Canada Geese at
Blackwater National Wildlife Refuge:
The Arrival
The advance guard arrives in late September, and numbers
steadily increase
throughout October until the current peak concentration of 35,000 is
reached
in early November. About 25,000 geese remain at Blackwater all winter,
while others use the refuge as a resting and feeding area on their way
farther south.
Although it is hard to imagine the refuge without Canada
geese, between
1933 and 1938 none wintered on Blackwater. Goose concentrations on
the Delmarva Peninsula began increasing in the 1940's due to an
increased
food supply resulting from the widespread adoption of the mechanized
corn 
picker that "wasted" much more
grain than was left in the fields when corn
was harvested by hand. From a maximum of 5,000 geese in 1942, the
populations increased at Blackwater until they peaked at 105,000 in
1963.
Due to the significant loss of wetlands and thousands of acres of
three-square
bulrush marshes, drought conditions, reduction in the refuge's cropland
acreage, severely depressed reproductive success on the breeding
grounds,
and increased hunting pressure on the Eastern shore, the Canada goose
population
declined to approximately 20,000 by 1992. Recent improvements in
management practices, however, are helping to restore numbers to our
objective
level of 50,000.
Blackwater Management
In conjunction with the North American Waterfowl Management
Plan, Blackwater
NWR is directing its management effort towards maintaining and
improving
habitat to help restore diminishing waterfowl populations. Over 12,000
acres of natural brackish marsh and open water provide resting and
feeding
areas for migratory waterfowl. The primary plant species in these
areas highly valued for food for Canada geese is the Olney three-square
bulrush.
Since 1992, more than 460 acres of croplands have been
annually managed
to provide a diversity of food sources high in carbohydrates for energy
and in proteins for molting, juvenile body growth, and to help
waterfowl
return to the breeding grounds with sufficient reserves for
reproduction.
refuge-planted crops high in fat-building carbohydrates include millet,
soybeans, sorghum (or milo), corn, and buckwheat; several types of
clover,
winter rye grass, and winter wheat provide excellent sources of green
browse.
Natural vegetation is also provided as a food source through
a
program called "moist soil management." Water is gradually removed
from approximately 300 acres of freshwater impoundments in the spring
to
provide a wet seed bed for germination of natural vegetation. The
plants also harbor higher insect populations which, when flooded in the
fall, provide important protein sources for feeding waterfowl.
Feeding Habits and Movement
Geese feed on tender shoots and roots of aquatic plants in
the marshes
and on grain and "green browse" in the fields. An adult goose needs
an average of one-half pound of food a day - less in warm weather and
more
during cold periods and prior to long distance flights.
In extreme cold and wind, geese will sit out the weather and
not eat.
They save energy by not flying. While waiting, they tuck their feet
and bills into their soft down feathers. Extremities which are not
covered with insulation lose heat rapidly and deplete energy reserves
needed
for migration, nesting, and molting in the spring.
When daytime hunting pressures in the area surrounding
Blackwater are
heavy, the geese often resort to feeding at night when the moon is
full,
returning to the refuge and its marshes during the day. This explains
why there are days when there appear to be no geese here; during these
periods sizable goose flocks are usually only seen at dawn and dusk.
Physical Characteristics
The color patterns of a Canada goose are so distinctive that
it is almost
impossible to confuse it with any other species. The head, bill,
neck, feet, and tail are black, while the cheek patches, which meet
under
the white chin, are its most easily recognized characteristic. The
upper parts are grayish-brown, with the underparts lighter and becoming
white near the tail.
It is not easy to distinguish a gander (male) from a goose
(female).
Generally the gander is acknowledged as the larger of the pair, and he
has a deeper sounding call.
At Blackwater, the average Canada goose weighs about 8
pounds, but their
weights may range from a small 6 pounds to over 15 pounds for an older
bird. The wingspread varies from 5 to 6 feet.
Canada geese held in captivity often live 20-40 years, but
the geese
who migrate to Blackwater probably live an average of 5 to 10 years.
Nesting and Family Life
Geese form very strong, lasting social bonds. A pair usually
mates for
life, although when one dies, the other remates. Some Canada geese 
nest for the first
time at the end of their third year. They usually
lay 5-8 eggs requiring about 28 days of incubation. The proud parents
are very protective of their young goslings. Family ties remain strong
throughout the first year.
While most Canada geese go north to nest, some resident geese
remain
at Blackwater where the young broods may be seen in early summer.
This flock of resident Canada geese began with injured adults who could
not migrate and stayed to raise their families at Blackwater. However,
the resident geese have multiplied and become pests that often destroy
crops planted for the migratory waterfowl.
Migration
There has been much speculation as to what causes the geese
to begin
their spring and fall migrations. The increasing or decreasing length
of days, combined with weather conditions and other variables, motivate
the geese to migrate twice yearly. Fat deposits accumulate just prior
to migration and provide energy for the long flight.
The usual "V" formation provides each goose (except the
leader)
with favorable air currents in which to fly. Older geese alternately
share the lead position. Geese have been observed at altitudes of
29,000 feet, although the normal migration altitude is only 3,000 feet.
Departure
Most of the Canada geese wintering at Blackwater NWR and
other areas
of the Eastern Shore travel north in the spring. The flocks begin
moving out in late February and most are gone by mid-March. From
here they travel to their ancestral nesting grounds on the Ungava
Peninsula
near James Bay, Canada. There, during the summer months, they nest
and rear the young - only to begin the cycle once again with their
return
to southern wintering grounds in the autumn.
Resident Canada Geese FAQ
- What are resident Canada Geese?
Resident Canada geese refer primarily to local breeding Canada geese
which nest and raise their young in Maryland, and more specific to this
proposal, in southern Dorchester County. Resident Canada geese do not
migrate to northern Canada, but remain in southern Dorchester County
year-round. The geese became established on Blackwater Refuge from
released captive and injured birds.
Resident Canada Geese are rapidly increasing in numbers throughout the
Northeast region and are creating significant management problems in
the entire area.
- How many resident Canada Geese are here on the refuge?
These semi-domesticated geese reproduced well, in fact too well. The
population has risen from 350 in 1989 to more than 5,000 this year.
Despite efforts to discourage the resident geese, they are reproducing
at the rate of at least 2,000 new birds a year. The population is
expected to continue to increase.
- How do the resident Canada Geese damage the refuge?
The primary damage is caused when too many geese continually feed in
the same areas. They are so voracious, eating both newly-planted crops
and marsh plants, that they literally strip areas barren of all plants.
Approximately 40% of the refuge’s corn fields were lost to goose
depredation this year. Newly planted ladino clover fields along the Key
Wallace Road corridor have been heavily damaged. Moist soil vegetation
in the refuge’s impoundments are heavily browsed. Regenerating marsh
vegetation around the Wildlife Drive, already damaged by nutria and
snow geese, has been damaged significantly.
These areas provide critical forage for the refuge’s migrating and
wintering waterfowl. In the past several years, it has become apparent
that these areas are becoming so badly damaged or when their
productivity is significantly reduced, the refuge doesn't have enough
wintering habitat to support its 35,000 migratory Canada geese, 7,500
snow geese, 1,500 tundra swans, and 25,000 dabbling ducks. These
resident geese are creating a situation where the refuge cannot achieve
the purpose for which it was established.
In addition, their fecal droppings concentrate in pools of water
created during impoundment drawdowns, and thereby degrade overall water
quality and increase the potential for human and avian diseases
transmitted by fecal material. Droppings on the driveways and parking
areas near and around the Visitor’s Center can become so concentrated
as to create a safety hazard for walking.
It is important to note that the refuge is not the only area
experiencing this damage. Several other property owners are also
reporting damage of crops and marshlands due to resident Canada geese.
- What is the refuge now proposing to do to manage resident
Canada Geese?
Under the proposed Integrated Wildlife Damage Management (IWDM)
program, lethal and non- lethal methods will be used to manage the
adult resident Canada Goose population. It is important to remember
that IWDM would involve a combination of techniques, including: (1)
altering habitat; (2) fencing; (3) use of frightening/harassing
techniques; and (4) population reduction through lethal control
methods. The refuge staff would tailor methods to meet the overall
objective of reducing and maintaining the refuge resident Canada goose
population to the 1989 level.
Lethal control has become necessary as the refuge has conducted
nonlethal methods for several years without success to control resident
Geese populations. Resident gosling production on the refuge in 1998
and again in 1999 exceeded 2,000, despite the expenditure of at least
one full staff year of effort and thousands of dollars for
harassment/scare devices each year. These harassment/scare devices
include: the use of propane cannons, balloons, flags, shell crackers,
etc. None of these devices, or combinations of devices, prevent
resident Canada geese from entering these areas.
When necessary, refuge staff would also live trap resident geese, and
transport them to a certified processor. In accordance with Maryland
DNR's policy, the processor would euthanize the geese, and the meat
would be donated to a charitable organization for human consumption.
These control methods would be timed to avoid conflicts with returning
wild flocks of migratory Canada geese. This is probably the first new
action under IWDM the refuge will take this summer.
- When would live-trapping occur?
If the Service adopts the IWDM program, the live-trapping would occur
sometime prior to the arrival of wild flocks of migratory Canada geese.
Live-trapping will be most effective during a limited number of weeks
when the resident Canada geese are in full molt and therefore cannot
fly.
- What is the anticipated success of trapping?
Trapping success is really up to the behavior of the resident Canada
geese. Refuge staff will assess, on a daily basis, the behavior and
movement of birds and determine whether or not trapping will be
effective. Further, humane treatment of any captured birds requires
that all features of the operation must be in place (from equipment to
processor) prior to beginning a trapping effort. Refuge staff hopes
that the trapping will remove enough resident Canada geese so as to see
immediate relief of the croplands and marshlands currently experiencing
the heaviest over-grazing.
- Did the Service consider a regulated hunt to control
resident Canada geese?
Regulated hunting, one IWDM control method, has not been recommended
for use at this time. Hunting at other refuges and by the State has not
proven to be an effective population control measure. Hunting may be
considered in future years. A hunt program will require a separate
Environmental Assessment, Hunt Plan, and public notice in the Federal
Register.
At this point in time, hunting also presents safety problems and will
interfere with other visitor’s opportunities to view or observe
wildlife. This is due to the fact that since the majority of resident
geese are located in the public use areas (where the majority of
habitat damage is occurring) a safe hunt would necessitate closing of
the Wildlife Drive and place other severe constraints on the refuge’s
ability to offer visitors wildlife and environmental observational
opportunities simultaneous to a regulated hunt.
See also ENVIRONMENTAL ASSESSMENT for
the management of conflicts associated with non-migratory (resident)
Canada geese
