Call it peace and quiet.
Migrating ducks, geese and swans were provided more resting and feeding areas, combined with less human disturbance, during their stop-over on the Upper Mississippi River National Wildlife and Fish Refuge during the fall of 2007.
The birds responded to new management actions that modified the current system of areas closed to waterfowl hunting along the 261-mile refuge.
“The closed areas are like stepping stones for the birds as they make their way south,”
said Eric Nelson, refuge biologist.
Nelson explained that, “the new system takes into account decades of survey work that has shown an unequal distribution of the birds, food and hunting opportunity in Pools 4-14 of the Mississippi River. Having all the ducks in a few pools is not ideal for the birds, nor ideal for waterfowl hunters.”
Birds concentrated in a few areas are susceptible to disease outbreaks, sudden habitat loss, and human disturbance. This concentration also means that the birds are not equally available for hunting or wildlife observation through the length of the Refuge.
The 2007 changes are part of the Refuge’s new 15-year Comprehensive Conservation Plan, approved in 2006. More high-energy food resources found in refuge backwaters were secured for the birds by adding new closed areas and modifying the boundaries of others.
To reduce disturbance, new management provisions do not allow the use of motors in closed areas less than 1000 acres in size and also ask people to voluntarily avoid entering all closed areas from October 15 to the end of the duck hunting season. Seven of 24 closed areas are less than 1000 acres.
Duck hunting success continued to be good even as new areas were closed to hunting.
7Birds Response Was Good in Most Places
One area with increased duck use was at the new Spring Lake closed area near Buffalo City Wis. in Pool 5. Canvasback and mallard use doubled over the 2006 counts when the area was open to hunting. Counts were made by airplane and ground crews.
Bird use also increased at the existing Goose no hunting zone which was expanded by 108 acres in 2007. Tundra swans, gadwalls, canvasbacks and redheads were more numerous than previous years.
At the new Wisconsin River Delta special hunt area near Prairie du Chien, Wis. in Pool 10, duck hunting was closed early, November 1, nearly a month after the season opener.
Bird numbers went from 460 birds (mostly coots) in October, to 2,652 (mostly mallards) by mid-November and reached a peak of 3,275 waterfowl in late November. In recent years, before the November 1 hunting closure was in effect, counts totaled only a few hundred birds.
Change in duck use was not as dramatic at the new Kehough Slough closed area in Pool 12, north of Bellevue Iowa and the new Beaver closed area in Pool 14, near Clinton, Iowa. These areas had a lack of food resources caused by late-summer flooding that killed aquatic plants and more high water in October that forced birds to move on.
At the existing Elk River closed area (Pool 13, near Sabula, Iowa), effects of new voluntary avoidance provisions on bird use were inconclusive. While aerial surveys showed 40% more puddle duck use in 2007 than in 2006, use by Canada geese, tundra swans and diving ducks was lower in 2007.
Hunter Success Good in 2007
Some citizens were concerned that closed area changes would reduce hunter success.
However, hunter bag checks conducted opening day at boat landings between Wabasha and Winona, Minn. found that hunters averaged 1.6 ducks per hunter, as compared to 1.5 ducks per hunter over the previous 10 years.
In the La Crosse area, bag checks averaged of 1.2 birds per hunter in 2007, compared to 1.1 birds in 2006 and 1.5 in 2005.
A professional hunting guide reported 4.10 birds per hunter in 2007 compared to 3.08 birds in 2006. Another guide reported that in 12 years of guiding, his hunters had record harvests of seven different species of ducks in 2007.
Concern was also expressed that changes in closed areas would cause hunters to turn away. However, hunting pressure, measured by “car counts” at boat landings, was similar to previous years.
Opening day counts at 25 landings between Wabasha and Winona revealed 371 cars, very near the 10-year average of 381 vehicles. Car counts in the La Crosse, Wisc. area were also similar to previous years: 502 cars in 2007 compared to 530 in 2006 and 496 in 2005.
Public Compliance Was High
Waterfowl disturbance studies were made at eight closed areas. Observers, often perched on bluff tops over-looking the closed areas, noted boating activity and how waterfowl reacted to disturbance caused by boater intrusions.
Observer time was allocated to various mornings, evenings, weekends, weekdays, and holidays, October to December.
Nelson noted that, “Public compliance to voluntary avoidance and no motor provisions was quite good.” Observers reported no disturbance of the birds in some closed areas, including Spring Lake in Pool 5 and Kehough Slough in Pool 12.
Disturbance did occur at the Wisconsin River Delta Special Hunt Area, as noted in 56 hours of observation. In this case, 15 of 17 boating intrusions into the area caused minor bird disturbance. These boats were destined for a fishing hot-spot at the edge of the closed area.
A detailed study at the Wisconsin Islands closed area, in Pool 8 near Brownsville, Minn. indicated that boating disturbance levels were tolerable. In 267 hours of observations, researchers from the U.S. Geological Survey in La Crosse Wisc. documented 33 boating intrusions into the area. These intrusions caused an average of one major disturbance once every third day, less than the critical average of one every day, which would call for tighter restrictions in the future.
Observers were also stationed on bluffs above the Elk River closed area in Pool 13. Only three minor disturbance events were recorded in 51 hours of observation conducted during 11 days between October 6 and November 27, 2007.
Results of disturbance studies will be used to enhance public education about the needs of migrating waterfowl on the Refuge.
More details of bird use and disturbance studies are posted on the Refuge web site:
http://www.fws.gov/midwest/UpperMississippiRiver/
New updates will be posted as other reports become available.
The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service. For more information on our work and the people who make it happen, visit http://www.fws.gov
-FWS-
