1.0 INTRODUCTION
Blackwater National Wildlife Refuge (NWR) is located in Dorchester County,
Maryland, about
12 miles south of Cambridge. It was officially established under
the authority of the Migratory
Bird Conservation Act on January 23, 1933 to provide habitat for migrating
and wintering birds.
The original size of the refuge was approximately 8,241 acres.
Since that time, additional lands
have been added to the refuge under the authorities of the Endangered
Species Act (ESA), North
American Wetlands Conservation Act (NAWCA), the Refuge Administration
Act (RAA), and the
Refuge Recreation Act (RRA) for the purposes of providing additional
wetland habitats for
migratory birds and for the bald eagle, the Delmarva fox squirrel,
and other endangered species.
The refuge, managed by the U.S. Fish and Wildlife Service (FWS) as
part of the National Wildlife
Refuge System, now totals approximately 24,000 acres of tidal marsh
and open water areas,
wooded wetlands, pine and mixed hardwood forests, and agricultural
lands. The mission of the
National Wildlife Refuge System is "to administer a national network
of lands and waters for the
conservation, management, and where appropriate, restoration of the
fish, wildlife and plant
resources and their habitats within the United States for the benefit
of present and future
generations of Americans" as stated in the National Wildlife Refuge
Improvement Act (October 9,
1997).
Management actions on national wildlife refuges are directed at achieving
the purposes for which
the refuge was officially established and the mission of the National
Wildlife Refuge System. The
enabling legislation defines the purposes, which guides the subsequent
development of specific
refuge objectives. The purposes for which Blackwater NWR was
established depend upon the
authorizing legislation under which the property was acquired.
Land for Blackwater NWR has
been acquired under the authority of five different legislative acts.
While each varies somewhat in
emphasis, the consistent theme is the protection and enhancement of
natural resources, in
particular to protect, enhance, and restore wetlands and other habitats
for the benefit of migratory
birds, endangered and threatened species, and other wildlife, as well
as providing for compatible
fish and wildlife-oriented recreation. Given these authorities,
the following primary resource
management objectives have been established for Blackwater NWR:
1. Provide resting and feeding areas for migratory birds, primarily wintering waterfowl;
2. Provide
protection and essential habitat for endangered species such as the bald
eagle,
Delmarva fox squirrel, and Arctic peregrine
falcon;
3. Provide
habitat for National Species of Special Emphasis, such as the black duck
and
wood duck;
4. Provide quality interpretive opportunities for refuge visitors; and
5. Provide
a site for conducting scientific research leading to the enhancement of
wildlife
and natural resource management.
1.1 PURPOSE OF THE ENVIRONMENTAL ASSESSMENT
FWS is authorized
and directed by Executive Order 13122 to protect native wildlife and
their habitats on NWRs from damage associated
with invasive and injurious species,
including damage related to migratory birds.
Wildlife damage
management, or control, is defined as the alleviation of damage or
other problems caused by or related to the
presence of wildlife. It is an integral
component of wildlife management (Leopold
1933, The Wildlife Society 1990, Berryman
1991). The Wildlife Services program
of the Department of Agriculture (USDA-APHIS-WS)
uses an Integrated Wildlife Damage Management
(IWDM) approach (sometimes referred
to as Integrated Pest Management or IPM) in
which a combination of methods may be
used or recommended to reduce wildlife damage.
FWS has adopted these methods
which include the alteration of cultural practices
as well as habitat and behavioral
modifications to prevent damage. The
control of wildlife damage may also require
that the offending animal(s) be removed or
that the population of the offending
species be reduced through lethal methods.
Blackwater NWR
proposes to conduct a wildlife damage control program on the
refuge using the IWDM approach to manage conflicts
associated with resident Canada
geese. This environmental assessment (EA)
documents the analysis of the potential
environmental effects of the proposed program.
This analysis relies mainly on existing
data contained in published documents including
the Animal Damage Control Final
Environmental Impact Statement (U.S. Dept.
Agri. 1994) and the Animal and Plant Health
Inspection Service, Wildlife Services' Environmental
Assessment for Management of
Conflicts Associated with Non-migratory (Resident)
Canada Geese, Migratory Canada
Geese, and Urban/Suburban Ducks in the Commonwealth
of Virginia (U.S. Dept. Agri. 1999).
Normally, according
to Animal and Plant Health Inspection Service (APHIS) procedures
implementing the National Environmental Policy
Act (NEPA), individual wildlife
management actions may be categorically excluded
from the requirements to prepare
an EA. FWS typically considers the normal
issuance of migratory bird permits to be a
Categorical Exclusion to NEPA. However, given
broader responsibility within the NWR
System, Blackwater NWR has decided in this
case to prepare this EA to facilitate
planning, enhance interagency coordination,
and streamline program management,
and to clearly communicate the analysis of
impacts.
1.2 NEED FOR THE ACTION
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.
Canada geese are classified as
migratory birds and are managed under the
Migratory Bird Treaty Act (MBTA). Resident
Canada geese are currently adversely affecting
the purpose(s) for which Blackwater
NWR was established.
Blackwater NWR
was established under the authority of the Migratory Bird
Conservation Act (16 U.S.C. 715 d) for the
purpose as "an inviolate
sanctuary for migratory birds." The
refuge's resident Canada goose population has
increased from an estimated 350 in 1989 to
more than 5,000 in 1998. Statewide, the
resident Canada goose population has increased
from 25,000 in 1989 to 90,000 in 1998.
(Maryland's population objective for resident
Canada geese is 30,000). The direct and
indirect results of this population explosion
are adversely affecting the primary
purpose for which the refuge was established.
These resident geese are destroying the
refuge's natural marsh vegetation that is
already stressed by sea level rise, salt water
intrusion, and overgrazing by nutria (an exotic
mammal introduced in the 1940's), and
are contributing to the loss of wetlands important
to the Chesapeake Bay ecosystem.
They are seriously affecting moist soil plant
production in the refuge's impoundment
system, and are also responsible for damaging
agricultural crops planted to provide
critical forage for migrating and wintering
waterfowl. 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.
For example, during a survey conducted by
the National Wildlife Health Research Center
(NWHRC), 16% of 37 resident Canada geese
studied from Blackwater NWR were DVE (duck
virus enteritis or duck plague) positive.
There is also increased concern regarding
transmission of diseases such as
cryptosporidiosis, giardiasis, and chlamydiosis.
Because of this potential problem, the
FWS (Northeast Region) is funding an investigation
by NWHRC in 1999 to evaluate
threats to human health posed by resident
Canada geese in Rhode Island, New Jersey,
and Virginia.
Resident gosling
production on the refuge in 1998 exceeded 2,000, and resulting
damage to refuge habitats was significant.
The refuge's 750 acres of croplands and 600
acres of moist soil impoundments were devastated
from excessive overgrazing during
the growing season despite the expenditure
of at least one full staff year of effort
and thousands of dollars for harassment/scare
devices. When these habitats are
destroyed and 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, and the refuge cannot achieve the
purpose for which it was established. The
refuge population of resident geese is also
expanding to private lands, and it is not
uncommon to see flocks of nonbreeding
geese flying almost anywhere south of Route
50 during the spring and early fall. These
nonbreeders join with breeders and their fledgling
young in the early fall to cause
extensive damage by overgrazing and polluting
private agricultural fields, alfalfa
and hay meadows, lawns, golf courses, and
other areas.
Therefore, the
U.S. Fish and Wildlife Service proposes to conduct a program on
Blackwater NWR in which an IWDM approach will
be employed to manage conflicts
associated with resident Canada geese.
1.3 RELATIONSHIP
TO OTHER ENVIRONMENTAL DOCUMENTS
AND OTHER ON-GOING FWS ACTIVITIES
The USDI, FWS
has completed, in cooperation with State wildlife agencies and APHIS-WS,
an
EA that could turn over the management authority
for resident Canada geese (from
March 11 through August 31) to State Agencies
via a depredation permit. This would greatly
simplify the permit process, but really does
not support a resident Canada goose
management program. The FWS justification
for this permit is... "These increasing
populations of locally-breeding geese are
resulting in increasing number of conflicts
with human activities, and concerns relating
to human health and safety are
increasing...". At this time, it does
not appear that a State Wildlife Agency will apply for
this permit in Region 5.
The Service
realizes that more management flexibility for Resident Population Canada
geese is necessary. Because of the unique
locations where large numbers of Canada geese
nest, feed and reside, the Service believes
that new and innovative approaches, and
strategies for dealing with bird/human conflicts
will be needed. In order to address
these issues, the Service has recently begun
the initial groundwork, with the full
assistance of the Flyway Councils and
APHIS-WS, to develop a long-term strategy to
integrate our management of these birds into
a more comprehensive Flyway Management
Plan system. The Service believes that
this approach should provide States with
more
management flexibility and authority to deal
with Resident Population Canada geese
within their state, while increasing commitment
to establish population goals and
objectives, management planning, and population
monitoring. However, in order to
properly examine alternative strategies for
control and management of resident Canada
geese populations, the Service believes the
preparation of an EIS will be necessary.
Moreover, the
finalized FWS permit procedures and the Blackwater NWR program have
similar justifications and proposed actions
(e.g., use of applicable non-lethal methods,
time period geese may be taken, donating of
geese to charity, methods of take, etc.). The
Atlantic Flyway Council (AFC) is developing
a resident Canada goose management plan to
support the future EIS. In addition,
the AFC has approved an overall population objective
for resident Canada geese and is stepping
this population objective down to appropriate
state objectives.
Other on-going
FWS activities include establishment of special hunting seasons in
September and January/February to address
control of the growing population of
resident geese. Depredation permits
are routinely issued to shoot limited numbers of
Canada geese to improve non-lethal harassment
of these birds from depredation sites, and
depredation permits have been issued in Delaware,
New York, Maryland, and Virginia over
the past 5 years to trap and kill large numbers
of Canada geese to reduce a local problem
population.
1.4 RESIDENT
CANADA GOOSE BIOLOGY AND STATUS
Present-day populations
of resident (non-migratory) Canada geese on Blackwater NWR
originated from birds that were released or
escaped from private waterfowl collections
or hunting clubs 40-50 years ago, and from
birds that were moved to the refuge from
other areas. These non-migratory stocks
of geese probably include a mix of several
different subspecies including the giant (Branta
canadensis maxima),
western (B.c. moffitti), and interior (B.c.
interior) races. The refuge
resident goose population has grown from only
about 350 birds in 1989 to more than 5,000
in 1998, and increased by almost 70% in just
the last breeding season. This increase may be
the result of the exploitation of man-made
food resources, i.e., clovers, corn, winter
wheat, buckwheat, and other agricultural crops
planted on the refuge resulting in
improved nutritional health and thus better
reproductive success and gosling survival;
few predators; and almost complete protection
from harvest by hunting except when
birds fly to private lands. The resident
Canada goose's feeding and breeding behavior,
habitat preference, and adaptability to man-made
environments create situations in
which Canada geese and humans conflict. Resident
Canada geese feed on clover, grasses,
and cereal grains, exactly the types of crops
that migratory Canada geese need to survive
the winter. Resident Canada geese also
favor short, manicured grass, particularly near
a water source, for loafing and feeding.
Refuge dikes, important for managing water
levels for migratory waterfowl, shorebirds,
and other marsh and water birds, provide
just such feeding and loafing areas which
resident birds quickly denuded of vegetation
causing erosion and dike failure.
Another indicator
of the increasing problems with resident Canada geese is the number
of complaints received by USDA's Wildlife
Services Office. In 1993, the Annapolis office
received no complaints from Dorchester County
residents. In 1994, 1995, 1996, 1997, and 1998,
complaints increased to 3, 5, 4, 4, and 6,
respectively. While the number of complaints is
relatively low, it is interesting to note
that while only $300 in economic damage was
noted from 1993 through 1997, $34,000 in damages
to private agricultural crops was noted
in 1998. (Damages sustained by the refuge
during these years were not included in these
statistics.)
Resident Canada
geese nest from March through June. Eggs take approximately 30 days
to
hatch. Parent geese are very protective
and aggressive in defense of young and nest. This
aggressive behavior can potentially lead to
attacks on human visitors, particularly
visitors along the refuge's wildlife drive
where geese sometimes nest.
The refuge is
not open to the special Maryland September hunting season for resident
Canada geese since waterfowl hunting would
interfere with other management
objectives and refuge purposes. However,
even if the refuge were open to public waterfowl
hunting, control of resident Canada geese
would be extremely minimal based on the
reports of harvest statistics obtained from
E.B. Forsythe NWR in New Jersey and Tudor
Farms, Inc., a 6,000-acre private hunting
preserve adjoining the refuge. At E.B. Forsythe NWR,
762 hunters, hunting 3,866 hours during three
consecutive state seasons, only killed 413
geese from the refuge's impoundment system.
Despite considerable hunting pressure at
Tudor Farms, Inc., very few geese were taken
during the 10 day State season, and the
landowner has been forced to acquire a depredation
permit from the FWS.
1.5 WILDLIFE ACCEPTANCE CAPACITY
Human dimensions
of wildlife management include identifying how people are affected
by problems or conflicts between them and
wildlife, attempting to understand people's
reactions, and incorporating this information
into policy and management decision
processes and programs (Decker and Chase 1997).
Wildlife acceptance
capacity is the limit of human tolerance for wildlife or the maximum
number of a given species that can coexist
compatibly with local human populations.
Wildlife acceptance capacity is also known
as the cultural carrying capacity. These terms
are important because they define the sensitivity
of a local community to a specific
wildlife species. For any given damage
situation, there will be varying thresholds by those
directly and indirectly affected by the damage.
This threshold of damage is a primary
limiting factor in determining the wildlife
acceptance capacity.
Biological carrying
capacity is the land or habitat's limit for supporting healthy
populations of wildlife without degradation
to the animal's health or its environment
over an extended period of time (Decker and
Prudy 1988).
Based on observations
by trained wildlife biologists and cropland managers at
Blackwater NWR who have been monitoring the
effects of resident Canada geese for the
past 10 years, it appears that the affected
environment is being significantly impacted
when the resident Canada goose population
exceeds 300 to 350 (1989 population levels). The
wildlife acceptance capacity by the public
is much higher than the biological carrying
capacity, because the public is not affected
directly and visitors to the refuge are
particularly pleased to see and observe goslings
and adult Canada geese year round in
large numbers. This is exactly the opposite
of urban situations where the acceptance
capacity is 20-30 resident Canada geese in
subdivisions and water front communities, or on
golf courses where the acceptance capacity
is 25-30 birds (Conover and Chasko 1985). The
acceptance capacity, however, for adjacent
private farmers is probably more consistent
with the urban situations. When flocks of
20 to 30 resident geese are observed to be
feeding in agricultural croplands more than
a couple of consecutive days, farmers will
implement some type of control. This response
is consistent with other situations in
which the wildlife acceptance capacity is
met or exceeded; people begin to implement
population control methods, including capture
and euthanasia, to alleviate property
damage and human health or safety threats
related to accumulation of fecal droppings.
In past years when birds were relocated to
areas that didn't have resident Canada geese,
residents in the receiving area immediately
phoned the refuge to complain about damage
to their lawns and gardens and the abundance
of fecal droppings on sidewalks, lawns,
and vehicles.
2.0 SCOPING/PUBLIC PARTICIPATION
2.1 INTERNAL
SOLICITATION FOR INPUT, INFORMATION, AND
ISSUES
2.1.1 Internal/External Scoping: Internal solicitation for input,
information,
and issues was conducted by biologists and managers on the refuge
who first analyzed
the data on resident Canada geese that had been collected
since 1989,
including the effectiveness of these actions. Staff also consulted
with
biologists,
NEPA Coordinators, flyway representatives, and senior staff in the
Washington and
Regional Offices (Northeast Region), USDA-APHIS-Wildlife Service's
staff in Maryland
and Virginia, and staff in the Wildlife and Heritage Division-
MDDNR. Informally,
refuge staff also discussed the resident Canada goose problem
with several
adjacent landowners and farmers, particularly those experiencing
similar damage
problems.
From April 14, 1998 until May 19, 1998, the refuge conducted 17 public
forums at
locations in
Talbot, Dorchester, Caroline, Wicomico, and Somerset Counties,
Maryland, and
sent issue workbooks to 3,800 people as part of the refuge's
Comprehensive
Conservation Planning effort. Injurious and invasive species
management,
and specifically resident Canada goose management, was a major
topic during
these scoping meetings. The problems with resident Canada geese
were addressed
with the public, and ideas, including the alternatives listed
herein, were
discussed.
2.1.2 Issues: Several issues were identified: Aesthetics, animal
welfare, effects
on human health
and safety, biological impacts of management actions (i.e.,
impacts on resident
Canada geese and migrant/wintering waterfowl, endangered
species, non-target
species, agricultural losses, natural resources, etc.), effects on
economics, cost
to implement control programs, effects on refuge purposes and
natural resources,
effects on the physical environment, and effects on
recreational
hunting opportunities.
Wildlife is generally regarded as providing economic, recreational, and
aesthetic
benefits (Decker
and Goff 1987), and the mere knowledge that wildlife exists is a
positive benefit
to many people. Aesthetics is the philosophy dealing with the
nature of beauty,
or the appreciation of beauty. Aesthetics is truly subjective in
nature; dependent
on what an observer regards as beautiful. Wildlife populations
provide a range
of social and economic benefits (Decker and Goff 1987). These
include direct
benefits related to consumptive and non-consumptive use (e.g.,
wildlife-related
recreation, observation, harvest), indirect benefits derived from
vicarious wildlife
related experiences, and the personal enjoyment of knowing
wildlife exists
and contributes to the stability of natural ecosystems. Positive
values of wildlife
would also include having enough wildlife to view, but also to
enjoy the aesthetics
of the local environment without excessive animal excrement
or loss of habitat
that adversely affects other wildlife. The same wildlife that is
enjoyed by many
can also create conflicts with a number of land uses and human
health and safety.
Economic losses to agriculture and damage to property are
widely recognized
as problems resulting from overpopulations of resident
Canada geese.
Public reaction is variable and mixed because there are numerous
philosophical,
aesthetic, and personal attitudes values, and opinions about the
best ways to
manage conflicts between humans and wildlife. Some people have the
view that resident
Canada geese should be captured and relocated to a rural area
to alleviate
damage or threats to refuge habitats. Others feel that resident geese
should be managed
for their recreational enjoyment (hunting, wildlife
observation)
and should be allowed to exist unharmed and unmanaged,
particularly
when migrant populations are low and hunting has been suspended.
Many people
don't really understand the difference between resident Canada
geese and migrant
Canada geese; a goose, is a goose, is a goose. And still others
believe that
resident Canada goose numbers should be significantly reduced by
agency control
programs.
The issues of animal welfare, the killing of geese, and humaneness were
identified
and discussed.
Views vary greatly about killing of resident Canada geese; from
being totally
opposed, to believing that population management is an important
part of wildlife
management. The issue of humaneness, as it relates to the killing
or capturing
of wildlife, was also an issue that can have different interpretations
by different
people. Humaneness is a person's perception of the impact of an action.
Animal welfare
groups and animal rights organizations have expressed concern
about inhumane
methods that expose the animal to unnecessary pain and
suffering.
Effects on human health and safety were identified as an issue because
of the
public's concerns
about excessive accumulations of resident Canada goose fecal
materials.
Although not a problem as yet for the refuge, except on the refuge
wildlife auto
drive and bicycle/pedestrian route, where geese often roost and
literally leave
the roadway covered in excrement, most concern about this issue
has been expressed
from geese being relocated to other areas and then taking up
residence on
lawns and sidewalks of private residents. The general public's
perception is
that excrement is the perfect medium for transmission of disease.
However, there
is little evidence to support this concern, at least at present.
Biological impacts of the proposed management actions were also identified
as
issues, including
impacts on the resident goose population itself and impacts to
non-target species.
Impacts on migratory Canada geese and other waterfowl,
agricultural
losses, effects to natural resources such as affected water quality,
and effects
on the physical environment were identified.
3.0 ALTERNATIVES, INCLUDING THE PROPOSED ACTION
3.1 NO ACTION
For the purposes
of this EA, the No Action Alternative is a "no management" approach.
Under this alternative, there would be no
control program actions at Blackwater NWR
directed at management of damage associated
with resident Canada geese. The resident
Canada goose population would continue to
reproduce and expand unchecked.
3.2 NON-LETHAL
PROGRAM ONLY (Essentially The Current
Program)
Under this alternative,
only non-lethal management approaches will be used. Approved,
non-lethal methods potentially available to
Blackwater NWR for management of
resident Canada geese include habitat alteration/creation;
physical exclusion through
wire grids, perimeter fencing, and floating
ball blankets; or frightening and harassment
methods such as pyrotechnics, propane cannons,
reflective tape, eye-spot balloons, flags,
and chase dogs; and chemical repellents.
Relocation and contraception are not approved
methods of non-lethal control in Maryland.
From 1989 through
1998, the current resident Canada goose control program has focused
entirely on non-lethal methods, including
habitat alteration/creation and the
extensive use of frightening and harassment
methods (pyrotechnics, propane cannons,
reflective tape, eye-spot balloons, and flags).
Chemical repellents have also been
investigated, but not used.
Habitat alteration/creation
has been accomplished through the planting and/or
mowing of winter wheat and clover to "lure"
resident geese away from agricultural crops
and moist soil impoundments. This practice
of "luring" resident geese was largely
ineffective. The lure crops reduced
damage for only very short time periods, and once
these acres were consumed, geese went immediately
back to destroying more highly prized
habitats. It is suspected that this
practice also resulted in contributing to the health
and vigor of the resident geese, increasing
their survival and reproductive capabilities.
Physical exclusion
methods are not feasible to use on 14,000 acres (See Section 5.2). These
methods, such as wire grids, perimeter fencing,
and floating ball blankets, are
recommended for small areas only (two acres
or less) because of the installation and
maintenance costs. They have not been
part of the current program, nor are they being
recommended as part of this alternative.
Frightening and
harassment methods have been the most frequently used practices for
eliminating conflicts with resident Canada
geese, and would be recommended for
continued use in this alternative. A
wide variety of auditory and visual stimuli have been
extensively used in the current program. Pyrotechnics,
propane cannons, flags, reflective
tape, eye-spot balloons, and chasing have
all been used, and will continue to be part of
this alternative. Pyrotechnics (screamer
shells, bird bombs, and 12-gauge cracker shells)
have been used repeatedly to repel resident
geese, but as with most of these methods, the
resident geese soon became habituated and
would only leave to return a short time later
and resume their damaging activities.
More often than not, unless reinforced by someone
physically chasing the birds, the resident
geese would simply ignore these exploding and
noise-making devices entirely. Pyrotechnics
are extremely dangerous, require staff time
to deploy, and have started fires and caused
serious accidents on Blackwater Refuge
during the nine years they have been used.
They are also extremely disturbing to other
wildlife and to the public.
Also very annoying
to the public are propane cannons which operate on gas and are
designed to produce loud explosions at controllable,
several minute intervals, 24 hours
a day. The cannons are used currently,
and would continue to be used in this alternative.
They are automatically set and do not require
staff to be physically present. The repeated,
loud explosions can be heard for miles, and
many refuge neighbors have complained about
the cannons being totally unacceptable, particularly
at night. Additionally, the resident
geese have become increasingly habituated
to the noise.
Flags are currently
being used, but are the least effective of the frightening/harassment
methods. Reflective tape, red on one
side and silver on the other, is also currently being
used. The tape is strung at close intervals
over the fields and impoundments (20 to 30 feet
apart, 2 to 3 feet above the vegetation).
The tape blows in the wind, and for short times
does cause resident geese to avoid the specific
area. But like many other non-lethal
methods, geese soon habituate to the tape.
The tape also is very costly, and is difficult and
labor intensive to maintain. Deer frequently
get caught in the tape at nighttime, and
tear down two days work in a matter of hours.
The tape then blows onto the highway,
wildlife drive, and/or into the river and
marshes creating additional work for litter
removal.
Eye-spot balloons,
balloons with holographic eyes that move up and down as balloons bob
on spring loaded posts, accompany the reflective
tape. Depending on the size of the area,
as many as 20 to 30 brightly colored balloons,
generally yellow or orange, have been
positioned throughout each affected field
or impoundment. The balloons, like the tape,
are very costly and labor intensive to install
and maintain. They are also effective only
for a week or two before resident geese habituate
to their presence. Aesthetically, the
balloons, as well as the tape and flags, greatly
detract from the visitor's "wildland"
experience.
Chase dogs, while
not used in the current program, are a potential nonlethal method of
control. However, they have been found
to have limited effectiveness, particularly in
areas such as Blackwater where resident geese
can seek refuge on adjacent water areas.
The cost of trained chase dogs that would
not affect the visiting public or other
wildlife (e.g., deer or Delmarva fox squirrels)
is very high (see 3.4.1).
Chemical repellents
have been investigated for current use, but have not been used
because of cost. Methyl anthranilate,
a grape flavored food additive approved by FDA, is
sometimes effective at repelling resident
Canada geese from grazing on turf for four
days, but is rendered ineffective when rained
on or mowed. This chemical costs
approximately $137.00 per acre to use.
The need for repeated applications, cost, number of
acres to be treated, and relative ineffectiveness
make use of this repellent questionable.
Relocation, the
capture of resident geese and their translocation to other areas of the
refuge, has been used repeatedly over the
last four years. Over 1,000 resident geese have been
live captured annually in each of the past
two years and translocated to other parts of
the refuge. When the juvenile resident
geese are still flightless and the adults are in
molt, generally from mid-June to mid-July,
geese are herded into large funnel traps (drive-
traps), individually placed in crates, transported
to other areas on the refuge, and
released back into the wild. During
the past, Maryland DNR only authorized relocation
of captured resident geese to other parts
of the refuge. In the future, Maryland DNR will
not allow resident geese to be relocated and
released anywhere once they have been
captured.
3.3 LETHAL
PROGRAM ONLY
Under this alternative,
only lethal direct control will be used. Approved lethal methods
potentially available to Blackwater NWR for
population reduction of resident Canada
geese include hunting, nest/egg destruction,
and live capture with humane euthanasia
by certified processors only (see the following
proposed action for further description
of authorized lethal control methods). Chemical
toxicants are not an approved method
of lethal control.
3.4 INTEGRATED
WILDLIFE DAMAGE MANAGEMENT PROGRAM
(PROPOSED ACTION)
Under this alternative,
a combination of nonlethal and lethal management approaches
will be used. Consistent with APHIS - WS and
Maryland DNR's resident Canada goose
management policy, nonlethal methods will
be given first consideration in the
formulation of each damage management strategy,
and will be implemented when
practical and effective before implementing
lethal methods.
At Blackwater,
the IWDM approach would consist of implementing one or a combination
of the following actions: (1) Resource
management, defined as altering habitat; (2) limited
physical exclusion (fencing); and/or (3) wildlife
management (frightening methods and
population reduction). Within each of
the three actions, there are a number of specific
methods or tactics that will be used singularly
or collectively. Within any given year, the
methods and/or sequence of methods will be
tailored to meet the overall objective of
reducing (subsequently maintaining) the refuge
resident Canada goose population at the
1989 level. At no time will the collective
use of methods result in actually taking more
than 3.5% of the statewide resident goose
population in any given year. In determining the
sequence or combination of methods to be applied,
preference would be given to practical
and effective nonlethal methods. However,
nonlethal methods will not always be applied
as a first response to damage problems.
A logical annual
sequence that is in accordance with the new Maryland DNR policy
would include the following actions: Egg shaking/oiling/puncturing
would be
conducted in late March through April of the
current year. Frightening/harassment
practices and methods would be applied in
May and early June consistent with current
practices described in the nonlethal alternative,
and supplemented by limited shooting
of adult birds to reinforce these harassment
techniques. Where feasible, limited physical
exclusion (fencing) will also be employed
during this time period. Live capturing of
preflighted juvenile and molting resident
Canada geese will be conducted in accordance
with current "drive-trapping" practices beginning
on or around mid-June thru mid-July
(dependent upon the exact time of the molt,
weather conditions, responsiveness of the
resident geese, and availability of staff).
Geese will only be live captured on overcast days
and early in the mornings to keep geese from
becoming overly stressed due to warm
temperatures. If necessary, additional
resident geese will be live captured in late July
until the August 21 deadline with rocket nets
while they feed on baited areas. Once live
captured, the juvenile and adult resident
geese will be placed in properly ventilated
transportation crates, and transported to
a certified processor. The processor will
euthanize the geese in accordance with AVMA
(American Veterinary Medical Association)
methods and Maryland policies. The processed
meat will be donated to a charitable
organization. In accordance with Maryland's
policy, all captured birds must be donated
for use as food; a state or USDA licensed
meat processor must have agreed in advance of
capturing the geese to process the birds according
to guidelines developed by the
Maryland DNR, Maryland Department of Agriculture,
and the Maryland Department of
Health and Mental Hygiene; and a charitable
organization or agency must have agreed
in advance to accept the meat.
This general
sequence will be followed each management year until the 1989 objective
level
of 350 resident Canada geese is reached.
However, the sequence of methods will likely
change annually depending on the population
level, the location and amount of habitat
being impacted, overall responsiveness of
the resident geese once lethal control is
implemented, and effectiveness of these efforts,
etc. Certainly, as we progress towards
achieving the population objective, there
will be less need for lethal control. The IDWM
methods used will be evaluated annually to
determine effectiveness in relationship to
achieving the program's objectives.
In implementing
IWDM, the primary social issues relative to managing wildlife damage will
be considered. These are humaneness,
effectiveness, and ecological soundness.
Effectiveness will be determined by how quickly,
economically, and completely the
methods resolve the problem. Effective
damage resolution is often best attained through
the integration of several methods, either
simultaneously or sequentially. Methods or
management strategies will be evaluated considering
maximum damage resolution with
minimal negative environmental impacts.
The proposed
action will also incorporate education as an important element of the
program's activities. In addition to
dissemination of recommendations and information
to individuals and other organizations sustaining
damage, environmental education
lectures to school groups and displays at
the visitor center will focus on problems with
resident Canada geese and other invasive and
injurious species, their effects on native
wildlife and their habitats, and the socio-economic
impacts. The refuge will also provide
technical assistance based on its experiences
to other refuges, wildlife management areas,
and adjacent landowners experiencing similar
problems with resident Canada geese. The
refuge will work closely with APHIS-WS and
MDDNR personnel regarding distribution of
literature and interagency coordination of
educational activities. The refuge biologist
will also monitor the program annually; collect
information on types and effectiveness
of various control techniques used; number
and age class of birds removed; etc., and
publish the results to better refine control
measures in relation to humaneness,
effectiveness, and ecological soundness. The
biological information will also be used to
determine a particular year's sequence and/or
types of control measures.
3.4.1 IWDM
Techniques Considered But Dismissed From
Proposed Action:
Several techniques,
normally associated with IWDM, were considered, but will not be used
in the Proposed Action, at least at this time.
These include use of wire grids, floating ball
blankets, use of guard animals, use of distress
calls, relocation, creation of alternative
habitats, public hunting, and chemical toxicants.
Evaluations will be performed at the
end of each year to determine the effectiveness
of control methods in relationship to
the program's objectives and in relationship
to other refuge activities and needs.
Conditions may change which might make one
or more of these methods applicable in the
future.
Wire grids and
floating ball blankets are only used on small waterbodies (approx. 2 acres
or less) to keep resident geese from using
these areas. They are only effective on small
ponds, and costs for installation are $1,000
and $131,000 per surface acre, respectively. It
would currently be inconceivable to use these
techniques on 12,000 acres of marshland,
750 acres of cropland, and 600 acres of moist
soil impoundments, but these methods may
be applicable as the population reaches the
1989 level.
Guard animals
may be used to frighten resident Canada geese from areas where damage is
occurring. Dogs can have limited effectiveness
at harassing geese, but are normally used
on small areas without water where harassed
geese must go elsewhere to seek refuge.
Border collies have been trained to accomplish
this work. A well trained border collie
that will harass geese and not effect other
wildlife (e.g. Delmarva fox squirrels, etc.) costs
approximately $2,000 to $4,000 per dog.
Several dogs would likely be necessary to be even
somewhat effective. Therefore, because
of their limited effectiveness on such a large area
as the refuge and the cost, this method was
dismissed from current use.
Distress calls
have been found ineffective at causing resident geese to abandon a pond
(Aguilera et al. 1991). Distress calls
for Canada geese are not commercially available. The Av-
alarm, a commercially available electronic
sound generating device, is ineffective at
repelling migrant Canada geese (Heinrich and
Craven 1990).
Relocation of
wildlife must be approved by the MDDNR for it to be a legal alternative.
MDDNR and most, if not all, other states oppose
relocation of resident Canada geese since
the potential for damage is moved to the new
location. This has clearly been the case in
past at Blackwater when geese were relocated
to other remote parts of the refuge only
to immediately move to the lawns of private
citizens destroying gardens and defecating
on everything in sight. Relocated waterfowl
have also caused epizootic and avian disease
outbreaks in some areas. Furthermore,
relocation attempts are extremely temporary, and
unsuccessful. At Blackwater, molted
(nonflying) geese and goslings relocated as far away
as Martin National Wildlife Refuge (approx.
30 miles away) swam back to Blackwater within
two weeks, even before they could fly.
This has been the case for most of the 2,000 birds
that have been captured and relocated to other
parts of the refuge during the past two
years as verified by neckbanded geese and
recovery of leg bands. However, if policies
change, trapping and relocation may be an
acceptable control method.
Creation of alternative
habitat would provide geese a place to live, but would create
additional problems since these created habitats
would only be of value until the
population moved or outgrew the area.
Created habitats would also probably serve as
attractants, bringing more resident Canada
geese to the refuge.
Contraception
is not an available means of control since no contraceptive drugs are
registered with the FDA for use in limiting
reproduction of Canada geese or other
waterfowl. Furthermore, contraception is not
an approved method by MDDNR. Canada
geese have been successfully vasectomized
to reduce recruitment into future populations,
however this may be effective only if the
male remains mated and it only affects
reproduction from that male's female mate.
The ability to identify breeding pairs for
isolation and to capture a male goose for
vasectomization becomes increasingly difficult
as the number of geese increase (Converse
and Kennelly 1994).
Hunting may reduce
resident Canada goose populations, but would currently conflict
with other refuge objectives. (See Sections
1.4 and 5.3.1 for further discussion on hunting.)
Hunting may be considered as an IWDM method
in combination with other methods if
future evaluations justify its use without
conflicting with other refuge objectives. If
hunting is recommended in the future, a separate
EA, Hunt Plan, and Federal Register
notice must be completed before hunting is
authorized.
There are no
toxic chemicals currently registered with the EPA for use in managing
resident Canada geese.
4.0 AFFECTED ENVIRONMENT
The environment affected by the proposed action would be primarily the
vegetation and wildlife
resources; however some effect could occur on the physical resources
of soils, hydrology, and
air quality. Cultural, aesthetic, and socio-economic resources
also could be impacted.
Discussion of the affected environment and impacts will be limited
to these resources, which
have been identified as the most likely to be affected by the proposed
action and its alternatives.
A. Physical Resources
In this section, information is presented regarding the physical resources
that could be
affected by or affect the control of resident Canada geese on Blackwater
NWR. Specifically, this
section will cover location, geology and soils, hydrology, and air
quality.
1. Location
Blackwater NWR is located south of the Choptank River on the eastern
side of the Chesapeake Bay,
Maryland’s Eastern Shore. Both areas are part of the Chesapeake
Bay Ecosystem, the largest estuary
in the United States. Isolated islands or small clumps
of firm ground dot the vast marsh
landscape. Surrounded by shallow sounds, marsh islands, and adjacent
waters are the Bay’s most
productive estuarine areas. They produce the aquatic and
emergent plant communities, which
in turn provide optimum habitat for large concentrations of waterfowl,
and nursery areas for
small fish and crabs. Blackwater NWR is located in Dorchester
County, Maryland, approximately
12 miles south of Cambridge. The refuge complex is comprised
of three refuges: Blackwater NWR,
which is the administrative center; Susquehanna NWR, located on Edmondson’s
Island at the
mouth of the Susquehanna River in Hartford County, Maryland; and Martin
NWR, located on
Smith Island in Somerset County, Maryland approximately 15 miles offshore
from Crisfield.
Blackwater NWR is currently comprised of approximately 24,000 acres
of tidal marsh and open
water areas, wooded wetlands, loblolly pine and mixed hardwood forests,
freshwater
impoundments, and agricultural lands.
2. Geology and Soils
Blackwater NWR lies within the Mid-Atlantic Coastal Plain. The
topography is flat with elevations
ranging from 0 to 8 feet above mean sea level. Soils of the tidal
marshes and other low-lying areas
are either of the Bestpitch, Transquaking, Honga, or Sunken mucky silt
loam series. The Bestpitch,
Transquaking, and Honga soils are characterized by very deep organic
deposits over clayey
estuarine sediments, except Honga which overlies fluvio-marine sediments.
All are poorly
drained, with more rapid permeability in the organic deposits and slower
permeability in the
underlying deposits. Bestpitch and Transquaking soils are typical
of the estuarine tidal marshes,
while Honga soils are more typical of the submerged-upland tidal marshes.
The Sunken mucky silt
loam series, typical of lowland flats evolving into tidal marshes,
are also very deep, slowly
permeable and poorly drained, but are a mucky silt loam rather than
organic deposits over
fluvio-marine sediments. All four of these soil series are typical
along tidally-influenced rivers,
bays, and drainage ways. These soils generally have a 0 to 1
percent slope (USDA 1997). Pendleton and
Stevenson (1983) documented that marsh sediments averaged 58 percent
organic matter.
Upland soils are typically silt loams of the Elkton, Matapeake, Mattapex,
and Othello series. These
soils formed in silty deposits overlying sandy fluvio-marine sediments.
All are deep soils and are
moderately slowly, to slowly, permeable. The Matapeake and Mattapex
soils are well drained, while
the Othello and Elkton soils are poorly drained. These soils
are typical of the lowland flats,
with Elkton also occurring in depressions and swales and Matapeake
occurring on side slopes.
Othello soils are often in association with the Kentuck soils, which
are also very deep, slowly
permeable, and very poorly drained. The Kentuck soils also formed
in silty deposits overlying
sandy fluvio-marine sediments and are typical of lowlands, depressions,
and ancient floodplains.
These soils generally have a 0 to 2 percent slope (USDA 1997).
Marsh deposits on Blackwater NWR began about 3,800 years ago.
Many deposits are almost four
meters thick in the oldest areas of the marsh, but average deposits
are between two and three
meters thick. Most of the material is loose, organic muck.
The Blackwater and Little Blackwater
Rivers are the major sources of inorganic sediments for most of the
marshes on the refuge, with
occasional storm deposition from Fishing Bay being important for marshes
in the southeastern
part of the refuge. The emergent marsh is noticeably being replaced
by open water through
erosion, subsidence, sea level rise, increasing salinities, and eat-outs
from muskrats, nutria, and
geese. In the last 100 years, effective sea-level rise (land
subsidence added to sea level rise) has been
12 inches in the Chesapeake Bay area (Leatherman et al. 1995).
3. Hydrology
The Coastal Plain is underlain by unconsolidated sediments, which includes
all of the estuarine
wetlands. The area derives its ground-water recharge mainly through
infiltration of
precipitation. Discharge occurs through seepage to streams, estuaries,
and the ocean. Coastal
wetlands are in these discharge zones. These wetlands have complex
hydrology, of which
streamflow, ground-water flow, and tidal flow all play a part.
Forested wetlands occur along
the stream channels, and are sustained by local and regional ground-water
flow and flooding
during storm events. The poorly drained interior of the Delmarva
Peninsula has a system of
depressional palustrine wetlands, narrow bands of palustrine wetlands
along rivers and ditches
that drain from inland to the coasts. Extensive wetlands occur
along the coasts and inland
bays. In Blackwater NWR, brackish marshes grade into tidal freshwater
marshes (Hayes 1996).
Surface water on the refuge is derived from local precipitation.
Blackwater NWR has a relatively
large and efficient watershed, and receives substantial runoff from
Green Brier, Kentuck, Gum,
and Moneystump Swamps and from the tidally influenced Blackwater and
Little Blackwater Rivers,
which empty into Chesapeake Bay. Water samples from the Blackwater
River show that salinities
in the river range from 0 ppt to 19 ppt depending upon time of year
and tide, and most dissolved
oxygen levels fall within the range of 60 to 90 percent. Storm
tides associated with hurricanes
or northeast winter storms can cause extreme flooding of refuge wetland
areas, inundating
areas with saltwater, which results in salt-saturated soils and tree
mortality.
4. Air Quality
Dorchester County is classified as a Class II area under the Clean Air
Act, with air quality that is
generally good. Dorchester County is in attainment for all criteria
pollutants, which means
that it meets the National Ambient Air Quality Standards for emissions.
Visibility in the county
is good, generally averaging three to five miles. Facilities
within the county that could be
sensitive to smoke include Dorchester General Hospital, 9 miles from
the refuge; City of
Cambridge, 8 miles; Dorchester Airport, 8 miles; and Eastern Shore
Hospital Center, 8.5 miles. All of
these facilities are north of the refuge.
B. Biological Resources
Both vegetation and wildlife resources would be affected by actions
to manage the resident
Canada goose population.
1. Vegetation
Blackwater NWR consists of approximately 13,320 acres of tidal marshes
and open water areas, and
approximately 9,214 acres of woodlands. Approximately 750 acres
of the refuge are managed
agricultural units. Crops are planted annually to provide winter
food for migrating waterfowl.
Corn, clover, millet, milo, buckwheat, and winter wheat are the main
agricultural crops. Thirty
freshwater impoundments, totalling approximately 600 acres, have been
constructed since the
1940s, and these "moist soil management units" are managed intensively
for migratory birds.
Approximately 135 acres are refuge administrative lands, consisting
of roads, building, and
storage areas.
Blackwater NWR marshes, typical of Maryland’s Eastern Shore, are tidal,
brackish, estuarine
marshes. Because these brackish marshes form a wide transition
zone between the more seaward
marshes to the inland marshes, they generally have a high diversity
of plant species. Dominant
plant species include extensive areas of black needlerush intermixed
with saltmarsh hay,
saltgrass, Olney three-square bulrush, and smooth cordgrass (Tiner
and Burke 1995). At Blackwater
NWR, these marshes have been managed through burning for years, resulting
in the sub-climax
species, Olney three-square bulrush being the dominant marsh vegetation,
occurring in almost
monospecific stands (Pendleton and Stevenson 1983). However,
saltmarsh hay, smooth cordgrass,
saltgrass, and black needlerush are commonly interspersed among stands
of Olney three-square
bulrush. Several small pine islands are also distributed throughout
the marsh. When refuge
populations of wintering Canada geese reached almost 100,000 in the
late 1960's and early 1970's,
geese caused extensive damage to these fragile marshes creating eat-outs
that later enlarged and
combined to result in marsh loss to open water.
Portions of Blackwater NWR support one of the best examples of a complex
of tidal saltwater
wetlands, tidal freshwater wetlands, non-tidal wetlands, upland islands,
and Delmarva Bays in
Maryland. These wetland communities incorporate ten different
major tidal types and
approximately fifteen types of non-tidal wetlands. Both
estuarine and palustrine wetlands are
well represented. Within the palustrine wetlands, palustrine
forested, palustrine scrub-shrub,
palustrine emergent, and open water are the major types. The
federally endangered swamp pink
is believed to occur in bog-like habitats. Within the estuarine
wetlands, estuarine emergent,
intertidal forested, estuarine scrub-shrub, and aquatic bed are represented.
The whole gamut of
hydraulic regimes, ranging from seasonally saturated soils to permanently
flooded areas, can
be found in the palustrine wetlands, and the estuarine wetland regimes,
ranging from tidal to
irregularly flooded, are equally well defined. Tidal wetland
communities within these parcels
include salt marsh cordgrass, saltmeadow, saltbush, black needlerush,
freshwater mixed, arrow
arum-pickerel weed, cattail, narrowleaf cattail, yellow pond lily,
and tidal mudflat, which make
this complex extremely diverse.
Four forest cover types were delineated on the refuge by Whiteman and
Onken (1994). These are
loblolly pine, in which loblolly pine comprises at least 80 percent
of the basal area of the stand;
loblolly pine-oak, in which loblolly pine comprises 20-79 percent and
oak species account for 20
percent or more of the basal area; loblolly pine-mixed hardwood, in
which loblolly pine
comprises 20-79 percent and hardwoods other than oak comprise at least
20 percent of the basal
area of the stand; and mixed hardwoods, in which various hardwood species
account for at least
80 percent of the stand. The most dominant tree species on the
refuge is loblolly pine. The
common hardwoods include sweet gum, swamp chestnut oak, willow oak,
and white oak. In
addition to these four forest types, Whiteman and Onken (1994) also
delineated areas of blanket
tree mortality generally associated with flooding and saltwater intrusion,
with standing dead
trees ranging from 50 to 90 percent.
The upland agricultural and forested areas of the refuge provide additional
species diversity.
Being dominated by non-wetland species and providing transition zones
that usually are higher
in diversity, they provide excellent pine tree nesting and perching
sites for many of the more
than 160 bald eagles and 10 golden eagles that winter on the refuge.
The hardwoods, as well as
the pines, also provide excellent habitat for the Delmarva fox squirrel,
and numerous other
species.
2. Wildlife
Blackwater NWR provides habitat for a rich diversity of wildlife.
Over 257 species of birds, 30 species
of mammals and 40 species of reptiles and amphibians occur on the refuge
for at least part of the
year. An additional 25 species of birds have occasionally been
sighted on the refuge and an
additional 8 species of mammals also could occur based on range maps.
The most conspicuous bird
species are the waterfowl, particularly during migration. Peak
numbers of geese occur in January,
and peak numbers of ducks can be seen in November. Waterfowl
species nesting in the refuge
wetlands include blue-winged teal, gadwalls, mallards, black ducks,
wood ducks, exotic mute
swans, and resident Canada geese. A breeding bird survey conducted
on two tracts of the refuge
in 1996 recorded 85 species of birds nesting in the refuge’s forested
wetlands. The shallow waters
and marshes of the refuge provide excellent feeding areas for numerous
species of wading birds.
Shorebirds, gulls, and terns also use the refuge for foraging and nesting,
as well as numerous
raptors, of which the most predominant is the bald eagle. Largest
of the mammal species are the
two species of deer: the native white-tailed deer and the exotic
sika deer, both of which maintain
healthy populations on the refuge. Both muskrat and the
introduced nutria are thought to
contribute to marsh loss through their foraging activities. Efforts
to control these two species
have been on-going on the refuge for many years. Commonly observed
species of the secretive
reptiles and amphibians include the painted turtle, red-bellied turtle,
northern cricket frog,
southern leopard frog, and occasionally, a copperhead. Blackwater
also hosts a wide array of fish
species, and its marshes and estuaries are a spawning and nursery ground
for commercial and
sport fin and shellfish. However, present knowledge of the fisheries
resources is inadequate.
Blackwater NWR has also historically provided habitat and protection
for three federally
endangered species: the bald eagle, the Delmarva fox squirrel, and
the peregrine falcon. The
refuge's forests provide unique and important habitat for the largest
aggregation and nesting
population of bald eagles north of Florida, and the nation's largest
protected population of
Delmarva fox squirrels. Bald eagles and Delmarva fox squirrels are
year-round residents, while
peregrine falcons are occasionally observed migrating through the mainland
marshes of
Blackwater, but frequently visit Bishops Head Point and Spring Island
from nearby nesting towers
on Fishing Bay WMA, South Marsh Island Management Area, and Martin
NWR. In 1996 and 1997, record
numbers of eagles were produced in Dorchester County. In 1996
, a total of 80 eagles were
produced, 19 of which were from 12 nests on Blackwater NWR. In
1997, 92 eagles were produced, 24 of
which were from 14 eagle nests on the refuge. The Delmarva fox
squirrel, which now only inhabits
approximately 10 percent of its original range, appears to be stable
on the refuge. The red-
cockaded woodpecker, once found on Blackwater NWR, has not been sighted
since 1976, and is now
believed to be extinct in Maryland. The Northeastern tiger beetle
is believed to have suitable
habitat on Barren Island; however, no specimen has been found to date.
Sea turtles such as the
endangered Atlantic loggerhead, green, hawksbill, leatherback, and
Atlantic ridley are
occasionally found in the waters surrounding Barren Island, Bishops
Head Point, and Spring
Island. Several Species in Need of Conservation also occur on
Blackwater NWR: the black rail,
Henslow's sparrow, sedge wren, northern harrier, carpenter frog, rare
skipper, and sweet-scented
ladies-tresses. The adjacent Fishing Bay WMA provides important
habitat for three federally
endangered species, two federal candidate species, and six State-listed
species in Need of
Conservation.
C. Socio-economic/Cultural Resources
1. Socio-economic Resources
Dorchester County had a 1990 population of 30,236. Cambridge,
to the north of the refuge, is the
largest city in the county. While the county’s economy has historically
been based on agriculture
and water-related industries, manufacturing currently provides 36 percent
of the county’s
employment. Service and retail trade industries primarily provide
the balance of the county’s
employment. Timber is one of the county’s leading agricultural
industries. Approximately 142,000
acres of commercial timber exist in the county, the majority (80%)
of which is south of Route 50.
Average household income for the County is $35,368 (Dorchester County
1997). Shellfish and finfish
in the surrounding waters and furbearers in the marshes have always
provided a source of
livelihood since the time of the earliest settlers. Fur trapping
is a major source of supplemental
income to many Dorchester County residents, particularly watermen and
farmers. Waterfowl
hunting is a major recreational activity and industry around the Chesapeake
Bay area. State and
federal waterfowl refuges, including Blackwater NWR and Fishing Bay
WMA, are important in
maintaining and protecting the waterfowl resource. During the
1996 waterfowl season, over
140,000 ducks and 8,000 resident Canada geese were harvested by Maryland
sportsmen. (The Canada
goose season has been closed to taking migrant Canada geese throughout
the Atlantic Flyway
since the 1995 hunting season.)
The signing of the National Wildlife Refuge System Improvement Act of
1997 sanctioned hunting,
fishing, environmental education, wildlife interpretation, wildlife
photography, and wildlife
observation as priority uses of the National Wildlife Refuge System.
Recreational opportunities
on and around the refuge will be continued so long as they are compatible
with primary refuge
purposes and are consistent with objectives and wildlife management
programs. Refuge visitors
account for approximately $12.5 million dollars to the economy of Dorchester
County. Those who
are engaged in wildlife observation and photography are a rapidly growing
segment of the
population whose contribution to the economy is also substantial.
The refuge provided hunting
opportunities for over 1500 deer hunters in 1997. Sportsmen contribute
substantially to the
economy of an area through local purchases of gas, food, lodging, and
supplies. In an effort to
control nutria and muskrat populations on the refuge, trapping is conducted
on eighteen units,
which are awarded by sealed bids. Over $9,400 were bid for 1997
trapping rights. Trapping income
from the refuge in 1997 contributed approximately $30,000 to the local
economy. Blackwater NWR
also offers a comprehensive and structured wildlife interpretive and
education program with
exhibits and regularly scheduled public activities. Teachers
workshops, field trips, interpretive
foot trails, a five-mile interpretive tour route, interpretive exhibits,
and demonstrations, etc., are
used to increase public awareness of the area’s natural resources.
In fiscal year 1997, total visits to
the refuge exceeded 142,700.
2. Cultural Resources
The entire Chesapeake Bay area has a long history, and prehistory, of
human use. Both Indian
occupation and the white man’s settlement have been well documented
since colonial times. The
Staplefort cemetery at Blackwater NWR is considered to be historically
significant. Prehistoric
Indian sites exist on Barren Island. Brick foundation remnants
of pre-refuge home sites occur in
various wooded locations on Blackwater NWR.
5.0 CONSEQUENCES OF THE ACTION (See Table 1 for Summary
Matrix)
5.1 NO ACTION ALTERNATIVE
5.1.1 Aesthetics:
This alternative will likely invoke many different responses.
Resource managers, adjacent landowners receiving
and not receiving damages, the
general public, and waterfowl hunters will
all have different views and reactions to this
alternative. Resource managers will
continue to be plagued with increasing numbers of
resident Canada geese, and the resultant proportional
increase in damages to wildlife
habitats. The wildlife acceptance capacity
will be exceeded. Adjoining farmers, who
currently are experiencing agricultural crop
depredation, can be expected to be
frustrated and will likely seek permits to
control resident geese. Stakeholders not
receiving damage, such as animal rights activists,
and others who believe it is morally
wrong to kill animals for any reason, will
likely prefer this alternative. There certainly
will be increased numbers of resident Canada
geese to photograph and observe under this
alternative, but at some point their numbers
will definitely increase to the levels that the
biological carrying capacity of refuge habitats
is so greatly exceeded that the diversity
and abundance of wildlife is reduced and the
expansive marshlands are no longer
aesthetically appealing. The uninformed and
unaffected public would likely favor this
alternative, but again, the aesthetic value
would eventually diminish as more and more
geese soil the wildlife drive, nature trails,
lawns, parking lots, etc. A few waterfowl
hunters may benefit from increased numbers
of geese by taking less effort to fill the
legally allowed daily bag in the early season.
But generally, September goose hunting in
Dorchester County is not an established tradition.
Furthermore, many landowners are
actively feeding pen raised and released mallards
during this period on their Regulated
Shooting Areas. Hunting of resident Canada
geese, while feeding the free flying mallards,
would be in violation of the Migratory Bird
Treaty Act.
5.1.2 Animal
Welfare: Since there would be no action taken to control
the resident geese, there would be no concern
for animal welfare expressed except by
resource managers who would realize that no
control would eventually lead to
overpopulation, disease, malnutrition, and
disregard to the health and welfare of the
wide diversity of other wildlife that depend
upon the refuge for food and shelter. While
the general public and certain non-government
organizations may assume that no
control means no effect on animal welfare,
no control will have adverse impacts on
animal health. Migratory waterfowl would be
the first to be impacted, since the
uncontrolled population of resident geese
would soon eliminate the production of
moist soil plants and agricultural crops,
and will eventually destroy the natural marshes
used to supply nutrition for the refuge's
thousands of migrating and wintering
wildfowl.
High populations
can devalue the species. This has happened to Canada geese in some
areas.
Several northern New Jersey communities have
passed resolutions to 'delist' the Canada
goose from the Migratory Bird Treaty Act.
It is not unusual to encounter lake front
property owners referring to Canada geese
as flying rats. This disregard can lead to
citizens taking the law into their own hands,
and implementation of actions that do not
consider animal welfare, such as indiscriminate
poisoning.
5.1.3 Effects
On Human Health and Safety: The potential
threat to humans from contacts with fecal
materials would increase correspondingly
with a growing population of geese.
People would be less willing to use recreational areas
because of the increase in feces. As
more geese try to find nesting sites, there will also be
the likelihood of more geese nesting along
the wildlife drive and along refuge marsh
trails, thereby increasing the threat of attacks
on children and adults by nesting geese.
Most of the public would be frustrated that
degradation of public facilities supported by
taxpayer dollars would be allowed to continue,
and that government officials would do
nothing to minimize the potential for goose
attacks on humans. Although not a problem
at Blackwater, high populations of flightless
geese can pose a threat to automobile traffic
when they are drawn across public roads.
High populations can also pose a serious safety
hazard when they concentrate near airports.
5.1.4 Biological Impacts: Resident Canada geese would
continue to
increase in abundance over time in their protected environment,
would continue to displace
other wildlife, would eventually preclude the refuge from planting any
agricultural crops to meet the nutritional needs of migrating and wintering
wildfowl, and would exacerbate the loss of marsh that is already imperiled
by sea
level rise, land subsidence, and overgrazing by nutria. Water quality will
be
negatively impacted because of the increase in fecal droppings. Increased
erosion
from excessive grazing would negatively impact water quality and cause
increased
sedimentation and destruction of freshwater impoundment dikes.
The presence
of large numbers of resident Canada geese certainly conflict with
management of the wild, migratory Atlantic
Population (AP) of Canada geese. From food
production to wildlife surveys, the refuge's
management programs are adversely affected
by large populations of resident Canada geese.
Food and habitat for AP geese become food
and habitat for resident geese, making it
more difficult to manage for migrant
populations as a result of the growing resident
geese which quickly degrade and decimate
these resources that are important for the
health and survival of wild geese. Even the
accuracy of AP goose surveys is reduced because
of the growing number of resident geese
which, by winter, become indistinguishable
from wild birds and therefore adversely affect
population estimates. Left unchecked and uncontrolled,
the resident Canada goose
population would eventually keep the refuge
from accomplishing the purpose(s) for which
it was established, and would adversely affect
other wildlife species diversity and
abundance.
5.1.5 Economic Impacts: As populations increase, resultant
habitat
destruction and loss on the refuge will force geese to
adjacent private lands causing increased
damage to property. There will be increased damage to lawns and turf
at homes,
businesses, and golf courses. Agricultural losses to small grain,
corn, soybeans,
milo, and other crops will increase proportionate to the population increase.
As
populations increased off the refuge, landowners will either accept the
problems
or be forced to pay private pest control or nuisance wildlife control companies
to assist with damage management. While there would be no implementation
costs
since there would be "no action" to control populations, the refuge would
experience approximately $40,000 annually in crop depredation. The
refuge would
also experience significant decline in the number of visitors, which would
proportionately affect the $100,000 the refuge receives annually from entrance
fees
and book store sales.
5.1.6 Physical
Environment Impacts: There would be increased erosion
along
shorelines and
of dikes by increasing numbers of geese. There would be increased
potential
for long-term negative impacts related to
fecal contamination, and there will be
increasing number of complaints from visitors
to the refuge complaining about smelling
the odor associated with these overpopulations.
5.2 NON-LETHAL
PROGRAM ALTERNATIVE (Essentially the
Current Program)
Under this alternative,
only non-lethal management approaches will be used. Approved
methods potentially available to Blackwater
NWR for management of resident Canada geese
include habitat alteration/creation; physical
exclusion through wire grids, perimeter
fencing, and floating ball blankets; or frightening
and harassment methods such as
pyrotechnics, propane cannons, reflective
tape, flags, and chase dogs; and chemical
repellents. Relocation and contraception
are not approved methods of non-lethal
control in Maryland.
It should be
noted that although wire grids, perimeter fencing, and floating ball blankets
are methods potentially available, these
methods are not feasible or practical.
These methods are generally used on areas
of two acres or less. Resident Canada geese
currently occupy over 14,000 acres on the
refuge (a majority which is marsh and open
water), and even if it were feasible to use
these exclusion methods, they would be cost
prohibitive ($1,000 per acre for wire grids
and $131,000 per acre for floating balls) and
certainly would have significant impacts on
other wildlife and the public. Guard animals
or chase dogs may be used to frighten resident
Canada geese from areas where damage is
occurring. Dogs can have limited effectiveness
at harassing geese, but are normally used
on small areas without water where harassed
geese must go elsewhere to seek refuge.
Border collies have been trained to accomplish
this work. A well trained border collie
that will harass geese and not effect the
public or other wildlife (e.g. Delmarva fox
squirrels, etc.) costs approximately $2,000
to $4,000 per dog. Several dogs would likely be
necessary to be even somewhat effective.
Therefore, because of their limited effectiveness
on such a large area as the refuge and the
cost, this method was dismissed from use.
Therefore, wire grids, perimeter fencing,
floating ball blankets, and use of guard animals
are techniques and methods that will not be
used as part of this alternative.
5.2.1 Aesthetics:
Resource managers and adjacent landowners who are
receiving damage will experience high levels
of frustration with this alternative. As
proven at Blackwater for the past 9 years,
these techniques work for short periods of time,
do nothing to reduce population growth, and
geese soon learn that these methods will
cause no harm to them. In addition,
these techniques are often aesthetically unappealing
to the 150,000 visitors who use the refuge
(e.g. cannons exploding day and night, eye spot
balloons floating over all the agricultural
fields, mylar ribbon strung over all the fields
and blowing in the wind, and staff shooting
shell crackers and whistling bombs in areas
where geese and the visiting public are in
close proximity). In 1989, propane cannons were
sufficient to keep the 350 resident Canada
geese from damaging wildlife habitats and
concentrating on public use areas. However,
as the resident goose population increased
and competition for food was more intense,
geese quickly learned that an exploding
cannon meant no harm. The progressive addition
of other nonlethal harassment methods
were still ineffective (shell crackers and
whistling bombs, then mylar ribbon, and finally
eye-spot balloons). More and more effort
by refuge staff and the expenditure of more and
more money for harassment devices only resulted
in more and more geese. The wildlife
acceptance capacity was exceeded.
Stakeholders
not receiving damage, such as animal activists, might prefer this alternative
since no animals would be killed. As
for public not concerned with management actions,
the uninformed and unaffected would likely
favor this alternative. Refuge visitors would
certainly prefer not to see such annoying
visual detractors such as mylar ribbon and eye-
spot balloons everywhere. The public
will continue to observe geese in increasing
abundance just as in the No Action Alternative.
However, the aesthetics value would
decrease as more people are affected by damage
to their recreational areas and as feces
accumulates on areas frequented by the public.
Once the public is informed, they are likely
to reject this alternative because of the
ineffectiveness of methods and the fact that
harassment and exclusion can move geese to
private property. The public will also become
increasingly critical of the refuge for spending
appropriated funds on already
demonstrated ineffective methods. Furthermore,
as the population increases despite the
use of these techniques, the refuge's purpose(s)
will be impacted to the extent that the
refuge's mission can no longer be achieved
and objectives cannot be met.
Waterfowl hunters
may benefit from increased numbers of geese by taking less effort to
fill the legally allowed daily bag as geese
seek to find alternative feeding and resting sites
because of harassment. However, as previously
discussed, few geese actually leave the refuge
due to harassment, and additionally recreational
hunting of resident geese is not a high
priority on private land around the refuge.
Harassment simply will not equate to more
geese being killed by recreational hunters
on private lands in numbers sufficient to
alleviate damage (as proven during the last
two hunting seasons).
5.2.2
Animal Welfare: The would be concern among resource managers,
stakeholders, and the public if harassed adult
geese became separated from goslings.
5.2.3
Effects on Human Health and Safety: Consequences
would be the same as 5.1.3. Use of non-lethal
methods may redistribute some waterfowl to
other areas without financial resources to
get rid of the waterfowl or to areas where
waterfowl have become habituated to these
methods.
5.2.4 Biological Impacts: Same as 5.1.4.
5.2.5
Economic Impacts: Generally, the same as 5.1.5, except that
implementation costs would be much greater.
Based on past experience, these efforts will
require the annual expenditure of 1.0 to 1.5
staff years of effort and $2,000 to $3,000 in
harassment materials and supplies.
Yet, since the overall effect on refuge habitats and
wildlife populations will be negligible, the
refuge will still experience $40,000 annually in
crop depredation and the loss of revenue (as
much as $100,000 per year) from tourism
(entrance fees and book store revenue).
5.2.6 Physical
Environment Impacts: Same as 5.1.6
5.3 LETHAL PROGRAM ALTERNATIVE
For this alternative,
only lethal direct control will be used. Approved lethal methods
potentially available to Blackwater NWR for
population reduction of resident Canada
geese include public hunting, nest/egg destruction,
and capture and euthanasia, and are
all part of this alternative. Chemical toxicants
are not an approved method of lethal
control, and are not part of this alternative.
Implementation
of this alternative would result in a definite sequence of the lethal
control actions, beginning with egg addling/oiling/puncturing
in March and April;
followed by capture and euthanasia of goslings
in May and June; drive trapping and
euthanasia of molting adults and flightless
juveniles in June and July; rocket netting and
euthanasia of adults and flighted juveniles
in August; and public hunting in September.
5.3.1 Aesthetics:
Resource managers and adjacent owners who are receiving
damage would favor this alternative since
it would alleviate the most damage in the
shortest amount of time if appropriately applied.
However, some adjacent landowners
might eventually question this approach as
fewer and fewer geese were observed on their
property (not all adjacent landowners who
receive damage would want to see "all their
geese" killed). Nearly all stakeholders
not currently receiving damage would be very
concerned with this alternative, since every
goose, regardless of age or size, would be
killed. Animal rights activists would
be vigorously opposed to this alternative, and there
would be fewer and fewer geese to view in
future years. The public would not likely favor
a program that only focuses on killing wildlife.
Public ability to view and aesthetically
enjoy resident Canada will be limited as fewer
geese occupy the refuge, yet a reduced
population will result in a higher level of
wildlife acceptance capacity.
Public hunting
will result in very mixed reactions by both the hunters and the general
public. Because the majority of resident
Canada geese concentrate in the agricultural
units and fresh water impoundments immediately
adjacent to the wildlife drive,
implementation of this alternative would necessitate
closing the refuge's wildlife drive
to coincide with the State's early resident
Canada goose hunting season in September. This
action will eliminate use of the wildlife
drive for 10 consecutive days and two weekends
during one of the refuge's busiest public
use seasons. Approximately 2,400 visitors will be
excluded from participating in wildlife observation,
photography, interpretation, and
environmental education in order to accommodate
a maximum of 12 hunters per day (the
number that can safely hunt in this area).
Waterfowl hunters will be pleased because they
are being afforded a new opportunity to hunt,
however, they will not be pleased that
other forms of lethal control are being used
before and after their hunting season.
Hunters will strongly oppose other lethal
methods since they will most likely want a
large, sustainable population of resident
Canada geese to perpetuate their sport. Based on
reports from E.B. Forsythe NWR and Tudor Farms,
a private hunting preserve adjacent to the
refuge, hunters are also very likely to be
disappointed after the first day's hunt because the
resident geese are quick to learn to avoid
areas where hunting is allowed (particularly
since the geese have abundant food resources
outside the hunting area during that time
of the year). According to their experiences
and the experiences of other September goose
hunters, geese normally will provide shooting
opportunities only once (maybe twice) in
the 10 day period in any given field. Hunting
is also not a very effective or economical form
of control as noted by E.B. Forsythe NWR where
762 hunters, hunting 3,866 hours in three
years during state seasons, removed only 413
resident Canada geese from the refuge's
impoundment system. Off-refuge hunters are
also likely to be concerned because fewer
geese are leaving the refuge due to the reduced
population resulting from the
combination of lethal actions.
5.3.2
Animal Welfare: Resource managers and the public would support
humane capture when it results in no pain
or a minimum of pain that would be measured
as "sustaining physical injury" (e.g. bleeding,
broken wings, heat stress, and overcrowding).
Capture, where birds are made as comfortable
as possible by feeding, watering, proper
containment (no overcrowding), and cooling,
would be acceptable to resource managers
and the public. Euthanasia, in accordance
with AVMA methods and Maryland policy, would
generally be acceptable to this group.
If geese were shot by hunters, resource managers
and the public would expect clean kills.
Resource managers and the public would support
egg addling, oiling, and puncturing.
The concern among
stakeholders not receiving damage would be similar to resource
managers and the public, except for animal
activists who would want no geese captured
or killed regardless of the humaneness of
methods and proper husbandry. Some animal
activist would approve of egg addling, oiling,
and puncturing.
5.3.3
Effects on Human Health and Safety: The threat of
disease transmission from waterfowl to humans
would decrease because humans would
come in contact with fewer goose dropping
from a decreasing waterfowl population.
Potential attacks on children and adults from
nesting pairs would decrease likewise for
the same reason.
5.3.4
Biological Impacts: The resident Canada goose population will
definitely be reduced on the refuge. As the
refuge population is reduced, other resident
geese from adjoining private lands and waters
will be expected to fill the vacant habitat
made available by management actions over
time. From 1989 to 1998, the State resident
Canada goose population increased from 25,000
to 90,000. Maryland's population objective
for resident Canada geese is 30,000. The maximum
level of reduction authorized by the State
of Maryland for the refuge will not exceed
3.5% of the statewide population in any given
year. FWS has recognized that since
Canada goose populations have demonstrated the
ability to sustain annual harvest rates in
excess of 20% there would be little to no
cumulative impact of this action on the Statewide
population. However, local populations
would remain low, but stable in number if
lethal management was conducted on a regular
basis. Migratory waterfowl would benefit from
this alternative.
All the lethal
actions, except public hunting, will be accomplished by FWS personnel.
There
should be no indirect or direct impacts to
non-target species from egg
addling/oiling/puncturing; capture; or euthanasia
(which will only take place in
controlled environments). There might
be some direct impact to non-target wildlife
through hunting, but this should be minimized
through education; Canada geese are very
hard for the educated hunter to confuse with
other birds. Indirectly, however, other
wildlife will be adversely affected by goose
hunting in the impoundments, marshlands, and
croplands if for no other reasons than disturbance
and harassment.
5.3.5
Economic Impacts: There would be significantly reduced habitat
and property damage to affect resource managers
and adjacent landowners. Agricultural
losses would decrease proportionately with
the decrease in population. The potential for
health risks associated with goose droppings
would be reduced thus reducing health
costs. Implementation costs, while initially
reduced, would increase significantly over
the years as birds become lower in abundance,
wiser, and harder to kill per staff day of
effort.
5.3.5
Physical Environment Impacts: With this alternative there
is the potential for reduced erosion of dikes
due to overgrazing by excessive numbers of
resident Canada geese during the growing season.
There is also the potential for reduced
long-term negative impacts related to fecal
contamination of water sources which are
populated with large numbers of geese, and
the potential to reduce concerns related to
airborne odor from goose droppings.
5.4 INTEGRATED
WILDLIFE DAMAGE MANAGEMENT PROGRAM
ALTERNATIVE (PROPOSED ACTION)
Proposed control
methods and the timing/sequence of these methods have been discussed
in Section 3.2 and 3.4. A combination of nonlethal
and lethal methods will be used in this
alternative. When lethal methods are used,
all resident geese that are to be captured will
be captured alive using drive traps or rocket
nets. Drive trapping is conducted by simply
positioning standers and drivers along a previously
constructed fence and calmly
herding geese towards a capture pen located
in the middle of this funnel. Drive trapping
is only effective from mid-June to mid-July
when the juveniles are still flightless and the
adults have molted their flight feathers.
The success of drive trapping is highly dependent
upon the geese being in the right place at
the right time since the traps (fences and capture
pens) are stationary and cannot be easily
repositioned once in place. Rocket nets, on the
other hand, are more mobile, and are required
to capture resident geese when they have
regained their ability to fly. Rocket
nets are shot over the geese when they come to feed
on the bait that has attracted them to the
rocket net site. As previously explained, the
captured geese are individually placed into
well ventilated crates, under the most
humanely conscientious conditions, and subsequently
transported to a certified
processor. The processor, not refuge
personnel, euthanizes the geese in accordance with
AVMA procedures in accordance with Maryland
DNR and USDA policies. The processed meat
is then required to be donated to a charitable
organization for human consumption. One
such organization that has been contacted
is "Farmers and Hunters Feeding the Hungry"
(consult www.fhfh.org).
5.4.1 Aesthetics:
Resource managers favor this alternative beyond all
others because it provides the most options
to reduce damage, and the ability to choose
among the most methods to craft solutions
specific to balancing the social and economic
needs and the wildlife acceptance values of
the public. While there would be less geese for
the visiting public to see, geese would still
be available for wildlife observation and
photography and without mylar ribbon and eye-spot
balloons in the background. This
alternative is recognized as having the most
potential for long-term positive impacts for
wildlife managers and the general public.
Impacts to stakeholders not receiving damage
would be highly variable. Some stakeholders
would see the need to let the refuge manage
damage, and let the refuge choose the most
appropriate method (nonlethal or lethal).
Other stakeholders, particularly animal rights
activists, would oppose the privilege of
choosing any lethal management options.
A minority of animal activists would also
oppose all damage management involving wildlife
management (harassment, etc.).
Waterfowl hunters, who would like to hunt
resident Canada geese on the refuge, will
oppose this alternative since public hunting
will not be allowed. A few waterfowl hunters
may feel their hunting opportunities near
the refuge would be less since lethal control
will be implemented. Other waterfowl
hunters may benefit by harassment activities that
cause resident geese to avoid or leave
the refuge.
5.4.2 Animal Welfare: Same as 5.2.2 and 5.3.2.
5.4.3 Effects on Health and Safety: Same as 5.2.3 and 5.3.3
5.4.4
Biological Impacts: Same as 5.3.4, except that recolonization will
be slower because of the ability to use the
available wildlife management methods. Since
public hunting is not part of this alternative,
there should be no impacts to non-target
species. Furthermore, this alternative
will not permit the use of sedating drugs such as
alpha chloralose, and therefore, there will
be no impact on non-targets from using this
type of control methodology. Migratory
populations of waterfowl will benefit from this
proposal as will the refuge's purpose(s) and
objectives.
5.4.5
Economic Impacts: The overall economic effect would be a
reduction in costs caused by damage and implementation
of control programs. There
would be a reduction in agricultural losses
and in the threat to human safety as these
threats diminish proportionately with the
decrease in resident geese. The cost to manage
damage would decrease.
5.4.6
Physical Environment Impacts: Same as 5.3.6.
6.0 THREATENED AND ENDANGERED SPECIES
Methods used in the proposed action will have no effect on any
listed species.
7.0 Literature Cited
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or various agencies and the need for
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Conover, M.R. and G. G. Chasko. 1985. Nuisance Canada geese problems
in the eastern United States.
Wildl. Soc. Bull. 13:228-233.
Converse, K.A. and J.J. Kennelly. 1994. Evaluation of Canada goose
sterilization for population
control. Wildl. Soc. Bull. 22:265-269
Decker, D.J. and L.C. Chase. 1997. Human dimensions of living with
wildlife - a management challenge
for the 21st century. Wildl. Soc. Bull. 25:788-795
Decker, D.J. and G.R. Goff. 1987. Valuing Wildlife: Economic and Social
Perspectives. Westview Press.
Boulder, Colorado, p. 424.
Decker, D.J. and K.G. Purdy. 1988. Toward a concept of wildlife acceptance
capacity in wildlife
management. Wildl. Soc. Bull. 16:53-57
Heinrich, J.W. and S.R. Craven. 1990. Evaluation of three damage abatement
techniques for Canada
geese. Wildl. Soc. Bull. 18:405-410
Leopold, A.S. 1933. Game Management. Charles Scribner & Sons. NY,
NY. 481 p.
U.S.D.A., A.P.H.I.S., ADC. 1994. Animal Damage Control Program. Final
Environmental Impact Statement. 3
Volumes. Washington, D.C.
Wildlife Society, the. 1990. Conservation policies of the Wildlife
Society. The Wildlife Society. Wash.,
D.C. 20 p.
Pendleton, E.C. and J.C. Stevenson. 1983. Investigations of marsh losses
at Blackwater Refuge. Horn
Point Environmental Laboratories, Center for Environmental and Estuarine
Studies, University of
Maryland, Cambridge, M.D. 151p.
Tiner, R.W. and D.G. Burke. 1995. Wetlands of Maryland. U.S. Fish and
Wildlife Service,
National Wetlands Inventory. 193p.
Whiteman, R.L. and B.P. Onken. 1994. Protecting Delmarva fox squirrel
habitat from gypsy moth and
southern pine beetle, Blackwater National Wildlife Refuge. USDA Forest
Service, Morgantown, WV. 46p