susquehanna
River or it’s proximity to the Chesapeake Bay.
Whatever the reason, no other place in the state comes close when comparing the
number of nesting sites of these magnificent birds.
“Unfortunately, double-crested cormorants - also colony nesters - have pushed
their way into the night-heron and egret nesting area, and the nesting activity
of the cormorants has increasingly become a concern. While cormorants were at
one time rare in Pennsylvania, populations have steadily increased. In fact,
populations of double-crested cormorants have been increasing rapidly in many
parts of the U.S. since the mid-1970s, and their abundance has led to increased
conflicts with various biological and socioeconomic resources, including
recreational fisheries, other birds, vegetation, and fish hatchery and
commercial aquaculture production.”
Comparing the latest survey, conducted on May 2, to the survey conducted on
June 28, 2011, the number of great egret nests increased from 103 to 185, and
the number of double-crested cormorant nests increased from 127 to 188.
However, the number of black-crowned night-heron nests dropped from 87 to 67,
during the same time period, and represents the fourth lowest number of
night-heron nests in the 27 years of nest surveys on Wade Island.
Cormorants were first confirmed nesting on Wade Island in July of 1996. At that
time, only a single nest was found. Since then, though, the number of cormorant
nests on Wade Island has increased dramatically.
“Unfortunately, there is a limited number of nesting sites on Wade Island,” Brauning said. “This is a particular problem for great
egrets, which prefer nest locations similar to those used by the cormorants.
Therefore, we have initiated a culling operation by the U.S. Department of
Agriculture’s Wildlife Services to remove cormorants using specialized air
rifles and/or suppressed .22 caliber rifles.”
In 2006, USDA Wildlife Services removed 64
cormorants, and in 2011, the agency culled 40 cormorants.
USDA Wildlife Services has obtained all of the necessary permits from the U.S.
Fish and Wildlife Service to conduct this operation under the direction of the
Game Commission. The state Department of Conservation and Natural Resources
owns Wade Island and has provided approval for this operation. All culled
cormorants that are recovered are being turned over to the Game Commission for
disposal.
Brauning noted that extreme care is taken to not
disturb the endangered species nesting on the island. Culling efforts will be
stopped immediately if it is perceived that activities are threatening the
nesting of egrets or herons.
To ensure public safety, the Game Commission has been providing law enforcement
assistance or arranging for assistance from the Pennsylvania Fish and Boat
Commission throughout the operation. The equipment used is designed to reduce
any risks and is used in the safest manner possible.
Brauning noted that studies have shown when nesting
cormorants encroach upon colonies of other nesting birds, including both
black-crowned night-herons and great egrets, they reduce the amount of nesting
space for those other nesting species. In addition, cormorants have been known
to take over egret nests and also kill trees as a result of their nesting
activity. Several other cases found that cormorant droppings on the leaves and
branches of nesting trees apparently caused egrets to abandon colonies.
Brauning stressed that culling a portion of the
cormorants was not the first option explored, and has been used only twice. He
noted that in 2004 and 2005, the agency attempted to encourage nesting by
egrets and night-herons on neighboring islands. However, that effort was met
with limited to no success.
“Trying to lure some of Wade Island’s herons and egrets to a nearby island was
unsuccessful,” Brauning said. “Egret ‘decoys’ were
placed on an island that neighbors Wade Island with hopes of attracting some
birds away from the growing cormorant population. The use of decoys will
continue, but such efforts generally provide only mixed success and may attract
cormorants as well. Other methods to control the success of the cormorant nests
(oiling of eggs, use of poles and high-pressure sprays) are not possible on
Wade Island, because of the nest height.
“Therefore, lethal removal of the cormorants was determined to be the safest,
least disruptive, most cost-efficient and promising control method.”
In support of this conclusion, USDA Wildlife Services also has considered all
available management options and the adverse effects associated with those
options. Wildlife Services has determined lethal control to be the most
appropriate management option and does not foresee any significant negative
impacts to other wildlife or the public from this option.
“The Game Commission is responsible for managing all of the Commonwealth’s
wildlife species,” Brauning said. “Particular care
must be taken when managing endangered species to protect them from further
reduction and their possible disappearance from the state. Disturbances - or
increasing competition for nest sites - can cause colony nesters to move
abruptly. Wade Island is an extremely important nesting habitat for both the
endangered black-crowned night-herons and great egrets, but the future use of
the island by these two birds is threatened.
“While we recognize that some people will be offended by the lethal removal of
cormorants on Wade Island, we believe it is the best way to ensure the
continued nesting success of the great egrets and black-crowned night-herons
that use this unique nesting area. In addition, the Game Commission will
continue to research and look for other methods to help promote the continued
existence and well-being of these two endangered species and to secure their
future within our state.”
For more information on great egrets or black-crowned night-herons, please
visit the Game Commission's website (www.pgc.state.pa.us),
click on “Wildlife,” then choose “Endangered and Threatened Species,” and then
choose either “Great Egret” or “Black-crowned Night-heron” in the “Endangered
Species” section. A brochure about this project is available on the website at
the top of the “Endangered and Threatened Species” page, too.
To Connect with Wildlife, visit the Game Commission at the following:
Website: www.pgc.state.pa.us
Twitter: www.twitter.com/PAGameComm
YouTube: www.youtube.com/pagamecommission
Facebook: www.facebook.com/PennsylvaniaGameCommission
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