http://glaromaps.ducks.org/blackduck/

JF Griffin - Index

JF Griffin - magazine - Index

American Black Duck
Research Takes Flight
in New Jersey
By DAne cRAMeR, University of
Delaware, Research Assistant
and
PAUl M. cAsTellI, new Jersey
Division of fish and Wildlife,
Research scientist II
When the autumnal equinox looms
closer and daylight wanes, New Jersey’s
coastal marshes fill with wintering
American black ducks as they have
done for eons. The period of time
between this southward migration
and their farewell bid in the spring
when they return to their northern
breeding grounds is a vital stage in
their life cycle.
Here in New Jersey, a winter salt
marsh scene would not be complete
without a show of black ducks dancing
into a cold northwest wind, floating
effortlessly on silver-lined wings. In
fact, more black ducks winter in New
Jersey than anywhere in the world.
To gain a better understanding of
this critical period in the black duck’s
life cycle, several major studies are
underway in New Jersey as well as
other parts of the birds’ wintering
range.
Along the Atlantic flyway, black
duck numbers have suffered longterm
declines. Interestingly, black
duck numbers in New Jersey have
A VHf radio transmitter is affixed to a black duck hen.
Brook Hill
Paul castelli holds a satellite radio - tagged black duck on the forsythe nWR.
remained relatively stable following
1970s legislation that protected salt
marsh habitat. In other states where
coastal development persists, habitat
degradation and loss resulted in a
continued decline in black duck
numbers. New Jersey provides a
critical area for wintering black ducks,
approximating the center of the birds’
wintering range. According to the Midwinter
Waterfowl Survey coordinated
by the U.S. Fish and Wildlife Service,
nearly half of the Atlantic flyway’s
black duck population winters in New
Jersey.
To set population and harvest
goals and determine priority areas for
restoration and protection, biologists
must understand the habitat and
nutritional requirements of wintering
and migrating black ducks. Toward
this end Ducks Unlimited Inc. is
coordinating a large multi-study
cooperative project. In addition to
the Division of Fish and Wildlife the
study now involves four state wildlife
agencies, two major universities,
four national wildlife refuges, and
numerous sportsmen’s organization
(see sidebar page 77) across both the
Atlantic and Mississippi flyways.
Identifying Critical Habitats
Satellite transmitters attached to
hen black ducks are used to identify
important connections between
wintering, migration and breeding
habitats at the flyway scale.
Satellite transmitters are a relatively
new technology that uses GPS (global
positioning system) technology to
report duck locations to satellites,
which relay the information directly
to the researcher’s desk. These solar-
Follow the Black Ducks!
Visit the Ducks Unlimited Web site to learn
more on black duck research spanning the
Atlantic and Mississippi flyways and for
updates on black duck studies currently
underway.
www.ducks.org/blackduckstudy
Once there, click “follow the Ducks” to
watch the movements of birds fitted with
transmitters right here in new Jersey. Or go
directly to the map with this link:
glaromaps.ducks.org/blackduck/
powered transmitters can last up to
three years.
On the local scale, determining
areas most important for black
ducks wintering in New Jersey is
accomplished by securing standard
VHF radio transmitters to the birds.
Using specialized monitoring
equipment, with direction-finding
antennas, researchers are able to
receive a beep tone emitted by the
birds’ radio transmitters. Locations
are recorded twice daily throughout
the wintering period, day and night,
for birds up to two miles away. These
data are used to calculate winter home
range and habitat use statistics.
76 | New Jersey Fish & Wildlife Digest Buy your license or permit online at August 2008
2008 Hunting and Trapping Issue www.NJFishandWildlife.com
Tina Yerkes, Ducks Unlimited