|ARCTIC ECOSYSTEMS IN PERIL: REPORT OF THE ARCTIC GOOSE HABITAT WORKING GROUP
EVALUATION OF THE ARCTIC GOOSE MANAGEMENT INITIATIVE
DONALD H. RUSCH, Wisconsin Cooperative Wildlife Research Unit, 226
Russell Labs, University of Wisconsin, Madison, WI, 53706, USA.
F. DALE CASWELL, Canadian Wildlife Service, Winnipeg, Manitoba, CANADA.
The aim of the monitoring program for the Arctic geese and habitats is
to provide the means for evaluating progress toward habitat protection and
goose population goals. Our current model of goose- habitat interaction
supposes that low harvest rates of geese lead to high adult survival which
leads to population growth which in turn causes habitat degradation. We
propose to monitor each of these four important components of the
interaction model; i.e., harvests, adult survival, goose populations, and
status of the tundra habitats. The present proposal deals primarily with
white geese but monitoring of other goose species is also required.
Populations of large geese breeding in the States and southern parts of
the provinces are growing even faster than white geese, provide more
hunting opportunity and have the potential to cause ever greater
conflicts. The mix of Giant Canadas with other wintering populations
requires intensive harvest management (Rusch et al 1996). Annual banding
and populations estimates are crucial parts of the derivation process used
to estimate harvests of the large Canadas.
Harvests of geese are monitored in Canada and the United States by
questionaires to hunters and analysis of tail fan collections. Reasonable
estimates of white goose harvests can be obtained from these surveys, but
colony-specific estimates are not feasible at this time.
Colony-specific harvest estimates could be obtained by derivation
analysis (weighted band recovery methods). These require that all breeding
colonies are banded and their numbers are estimated. These conditions are
not currently being met on any breeding colonies.
The parameter that influences goose survival is harvest rate (HR).
Harvest rate can be estimated from the direct band recovery rate (DBRR)
and the presumed reporting rate (HR1=DBRR/RR-seeH-f/F, pp 94-96) or from
the quotient of harvest and fall flight estimates (HR2=Harvest/Fall
Flight). An increase in goose harvest rates is the primary and most
important management strategy. We recommend that both HR1 and HR2 be
estimated: 1) for snow geese at the metapopulation level (i.e., Western,
Central and Eastern Arctic).
We believe that adult survival of snow geese is primarily a function of
harvest rate, and that increase HRs will lead to reduced adult survival.
Alternatively, increased harvest rates may be compensatory rather than
additive. Adaptive management requires knowledge of the harvest
From the standpoint of demographic analysis of goose populations,
sufficient geese should be banded or marked to provide precise survival
estimates for young and adult geese of each colony or population. Ideally
banding would be conducted annually to generate year-specific recovery and
survival rates and information on distribution and derivation or harvest.
Because of costs and the long-term nature of the initiative, we therefore
propose that Arctic banding should be conducted and coordinated with
population surveys, and that monitoring efforts should rotate among sites
over a period of three years. In the eastern Arctic, for example, snow
geese would be estimated and banded at McConnell River, Southhampton
Island and Baffin Island on a three-year rotation. We recommend annual
banding and surveys of white geese at Cape Hennrietta Maria and La Perouse
Bay. Banding goals would be 5,000 adults per year.
Large sample sizes would allow estimation of annual survival rates for
adults at the metapopulation level (i.e., Eastern Arctic, etc.) Direct
recovery rates and survival rates of young would be also estimated at the
We believe a program to enhance the reporting rate of harvested bands is
an important part of any Arctic banding program. At present, the cost of
banding at a colony in the Arctic ranges between $50,000 and $100,000
depending on the remoteness of the location. If 1000 geese were banded at
a remote colony, costs could be as high as $100 per goose. If the average
direct band recovery rate is 3%, about 15% of the bands are eventually
recovered; thus each recovery would cost about $750. Rewards of up to $200
per band or other similar expenditures to enhance reporting are cost
effective for Arctic geese.
POPULATION INDICES AND ESTIMATES
The midwinter index is the primary historic and current method of
monitoring numbers of snow geese. These indices should continue because
they provide valuable long-term trend data at the continental level.
Midwinter indices suffer because 1) counts are imprecise due to difficulty
counting large numbers and in achieving complete coverage of all areas;
and 2) geese counted in winter are aggregations of birds from many
colonies, populations and flyways.
Spring and Summer Surveys
We believe that numbers of geese should be estimated on the breeding
areas wherever possible. We propose that numbers of snow geese in each
colony be estimated once every 3 years from aerial photography or from
helicopters flown on stratified transects. Due to lack of consistent
funding, only a few helicopter surveys have been flown and aerial
photography has been sporadic. Some eastern Arctic colonies have not been
surveyed since 1978. Surveys conducted with banding are an option to
consider for remote colonies. August helicopter transects can provide
estimates of breeding geese, nonbreeding geese, proportion with young and
young per successful adult. Stratified transects flown from helicopters
also provide opportunities for banding random samples. Coordination of
August surveys and banding would eliminate one or two additional
expeditions to remote Arctic colonies.
COASTAL TUNDRA HABITAT
Protection of coastal tundra habitats is the ultimate goal of the
proposed goose management strategy, and some habitat monitoring is
essential. We propose that the permanent plots established around James
and Hudson Bays be expanded throughout the Arctic in coastal tundra
habitats. These plots should be monitored on an annual schedule to detect
vegetation trends, to elucidate goose vegetation- weather-climate
relationships and to provide ground-truth data to permit development and
maintenance of habitat signatures for interpretation of satellite imagery.
Satellite imagery of about 20% of all coastal tundra should be obtained
and analyzed every year; thus each area would be "revisited"
every five years.
Progress toward program goals should be evaluated annually. The annual
evaluation report should describe objectives, strategies and activities
and provide preliminary description of progress toward goals. A
comprehensive analysis of harvest rates, survival rates, population trends
and habitat condition should be conducted every five years.
The five year evaluation should provide detailed quantitative analyses
of harvest, survival, population and habitats; and the interactions among
these estimates and other environmental variables.
Rusch, D., F. D. Caswell, M. M. Gillespie and J. O. Leafloor. 1966.
Research contributions to managment of Canada geese in the Mississippi
Flyway. Pp. 161-173 in Transactions of the 61st North American Wildlife
and Natural Resources Conference.
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