 |
 |
From the October 1998 issue:
|
Home-grown harvestMany of the "northern" ducks we watch or hunt each fall are raised right here.RON GATTI and JON BERGQUIST |
People often question where our wild ducks come from, and of course there's a simple biological answer - eggs! But those people are really asking whether the ducks hunted here and the ducks we see migrating through in spring and fall are "resident" ducks that were born and bred in Wisconsin, or are "migrants" that pass through Wisconsin on their way to breeding grounds in Canada.
Answering that question has implications for the management steps we use to maintain healthy flocks. First, it would help to know where the majority of ducks harvested during a given period of time were hatched. For example, if we harvest mallards and mainly hatch in the Canadian prairie country, we might be able to offer grater hunting opportunities than if the majority of those birds were hatched here. Similarly, if mallard reproduction is very low in the prairie country (as it was in the late 1980s), we might not need to cut back as much on our harvests here if our birds were raised in-state.
On the other hand, if most of our ducks are locally-raised, then we might be overharvesting when we offer liberal seasons as we did in 1997 and 1998. So it's very important to know where the ducks that we hunt are raised.
Likewise, it is important to know if the sources of ducks available to hunters change during the fall season. For example, if needed, we might protect local breeding mallards by restricting the bag limits early in the season and allowing normal bag limits later if we knew that was necessary. It would help to know if we need to reduce the harvest of local mallards or if these birds are available all fall and are harvested at t he same rate from early October through November.
Migration rates and harvest information also help us determine where to spend your dollars to enhance duck production. Currently about a third of the money we receive from the state share of the federal waterfowl stamp must go for habitat improvements in Canada. We want to ensure that those dollars are present were they will provide the greatest benefit to state residents. So we decided to review past research reports and do some additional studies.
To determine what proportions of the "northern" ducks come from Canada and from the United States, we study ducks' leg bands. Biologists annually capture a small sample of ducks in the summer and place small metal bands imprinted with coded information around one of their legs. The bands in no way interfere with the birds' survival. When researchers recapture these ducks in subsequent surveys or when hunters bag such ducks, we ask them to report the band information to the U.S. Fish and Wildlife Service. Past studies indicate only a third of the banded birds hunters bag are reported, and better accounting could greatly improve how we manage duck populations. To make reporting as convenient as possible, hunters can mail in the bands to the address provided or call a toll-free number (1-800-327-2263) which is staffed 8 a.m. to 4:30 p.m. Monday to Friday, with automated answering services on evenings and weekends.
Information from past U.S. Fish and Wildlife studies creates a picture of ducks typically hunted in Wisconsin as shown in this table.
In past studies, the U.S. Fish and Wildlife Service summarized results for duck bands turned in following the hunting seasons from 1961-75. Those studies estimated 55 percent of the mallards harvested in Wisconsin come from the so-called Lake State Region of eastern Minnesota, Wisconsin, Michigan and northern Illinois. (Banding Reference Area 14). Nearly 19 percent of the mallards harvested in those years came from the evergreen forests of northern Ontario, northern Manitoba and northern Saskatchewan (Banding Reference area 7). A nearly equal amount (21 percent) came from the 