Because the Metro program has emphasized population management rather than short-term redistribution techniques, the methods used to evaluate methods differed. Data on short-term efforts were from interviews of individuals using a technique. In contrast, population management efforts were i ntensely studied, particularly capture and relocation, and capture and process.
Trap and Relocate
When the city of Minneapolis first requested assistance in
1982, the MNDNR elected to use trap and relocate to reduce a 500+ city park flock.
After the city developed and approved a plan, flightless geese were drive-trapped,
loaded in trucks, and moved to a holding pen. One hundred ninety five immatures were
banded and relocated 32 km SW of the site, and the remaining adults and young were
released in Oklahoma (Cooper 1987). Since that time, trap and relocate or trap and
process have been used at 195 sites in 47 cities.
To evaluate the effectiveness of relocation, molt period
populations were compared and the return rates of relocated, legbanded-geese
determined. Oklahoma was selected as the initial release area. Adults geese were
shipped to Oklahoma annually until 1992. Limited numbers of adults (<300) were
transported to Kentucky and Mississippi in 1989 and 1990, and larger (500-1,500)
groups went to Mississippi and Kansas during the 1992-94 period, and to Kansas in
1995. Except for 1984, when immatures were sent to Oklahoma, goslings were released
in Minnesota, South and North Dakota, and Iowa. Return of relocated birds to capture
sites was determined by banding, and subsequent reading of legbands with spotting
scopes, from trap recaptures, and from legband recoveries. The effect of goose
removal on goose numbers at problem sites was determined by comparing molt
populations at sites after 1-10 years of removal. Because nearly all geese present
at site were captured (Table 1), linear regression slopes (b coefficients) were used
to estimate population changes.
Table 1. Adult (A) and immature (I) Canada geese captured and removed from the Twin Cities of Minnesota, flightless goose capture efficiency, and mortality during trapping or transport, 1982-1994.
________________________________________________________________________ Capture Mortality Year I A Total PercentaI A Total Percent ________________________________________________________________________ 1982 195 261 456 99 2 0 2 0.44 1983 0 0 0 -- - - - ---- 1984 361 492 853 96 0 0 0 0.00 1985 507 396 903 99 1 1 2 0.22 1986 636 379 1,015 99 2 0 3 0.30 1987 740 375 1,115 97 1 0 1 0.09 1988 1,714 864 2,578 99 1 1 2 0.08 1989 1,680 1,294 2,974 97 2 1 3 0.10 1990 1,766 1,054 2,820 96 1 0 1 0.04 1991 1,685 1,196 2,876 96 3 1 4 0.14 1992 3,005 1,248 4,253 98 2 1 3 0.07 1993 2,224 1,083 3,307 99 1 1 2 0.06 1994 2,834 1,352 4,186 98 1 0 1 0.02 1995 4,747 2,189 6,936 96 6 2 8 0.12 1996 3,982 2,256 6,239 97 1 1 2 0.03 ________________________________________________________________________ Totals 26,076 14,439 40,515 25 10 35 0.09 ________________________________________________________________________ aPercent of flightless geese present that were captured.
Trap and Process
By 1992, states releasing adult geese indicated that they
were approaching population goals, and that future releases would be curtailed. In
1995, the MNDNR asked other state wildlife departments if they planned future
releases of adult Canada geese. Only Kansas indicated an interest in adults and only
for 1995. Concurrently, MNDNR Area Wildlife Managers reported that rural Minnesota
Canada goose populations were expanding and there would be limited gosling release
sites in the future. Thus, if population control through removal was to continue,
an alternative to relocation would be needed for adults by 1996 and for goslings a
few years thereafter. Because we found that citizens and city council members
frequently suggested that "eating the surplus geese" would be an acceptable
alternative to relocation, we conducted a food shelf feasibility study in 1995 and
1996.
The objectives of the processing 1995 pilot were to
determine the likelihood of contaminants, costs, social acceptability of slaughtering
geese, the demand and utilization of goose meat by food shelves, and the management
and funding needs for an operational goose processing program. In 1996, the
feasibility of finishing (holding the geese until body feather molt was complete) was
evaluated. Adult geese from the most industrialized area of the Twin Cities were
also tested for contaminants.
The 1995 study involved butchering 200 adult geese and
donating them to food shelves. One-hundred male and 100 brood-patch (Hanson 1959)
female adults were randomly selected from the 2,189 adults captured. Two USDA
approved waterfowl processors were located including 1 willing to process birds in
summer. Twenty-two birds were used to test the processing equipment and procedures,
75 geese were slaughtered in July, and 103 in September. An additional 125 adult
geese were processed in January 1996. These geese had originally been designated for
relocation to Kansas, but Kansas later declined to take them and an alternative site
could not be found. With USFWS approval, the MNDNR also processed these birds.
Weight gains and food consumed by the birds were determined and used to compute costs.
To assess the social acceptability of the proposal, the plan was given wide media
coverage, and public responses documented.
Because we believe that immature geese, captured when 3- to
7-weeks of age, cannot be effectively processed immediately after capture, and
because we found that adults processed in September had excessive pin feathers
precluding whole carcass utilization, 614 adult and 154 goslings were selected at
random, winged clipped, and placed on a fenced, 16 ha pasture with 2 well-water
ponds. These birds were processed in the mid-November, 1996.
Three brood patch females were chosen randomly from a group
of 36 adults capture at Pigs Eye Lake in St. Paul. Pigs Eye was the only the Meto
Area industrial location where geese were considered a problem. Breast muscles and
liver samples were analyzed by the Minnesota Department of Agriculture's contaminants
laboratory for PCBs, mercury, and organochlorine pesticides.
Special Hunting Seasons
In response to the growth of resident Canada geese in the U.S., the UFWS approved experimental special early and late hunting seasons in 1983. In Canada, Ontario began late season hunting in 1984 and early hunting in 1991 (Zenner 1996). Minnesota initiated experimental early and late seasons in the Metro in 1987; these seasons became non-experimental in 1991. Early seasons occurred during the first 10 days of September, prior to the arrival of migrant geese, with a 5-bird bag limit. Late seasons have also lasted 10-days beginning in mid-December with a 2-bird limit. Harvest data for these seasons were gathered by the MNDNR by mail survey.