Topic: Mid-continent populations of Snow Geese and Ross' Geese
Background: For several years, researchers have expressed concern about the effect of rapidly-expanding mid-continent populations of Snow Geese and Ross' Geese on Arctic vegetation. Following a report by the Arctic Goose Habitat Working Group of the Arctic Goose Joint Venture of the North American Waterfowl Management Plan (Batt, B.D.J., editor. 1997. Arctic ecosystems in peril: report of the Arctic Goose Habitat Working Group, Arctic Goose Joint Venture Special Publication. U.S. Fish and Wildlife Service, Washington, D.C. and Canadian Wildlife Service, Ottawa, Ontario. 120 pp.) and a series of public meetings, the U.S. Fish and Wildlife Service concluded that population reductions were needed and undertook to develop appropriate regulatory measures.
Additional information is available on the U.S. Fish and Wildlife Service website at http://www.fws.gov/r9mbmo/issues/snowgse/tblcont.html
Comments filed by the Ornithological Council
Updates:
President Clinton signs legislation allowing management plan to go forward (29 November 1999)
Management plan withdrawn pending preparation of Environmental Impact Statement (2 April 1999)
Management plan announced (16 February 1999)
PRESIDENT SIGNS SNOW GOOSE BILL TO PROTECT ARCTIC HABITAT
President Clinton has signed legislation reinstating interim
population control measures for mid-continent light geese
implemented last winter and spring by the U.S. Fish and
Wildlife Service. As directed by the legislation, the Service will notify
24 Midwestern and Southern states that they are allowed
to take conservation measures in the winter and spring of 2000 aimed at
reducing the population of mid-continent light geese.
Designed to halt widening destruction of fragile arctic migratory bird breeding habitat caused by exploding populations of lesser snow and Ross' geese, the measures were implemented on Feb. 16, but were withdrawn in May after a legal challenge.
The Service has since begun work on an Environmental Impact Statement that will determine its long-term management strategy for overabundant lesser snow and Ross' geese populations, as well as the rapidly increasing greater snow goose population. A draft EIS is expected to be completed in the Spring of 2000, with a final EIS anticipated next summer. Congress' action will not affect the Service's work on the EIS.
Concerned that the length of the EIS process would leave
the Service and state wildlife agencies without the ability to take
action next spring, Rep. Jim Saxton, R-N.J., chairman
of the House Resources Subcommittee on Fisheries and Wildlife,
introduced legislation in July that reinstated the rules.
The legislation gives states the ability to take measures to reduce
light goose populations pending completion of the EIS,
thus preventing a delay that only compounds the problem. The
legislation was approved by Congress on Nov. 10, and
signed by President Clinton on Nov. 24.
"We appreciate the support of Chairman Saxton and other members of Congress for our efforts to protect these priceless breeding grounds from further devastation. We have long understood the need to take action and have been working to implement a long-term management strategy as quickly as possible" said Service Director Jamie Rappaport Clark. "Our work on the EIS will go on, but the legislation gives states the ability to act in the interim to protect the priceless arctic habitat."
The measures give states in the Central and Mississippi
Flyways the flexibility to allow the use of normally prohibited
electronic goose calls and unplugged shotguns during
the remaining weeks of their light goose seasons in the spring,
provided that other waterfowl and crane seasons have
been closed. States have also been given the authority to implement a
conservation order under the Migratory Bird Treaty Act
that would allow hunters to take light geese after March 10, outside of
traditional migratory bird hunting season frameworks.
Both rules give states a better opportunity to increase their light goose
harvests.
Fourteen states implemented all or part of the population control measures last year, contributing to a harvest of mid-continent light geese estimated at more than 1.07 million birds for the 1998-99 season. That harvest represents a 46 percent increase over the 730,000 birds harvested in the Central and Mississippi Flyways during the previous season, when no conservation measures were taken. Estimates provided by participating states and compiled by the Service indicate that the special harvest provisions resulted in a combined harvest of more than 438,000 birds.
Increasing agricultural and refuge development along waterfowl
flyways through the Midwest and South has provided light geese with ample
forage during their yearly migrations. As a result, adult mortality rates
for light geese have fallen steadily over
the past three decades, triggering explosive population
growth.
Annual winter population counts of mid-continent light
geese estimate that the population has more than tripled in the past 30
years, from just over 800,000 birds in 1969 to approximately
2.8 million birds last winter. The fragile Canadian arctic, with
its
short growing season, cannot support populations of that
size. For example, large areas of the breeding grounds around Hudson Bay
have been denuded of all vegetation by geese through overgrazing, a situation
that scientists believe may also be
contributing to the decline of breeding populations of
other migratory bird species that share the breeding grounds and winter
in the United States.
The Bill's provisions take effect with the President's
signature. The Service will publish a future notice in the Federal Register
advising states of their ability to participate in the
conservation measures. State wildlife commissions must then
decide whether to participate, and under what circumstances.
Management plan withdrawn
The U.S. Fish and Wildlife Service announced 2 April
1999 that it will begin work this spring, one year earlier than originally
planned, on an environmental impact statement that will evaluate long-term
options for managing mid-continent light goose populations. By accelerating
the EIS process, the Service seeks to more fully analyze information and
alternatives, broaden the already strong consensus for action, and minimize
disruptions to state wildlife agency planning efforts.
In concert with the compilation of an EIS, the Service will withdraw final rules designed as a short-term measure to reverse ongoing destruction of arctic breeding habitats caused by exploding light goose populations. The withdrawal will occur after the end of the current spring migration and will not affect existing state conservation actions authorized by the rules.
In response to a legal challege filed by the Humane Society of the United States, Judge Thomas Francis Hogan ruled in favor of the Service on March 19 and denied a request by the group for a preliminary injunction blocking implementation of the rules. He found that the Service would probably prevail on its claim that it acted within its mandate under the Migratory Bird Treaty Act to take emergency measures to protect migratory bird resources.
But Judge Hogan did find cause to believe that a full environmental impact statement, rather than the more concise environmental assessment (EA) performed by the Service, is likely required by the National Environmental Policy Act.
"In respect to the government's decisionmaking process, it is clear that FWS acted in good faith. FWS' EA represents a hard look at the proposed action that comports with the spirit of NEPA, though not its letter," Judge Hogan said in his ruling.
"In his opinion, Judge Hogan acknowledged the thorough scientific analysis the Service and its partners conducted to help resolve this problem and the widespread support in the scientific and conservation community for the rules we are implementing," said Service Director Jamie Rappaport Clark. "We will build on this analysis by completing the EIS that he has suggested."
The rules, which were implemented February 16, gave 24 states the flexibility to allow the use of normally prohibited electronic goose calls and unplugged shotguns during the remaining weeks of their light goose seasons this year, provided that other waterfowl and crane seasons have been closed. States were also given the authority to implement a conservation order under the Migratory Bird Treaty Act that would allow hunters to take light geese outside of traditional migratory bird hunting season frameworks after the closure of all other waterfowl and crane seasons.
The Service had planned to commence an EIS next year, evaluating the long-term impacts of increased harvest and other potential control methods. While the EIS process is a lengthy one, the Service will complete its analysis as quickly as possible. The Service cannot assure that the EIS will be completed in time to support potential management actions in the spring of 2000.
Management plan announced
On 16 February 1999, the U.S. Fish and Wildlife Service
published a notice in the Federal Register stating that the proposed rule
and regulation would be made final and implemented. Twenty-four midwestern
and southern states will be permitted to take conservation measures aimed
at reducing the popultion of mid-continent light geese. The rules will
give these states the flexibility to allow the use of normally prohibited
electronic goose calls and unplugged shotguns during the remaining weeks
of their light goose seasons this year, provided that other waterfowl and
crane seasons have been closed. States have also been given the authority
to implement a conservation order under the Migratory Bird Treaty Act that
would allow hunters to take light geese outside of traditional migratory
bird hunting season frameworks. Both rules will give states a better
opportunity to increase their light goose harvests.
The Service is also changing the way it manages national wildlife refuges in the mid-continent region to make them less attractive to snow geese. The Service will seek input from its partners and other interested organizations and individuals to begin to determine the scope and participants for a long-term study of other potential control measures.
The Canadian Wildlife Service is currently conducting
its own regulatory impact analysis statement on the overabundant light
goose problem. The agency has also proposed regulatory changes for
the 1999/2000 hunting season for certain provinces that include a number
of the same measures that will be taken in the United States.
Comments by the Ornithological Council
15 January 1999
Robert Blohm, Ph.D.
Acting Chief
Office of Migratory Bird Management
U.S. Fish and Wildlife Service
4401 North Fairfax Drive
Arlington, VA 22301
RE: (1) Proposed rule to establish a conservation order
for the reduction of Mid-continent Light Goose populations
(2) Proposed regulation
to increase the harvest of Mid- continent Light Geese
(3) Draft Environmental
Assessment
Dear Dr. Blohm,
The Ornithological Council appreciates the opportunity to comment on the proposed rule, proposed regulation, and draft Environmental Assessment (EA) listed above (63 FR 60278, 60271; 9 November 1998). The Ornithological Council consists of nine leading scientific ornithological societies - The American Ornithologists' Union, Association of Field Ornithologists, Consejo Internacional para la PreservacRon de las Aves (CIPAMEX), Cooper Ornithological Society, Colonial Waterbird Society, Pacific Seabird Group, Raptor Research Foundation, Society of Caribbean Ornithology, and Wilson Ornithological Society - that together have a membership of nearly 6,500 ornithologists. It is our mission to provide scientific information about birds to legislators, regulatory agencies, industry decision-makers, conservation organizations, and others, and to promote the use of that scientific information in the making of policies that affect birds.
Before addressing the specifics of these actions and the EA, we would like to note that four of our member societies - the American Ornithologists' Union, Cooper Ornithological Society, Wilson Ornithological Society, and Association of Field Ornithologists - adopted a resolution pertaining the to mid-continent snow goose situation at the North American Ornithological Conference held in St. Louis in April 1998. Specifically, the resolution, which is enclosed, states that the 1997 report entitled "Arctic Ecosystems in Peril: Report of the Arctic Goose Habitat Working Group, " published by the Arctic Goose Joint Venture Management Board and Working Group (under the auspices of the North American Waterfowl Management Plan), has received adequate peer review. The resolution endorses the science-based recommendations of the Arctic Goose Habitat Working Group as necessary steps for reducing mid-continent snow goose numbers "to a level of about 50% of current numbers by the year 2005."
The resolution also recommends that the "Arctic Goose Habitat Working Group and other appropriate organizations to identify and develop solutions to the anthropogenic changes in environmental conditions that have led to the problem."
We do not dispute the conclusions of the Working Group that control measures are warranted or that the population would be most responsive to control via an increase in adult mortality. To that extent, the measures reflected in the proposed rule and the proposed regulation are, in fact, science-based. However, we have two major concerns about the premises underlying both these measures and the EA that substantiates them. These concerns are:
Initially, we would like to draw attention to an issue pertaining to the determination made by the Service of the harvest rates needed to achieve the desired population reductions. After the resolution was adopted, we learned that there is a fundamental scientific dispute about the Working Group report. This dispute involves the accuracy of the determination of the harvest rate needed to bring about a population reduction of a certain size. This dispute is not discussed in the EA, although we are aware that it has been discussed by the authors of the Report. It is our understanding that the Service is aware of the dispute as a result of public discussions held in January 1998 at the North American Goose Conference. We feel it is appropriate to raise the issue for the record.
In a paper in press (submitted to the Canadian Wildlife Service as an occasional paper, Fred Cooke, Ph.D. and Evan Cooch, Ph.D. have re-examined the impact of hunting of population growth in mid-continent Lesser Show Geese. They state that the two key assumptions in the application of the model used by the Working Group (the "Rockwell model") could result in a miscalculation of the extent to which the kill rate must be increased in order to bring S down to below 1.0. Rather than the two-fold increase in current hunting mortality that the report estimates is needed to reduce population size, instead a four- to six-fold increase is needed.
The error identified by Cooke and Cooch has two sources. First, the Rockwell model calculated kill rates based on reporting rates (the probability that a band reported is from a banded, harvested bird). Reporting rates were available for birds banded at three different colonies. The Rockwell model uses the highest of these three rates without justification. Cooke and Cooch suggest that the higher rate may result from reporting bias, because the birds banded at that colony had colored leg bands, which is thought to result in a higher reporting rate. It is also possible, according to Cooke and Cooch, that the lower rates at one of the other two colonies result from the facts that aboriginal hunting pressure on this colony is significant and that aboriginal hunters rarely report bands. Whatever the reason, Cooke and Cooch assert that the reporting rates from the one colony are atypically high and should not have been used without justification. Second, the model assumes that harvest rates (probability that a bird is shot and retrieved) have not changed since 1983. If harvest rates remained the same, in a population that has continued to increase in size, then kill rates (the probability that a bird is shot and retrieved) actually declined to 2.0%. The Rockwell model assumes a kill rate of 8.0% and calculates that to achieve a l of 0.85, it is necessary to triple hunting mortality. To achieve a l of 0.95, the kill rate would have to be increased by a factor of 1.99 to 2.12. Cooke and Cooch calculate that to reach a l= 0.85, a 5.5 - 9-fold increase in the kill rate is actually needed. A 4- to 6-fold increase in the kill rate would result in l= 0.95.
The EA states that tripling the harvest rate (p.9) from its current rate should lead to the desired reduction in population size. We note that there is an apparent inconsistency in the EA in this regard. On p.9, the approximate total harvest rate for all flyways is given as 700,000 birds. The current rate of harvest, according to USFWS harvest data (p. 36) is stated to be approximately 587,000 Lesser Snow Geese and blue phase Lesser Show Geese in all three flyways - Central, Mississippi, and Atlantic. Together with the 20,100 Ross' Geese harvested, the 1997-1998 total harvest of MCLG is 607,900 birds. This is a discrepancy of approximately 13%. Even the lower figure, though, represents a harvest rate double the 305,000 used in the Rockwell model (Working Group report, p.99).
In other words, the Rockwell model concludes that the annual harvest rate of 915,000 birds would result in a reduction in population growth to l = 0.85, or about 615,000 birds to reach l = 0.95. The EA's conclusion that a harvest of 1.7 - 2.7 million birds (p.9) is needed to achieve a population reduction sufficient to halt the habitat destruction seemingly acknowledges that the Rockwell model required revision. It also appears to be consistent with the Cooke and Cooch conclusion that a 3.5 - 4.4-fold increase in [1983] harvest rates (between 1,067,500 and 1,342,000 birds) will result in l = 0.95 and that a 5.4 - 6.3 increase [in 1983 rates] (between 1,647,000 and 1,921,500 birds) will result in l = 0.85.
Concerns about the efficacy of the proposed actions and need to address underlying causes
The larger issues are:
The EA does not directly assess the population size that the available habitat can sustain, but the premise of the EA is that the population reduction goals of these measures will, in fact, reduce the population to a level that the remaining breeding habitat can sustain (p.9). This critical issue requires a stronger scientific bases. The EA states that when the December Index falls between 8,000,000 and 1.2 million MCLG, the proposed action will be discontinued. The EA presents no data or analysis to support a conclusion that this population size will prevent further habitat damage, and nothing to support the notion that it will allow regeneration of some or all of the vegetation types that have been damaged. More significantly, assuming that these management strategies are successful, they should be continued (although modified as needed, based on population monitoring). If they are discontinued, it is likely that the population growth will soon again reach the levels that have been problematic over the past thirty years. According to the Working Group report, the habitat changes at La PProuse Bay (which largely forms the basis of the descriptions of habitat changes in the report) were detected in 1978, when intensive studies of plant-herbivore interactions began (Working Group report p.44). At that time, the Western Central Flyway population of light geese was estimated to be about 90,000 (Working Group report p.32) and the mid-continent population was estimated to be about 1,500,000 (Working Group report p.31). The report states that it is clear that the changes there and elsewhere occurred much earlier than 1978, although it is very difficult to determine how much earlier. It is entirely possible that a much smaller population size, maintained over a longer period of time, will be needed in order to give the habitat time to regenerate.
Will the proposed rule and proposed regulation result in the projected population reductions?
The EA states that, "On the outside, we expect to harvest an additional 1 - 2 million MCLG annually with the implementation of the preferred alternative in this Environmental Assessment (Alternative 5), given assumptions regarding State and hunter participation and regarding the increase of harvest per hunter due to new hunting methods or an expanded time frame to harvest or both." If the Service is proposing to give this Alternative a five-year trial period, then there should be a greater degree of certainty that the Alternative will result in an increased harvest of this magnitude.
How much additional damage will occur in the next five years?
The EA should also discuss the time needed for habitat regeneration. It may be that the population reductions envisioned by the Service, even if attained, will not be achieved within the five years allotted for an assessment of the effectiveness of the proposed measures. The Working Group report notes that the rate of habitat damage has increased dramatically and has been extending across different vegetation types (p.44). If the proposed measures are not likely to result in population decreases quickly enough to slow the rate of habitat destruction, then additional alternatives should be considered. In addition to those discussed in the next section, other measures could include encouraging the Canadian Wildlife Service to allow increased hunting and egging by aboriginal people.
The root cause of the problem is not addressed
Finally, and most importantly, the EA fails to consider measures to address the underlying causes of the population increases. The EA notes that agricultural expansion in the mid-continental U.S. and prairie Canada was largely responsible for the increase in adult survival and increased production. However, it is not only the existence of those additional winter foraging areas that has resulted in the population increase. Rather, the deliberate management of those agricultural areas to promote healthy waterfowl populations appears to have been too successful with regard to Snow Geese and Ross' Geese. Additionally, the EA notes that the NAWMP population objectives for MCLG have been exceeded by nearly 1,8 million birds in the Western Central Flyway and mid-continent populations (p.6). However, the EA does not consider changes to these practices or to the NAWMP. Furthermore, there is no mention of the fact that most National Wildlife Refuges are managed primarily for the benefit of waterfowl. Changes in management strategies for these refuges to address the needs of other migratory birds and other species should be considered. It would seem essential to consider the root cause of the populations growth of these species in determining management strategies to control that growth.
Conclusion
While the Service is justified in proposing both this proposed rule and proposed regulation in the sense that population reduction is needed to protect the habitat, it is not clear, from a scientific point of view, that these actions will be sufficient in either the short term or over a longer period of time. Therefore, we urge the Service to make additional efforts to determine the population reduction needed to bring about regeneration of damaged habitat and to prevent a recurrence of that damage in the future. We also suggest that the Service consider ways to adjust refuge management to give more attention to taxa other than waterfowl. Incentives should be given to agriculturists to manage their lands for the benefit of a wider range of biological diversity rather than primarily for waterfowl.
The Ornithological Council again thanks you for the opportunity
to comment on this issue. We also thank the Service for its diligent efforts
to address this very difficult problem. We hope that these comments prove
useful.
Sincerely,
Ellen Paul
Executive Director
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