Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

net flies over flock of ducks © Denis Winter

A cannon blast sends a net over hundreds of ducks dining on corn bait.
© Denis Winter

June 2012

Thirty years and nearly 35,000 ducks later

Banding at the Grand River Marsh Wildlife Area.

Jim Holzwart

I'm sitting in a blind surrounded by excited people as daylight seeps into the eastern horizon. We are waiting and watching the marsh come alive. Dark silhouettes seemingly appear out of nowhere.

Suddenly, the silence is interrupted by mallards gabbling and wood ducks whistling. I whisper to the group to watch until the band of yellow near the water's edge disappears. When it does, I reach over and ask the 12-year-old next to me to push the button.

Cannons ignite a thunderous roar and the blind becomes a flurry as wildlife management staff and volunteers rush to secure a net over hundreds of ducks.

The Department of Natural Resources has captured and banded waterfowl at the Grand River Marsh Wildlife Area intermittently since the 1960s and the Berlin wildlife management field staff has been running the show there since 1982.

The Grand River Marsh Wildlife Area, located in Marquette and Green Lake counties in central Wisconsin, officially came to be on February 21, 1958, when the Wisconsin Conservation Commission (forerunner to the Department of Natural Resources) acquired the property. Local sports clubs that supported converting the area into a wildlife refuge conceived of the project decades earlier.

Much has changed at the wildlife area since its founding, including a boundary expansion in the late 1990s to include more wetland habitat to the west.

What hasn't changed, though, is the importance of waterfowl banding at the marsh. The department gathered a lot of data over a four-year research project (1977-81), outlined in an excellent technical bulletin, Duck Breeding Ecology and Harvest Characteristics on Grand River Marsh Wildlife Area (Number 145), and produced by William Wheeler, Ronald Gatti and Gerald Bartelt.

But the need for banding data continued even after the research project ended. That's when local wildlife management staff stepped up. Tom Hansen (retired wildlife manager), Wayne Besaw (retired wildlife technician), Jim Radtke (retired wildlife technician) and Jerry Reetz (current wildlife technician) took over where the research staff left off.

While the basic capture method – using a cannon net over corn bait near the water – hasn't changed much through the years, several methods have changed and improved.

Originally, the netting site was a high spot next to open water. It was mowed to allow staff to place the corn bait and help the waterfowl feel secure coming up on shore (dense tall vegetation near a bait site can make birds wary of predators potentially lurking in the tall grass). But in wet years the birds were captured in very muddy conditions, so fill was hauled into the road and banding site to improve access and bird handling.

In the mid-1980s an elevated wooden blind allowed volunteers and department staff to observe birds as they came onto the bait. The blind provided an unobstructed view of the bait and made it easier for staff to determine when to launch the cannon net. Of course, on dense foggy mornings it's still difficult to see the bait and there have been a few times I've had to crawl into soaking wet grass with a radio in hand to get close enough to see the bait and give the "green light" for firing the net.

Over time, the blind and wooden ladder needed repairs and eventually the blind needed to be replaced. Jerry Reetz, the same Reetz who was there at the beginning, found an old metal staircase that was being removed from a second story apartment building in Berlin. The staircase was a perfect replacement for the wooden ladder. Reetz acquired the staircase for free and all we needed to do was pick it up. Several weeks later the staircase was dismantled, modified for height, repainted, put back together and ready for Grand River.

Through a gift from the Northeast Wisconsin Chapter of Safari Club International we also designed, purchased materials and constructed an elevated aluminum blind with sides, a roof and stadium seating big enough for eight people. Many bags of cement and large metal supports later, the staircase and blind were in place and sturdy enough to support a herd of excited duck banding helpers.

The new blind gives an outstanding view of the bait site and the marsh without fears of falling out or disturbing the birds.

Other major modifications included increasing the capture net size and adding additional cannons to propel the larger net. The capture net is 40 feet wide by 80 feet long and launched by five "cannons." Each cannon is a large metal weight attached to the net and slides over a solid metal pipe anchored in the ground. A standard 12-gauge shotgun shell loaded with 170 grains of black powder equipped with an electric match to detonate it is inserted into a hole at the end of the pipe.

The explosion provides enough energy to propel the weight of the net over the ducks. Each cannon trajectory and elevation is adjusted so the weights and net fly over the top of the birds, but low enough so they cannot escape from under the net. Each cannon charge is connected to a junction box connected to the elevated blind about 100 yards away.

Why band waterfowl?

Besides the lure of big pancakes at a local restaurant (Did I mention we buy breakfast for our volunteers?), bird banding is critical to North American migratory bird management.

Photo of hand holding duck with band on foot. © DNR File Photo
Banding is critical to studying migrating waterfowl in the United States.
© DNR File Photo

According to the North American Bird Banding Program, "Bird banding is important for studying the movement, survival and behavior of birds. Data from banded birds are used in monitoring populations, setting hunting regulations, restoring endangered species, studying effects of environmental contaminants and addressing such issues as Lyme disease, bird hazards at airports and crop depredations. Results from banding studies support national and international bird conservation programs such as Partners in Flight, the North American Waterfowl Management Plan and Wetlands for the Americas. About 58 million birds representing hundreds of species have been banded in North America since 1904. Over 3.1 million bands have been recovered and reported."

Wisconsin is considered an important component in the strategy because it is a "breeding state" for major waterfowl species.

"The Wisconsin Department of Natural Resources works with its Mississippi Flyway partners to identify banding needs, plan strategies and coordinate waterfowl banding operations," says Kent Van Horn, DNR's migratory game bird ecologist. "Our efforts are part of a larger picture and because Wisconsin is a breeding waterfowl state, our banding accomplishments are important to the continental management of mallards, wood ducks and Canada geese."

Banding data give the department and the U.S. Fish and Wildlife Service (the ultimate decision makers for all migratory bird species) the ability to evaluate harvest impacts on hunted species. Take mallards as an example. They are our targeted species at Grand River. We have been able to calculate a 56 percent survival rate from the banding recoveries for 2000-2007.

This is lower than the 60 percent survival rate in most other regions on the continent and supports the continued emphasis on a more conservative hen mallard harvest (one hen mallard bag limit) so as to not impact local mallard reproduction.

That's a lot of banded ducks!

Larry Vine, retired DNR researcher from Horicon and keeper of the Wisconsin duck banding information for many years, summarized banding recovery records from the early 1960s until 1998. Vine tapped into the database maintained by the U.S. Fish and Wildlife Service Bird Banding Lab in Laurel, Md., to determine recovery rates and locations for 23,281 mallards captured at and near Grand River.

A total of 2,149 recovered ducks (9.2 percent of the total banded) were shot in the same year of banding. When Vine looked at the percent of birds harvested in Wisconsin that came from Wisconsin it ranged from 63.4 percent to 68.93 percent, depending on the age of the captured mallard. It supported the thinking that most ducks harvested in Wisconsin, come from Wisconsin.

This may seem like a small number of band recoveries, but if you consider the number of mallards out there – about 187,000 Wisconsin birds in spring and 9.2 million birds continent-wide in fall of 2011 – it's not surprising that few of the harvested birds are banded. Nonetheless, that's enough recoveries to draw some conclusions on survival and movement.

So, just what are people catching and banding at Grand River and how many over the last 30 years? For the number lovers: 31,119 mallards (8,826 adults, 22,293 immatures), 591 wood ducks, 491 pintails, 134 black ducks, 12 Canada geese, five green-winged teal, two identified as hybrids (mixed genetic background), and one blue-winged teal were banded at Grand River since 1982.

The total is 34,966, not 35,000, but that is still a lot of banded ducks!

Report bird bands

Hunters, report bird bands to the Bird Banding Laboratory by visiting Report an Encounter of a Marked Bird or by calling 1 (800) 327-BAND (2263). If you report a band online, you'll receive an electronic certificate explaining where and when the bird was banded, the sex of the bird, and the person and/or agency that banded the bird.

For me, one of the most interesting aspects of waterfowl management is where these birds travel. Banding data provide insight. Some of the earliest information from waterfowl banding helped us identify four flyways: the Pacific, Central, Mississippi and Atlantic. We also created separate areas for management and regulation.

The long history of banding, and many recoveries from birds banded at Grand River, gives us a good understanding of where these birds end up. As you might expect, many of the banded birds end up harvested or recaptured at Grand River.

The large-scale research project of the late 70s and early 80s showed birds moving locally between some of the larger Wisconsin wetland areas prior to the fall hunting season. Mallards captured and banded at Grand River were recaptured at Collins Marsh (Manitowoc County), Eldorado Marsh (Fond du Lac County), Mead Wildlife Area (Wood and Marathon counties), Horicon (Dodge County) and Necedah (Juneau County) national wildlife refuges.

Even though the majority of Wisconsin mallards are recovered in the state, they travel all over North America. We have birds recovered from Alberta to Alabama, from Washington to West Virginia and about every place in between. The idea that a bird in my hands may end up in Saskatchewan is mind-blowing. Wildlife never ceases to amaze me!

What does this mean for you?

Most of this data collection would not be possible without the volunteers who help with our banding effort every year. Can you think of a better time than getting up hours before sunrise, climbing into a darkened blind, waiting to see a huge billow of smoke so you can crawl around on the wet ground and grab squirming, scratching, desperately-trying-to-escape ducks? I can't. And don't forget the pancakes!

If this sounds like fun, please contact me at the Berlin Wildlife Field Station or talk to your local DNR wildlife biologist (if they do not band ducks locally they will know who does) to find how you can help.

The department bands statewide and is looking for help. Normally, we band in early August into early September, and at Grand River we look for about six to eight volunteers per attempt.

We try to schedule one or two bandings prior to school to get as many kids out as possible, but all ages are welcome. Bring waterproof shoes or boots, rain pants, long-sleeve dark or camouflage coat or jacket and a big appetite (the pancakes are huge).

As I write this, I can still picture myself sitting in my banding chair watching the kids wrestling the ducks out of the net and happily carrying them over to me to be banded. You won't forget the experience and the expressions on volunteer faces when the birds take flight after release.

Jim Holzwart is a wildlife biologist at the Berlin Wildlife Field Station in Green Lake County. To reach him, call (920) 361-3149 or email Jim Holzwart