Posted: 12/8/04
A successful swan song
And scientists are working hard to keep it that way
 This was the view in Raft Channel West, five miles south of Brownsville, on November 30. This area contained about 6,000 swans that day. The swans are still on the river. They leave in mid- to late December for a non-stop flight to the East Coast. Photos by David Heiller |
By David Heiller
Argus News Editor
We sat in our car in front of Heiller Valley last Tuesday and gazed with wonder at the river.
ìLook at the birds,î Jim Nissen said. ìWow. Look at the birds.î
Now these words of awe were not coming from your average tourist. Nissen is the district manager of the Upper Mississippi National Wildlife and Fish Refuge.
But thousands of tundra swans will make even a grizzled veteran like Nissen in awe.
It was an impressive sight, all those white birds caught against the dark blue water in the fading sunlight of a late fall day.
And the sound was equally wonderful, a huge and slightly eerie chorus of honks and clucks that are almost human.
Kevin Kenow, a coworker of Nissen, sat in the back seat. He works for the U.S. Geological Service Upper Midwest Environmental Science Center.
I asked how many swans we were looking at.
Nissen took only a few seconds before answering, ìIíd say somewhere around 4,000 plus.î
Kenow scanned the river for about a minute. ìIíd say 6,000 in the good ballpark,î he said.
ìA lot of ducks too,î Nissen added.
Kenow had been at the site the night before with a night vision scope. He had counted only 500 swans then.
Swans are smart, he explained. At night they leave the areas that are closed to hunting and go to open-hunting areas. Thatís because there is less human activity in the open areas at night. (There is no tundra swan hunting season in Minnesota or Wisconsin, although there has been discussion to open it up to limited hunting.)
Jim and Kevin pointed out different swan behavior. Some were ìtreadling,î that is moving their feet like your grandmother worked her old treadle sewing machine. They do that to dislodge tubers to eat.
The bay in front of Heiller Valley, or as Nissen used to call it, the Highway 26 Peninsula, is full of tubers from arrowhead plants and sago pondweed. And hence it is full of swans as they migrate from the Hudson Bay area to the eastern seaboard.
Jim said sometimes you can see the tubers go down their long throats. Kevin passed me his binoculars ñ a very fine pair of binoculars ñ and told me to watch an adult pair and their one young offspring. I did, and sure enough, I could see a big bulge go down one of the birdís throat.
We left the spot, five miles south of Brownsville on Highway 26, and drove north. Swans were scattered all over the river like popcorn. Those 6,000 birds we had seen were just a fraction of the number that we took in as we headed north to Shellhorn. From there on they moved further out by Horseshoe Island.
It was a calm day, Nissen said, so the birds were all over western part of the river up to the main channel a mile to the east. Many were loafing, he said. ìTheir feet are firmly planted.î On a windy day they would seek protection in sheltered spots.
A scientific approach
Nissen and Kenow are part of team that is helping make that happen, and their arsenal of tools and knowledge is enough to make your head spin. At least it did for me as they shared their work and knowledge for two hours.
Take that spot in front of Heiller Valley. (I fondly call it that in honor of my grandma, Edna Heiller, and my uncle, Donny, who took over the farm before he and Grandma sold it to the State of Minnesota in 1967.)
Kevin and three co-workers are intensely studying the spot. They are doing ìtime-activity budgetsî there in a large area that has been staked off.
Workers record the behavior of a good number of the birds, using a spotting scope mounted in the window of their car. A timer goes off every five seconds, then workers record activities like feeding, tipping up, preening, swimming, chasing, and treadling. They use the information to get an idea of what the total flock is doing.
Also in the spot, Kenowís crew has staked several wire barriers in place. (A total of 120 barriers were placed in three beds in Pool 8.) Swans cannot get to the tubers under the barriers. In the spring, Kenow and his crew will take core samples from beneath the barriers and compare them with areas where the swans were feeding. They will check the areas again in the summer to see density of growth.
All of this information will help the researchers measure the impact of swan feeding and the viability of their beds. Their work started in 2003, and is considered a priority research need.
The workers get high-tech help too. They use digital aerial photography to determine daytime distribution of birds, and thermal infrared images to see where the birds go at night to feed and rest. These images are run through a computer program to give a very accurate count of the numbers of birds.
All of this information is used to develop ways to help the swan terrain.
Some big changes will be coming to Raft Channel West in the coming years. Several islands will be built starting next year if funding is granted. The area south of Shellhorn will have a much different look, with more islands and stands of rushes. The islands will help the swans by providing loafing habitat on windy days, Nissen said.
A lot of potatoes
Nissen and Kenow prefaced our visit to the river with an interview at the Copper Penny in Brownsville.
Food reserves get depleted in the closed areas in late November, Nissen said. He pointed to a sheet that stated a swan needs to eat 64-92 tubers a day for its food energy requirements ìThatís a heck of a pile of potatoes,î he said. ìYou canít go to McDonalds. Youíve got to get it here.î
A lot of birds in Raft Channel West are moving to the Onalaska area now.
Nissen said the drawdown in Pool 8 in 2001 and 2002 brought a big change in the pattern of swan use. ìThey didnít need to range out as far as they did.î
There will be a drawdown in Pool 5 next year, in the hopes of spreading the swan population our so a catastrophe doesnít impact them so severely.
Nissen said he and his wife, Ruth, had taken a drive down the river a week earlier and had rough-counted 12,000-15,000 birds.
As we were leaving the Copper Penny (after I ate a delicious bowl of soup), Nissen asked owners Lana Twite and Pat Sanders if they had seen an increase in business from people who were looking at swans. Twite said yes, on nice days.
Her statement corroborated what Nissen had told me earlier, that the swans were providing enjoyment for many people.
That includes novices like me, and experts like Kevin Kenow and Jim Nissen.
ìI like watching waterfowl, yes,î Nissen told me. ìThatís why weíre in the business. We enjoy them.î
A ëglobally importantí areaóand a whole lot of swans
The Mississippi River in Pool 8 between Dresbach and Genoa is part of a 260 mile area that was declared ìglobally importantî to migratory birds by the American Bird Conservancy in 1997.
It is part of the groupís Important Bird Area program.
The area provides critical support to bald eagles, the Eastern Population of tundra swans, and canvasback ducks.
At their peak in late November, about 31,000 tundra swans, or 25 percent of the Eastern Population funnel through the area. Those numbers are a 700 percent increase from the early 1980s.
The swans migrate here starting in the fall from the northeastern shore of Hudson Bay and Baffin Island, passing through the prairie provinces of Canada and the Dakotas.
They stop here to fatten up on the leaves, stems, and tubers of aquatic plants like arrowhead, wild celery, and sago pondweed. An adult swan consumes about six pounds of tubers a day. Local wildlife managers have put a high priority on studying what impact the large swan numbers are having on the tuber supply.
Swans stay here until the river ices up, usually in mid- to late December. They then proceed to the Chesapeake Bay area on the Atlantic coast, from New Jersey to South Carolina. They fly non-stop, and with a good tailwind, they are able to make that journey in about a day. I asked river worker Jim Nissen how that was possible. ìThey donít have to go through Chicago,î he said with a smile as we visited at the Copper Penny on November 30.
Not only is it a straight shot, the swans wouldnít have many places to stop if they wanted to. ìThereís not much left,î Nissen said, and this time he wasnít smiling.
The canvasbacks split, some going to the Gulf Coast and some to the East Coast.
More than 70 pairs of bald eagles nest in the area, with more than 600 eagles wintering in the Upper Mississippi River and Trempeleau National Wildlife Refuges. The refuges also contain more than 260 other species of birds.
The fall swan population has shifted from areas further north to our area. Thatís because the submersed aquatic and emergent vegetation there suffered a severe and inexplicable decline. Combine that with exceptional tuber production in Pool 8 in 2001 and 2002 and you have swan heaven, right at our doorstep.
Swans also pass through our area in the spring on their way north, but their stay is brief as they continually move north.
Tundra swans weigh between 12-20 pounds, are about three feet tall, and have a wingspan of 6-7 feet.
Canvasbacks and eagles too
There are also many canvasback ducks and eagles in the Upper Mississippi River and Trempealeau National Wildlife Refuges.
Pools 7-9 are also a main staging area for fall canvasbacks, due to the good wild celery crop. From aerial surveys, the peak canvasback population recorded on the entire Refuge in 2004 was 245,230 the first week of November, Nissen said.
In spring 2004, the estimated canvasback breeding population within the area surveyed was 617,000. Thatís about 25 percent of the worldís population.
About 21,000 canvasbacks were counted in the Wisconsin Islands Closed Area, the areasouth of Brownsville, on November 29.
According to Refuge Biologist Eric Nelson, in 2004 there were 136 nesting pairs of bald eagles on the Refuge and they produced 186 young. Wintering numbers approach 1000 birds.
More mallards have also been seen too, Nissen added.
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