Beginning in the autumn of 2012 the Great Lakes Commission began a collaborative project to document bird distribution in the offshore waters of the Great Lakes. One of the ultimate goals of this project was to use the bird distribution data collected to help inform wind energy developers about important bird areas and consequently help mitigate the negative impacts of wind farms on birds that use the open waters of the Great Lakes. Data is collected for this project via aerial surveys, and I am part of a team of observers that makes weekly flights over Lake St. Clair, the Detroit River, and western Lake Erie recording and mapping bird locations.
Lake St. Clair lies between lakes Huron and Erie connecting to the two through the St. Clair and Detroit Rivers, and even though it measures close to 24 mile across at its widest point it’s rarely included as a member of the Great Lakes. Despite its small stature in comparison to Superior or even Erie, Lake St. Clair is an incredibly productive fishery and one of the most important migration staging areas for ducks, geese, and swans in North America. Because Lake St. Clair encompasses over 400 square miles of open water but rarely exceeds 20 feet in depth the entire lake is capable of supporting aquatic plants that provide the habitat and food resources necessary to support strong populations of smallmouth bass, walleye, and muskie and hundreds of thousands of waterfowl every fall and spring.
|Picture taken during our winter aerial survey work over Lake St. Clair that contains over 1700 canvasbacks.|
On any given survey it’s not unusual for us to see a host of different bird species including bald eagles, northern harriers, common loons, tundra swans, coot, and any number of different dabbling duck species; however, if one is looking for a headliner, diving ducks certainly steal the show. Canvasback, scaup, and redheads are all members of a guild of ducks collectively referred to as diving ducks because they often feed by diving underwater to eat aquatic plants or small invertebrates and all three species stage in staggering numbers on Lake St. Clair during October and November. Our peak estimates of all diving ducks on Lake St. Clair and western Lake Erie have exceeded over a half a million ducks during peak fall migration! To put this in perspective, on one particular survey we counted 262,200 canvasbacks. The entire population of canvasbacks as estimated by the U.S. Fish and Wildlife Service in the spring of 2012 was 759,900 meaning that approximately 36% of the entire population of canvasbacks was on Lake St. Clair on that one, single day. Furthermore, we have encountered a flock of diving ducks that covered approximately 12 square miles of water and through a series of photos we estimated that group to contain at least 350,000 ducks.
|Picture taken during our winter aerial survey work on Lake St. Clair that includes canvasbacks, scaup, and redheads. Notice the muddy water that is likely an indication these birds were feeding prior to being alerted to the presence of the airplane.|
Perhaps the most intriguing aspect of Lake St. Clair isn’t just that it supports booming fish populations and hundreds of thousands of birds, but that it does all this while at the same time being in millions of people’s backyards seeing as it’s only a hop, skip, and a jump from Detroit, Michigan. This proximity to people is a bit of double edged sword because Lake St. Clair offers a tremendous number of folks an opportunity to hunt, fish, and appreciate Michigan’s natural resources, but ultimately it’s this proximity to such a heavily altered and developed landscape that causes a multitude of problems for the lake. Negative impacts from invasive species, decreased water quality, and shoreline development can all be observed on Lake St. Clair, and although wind energy is largely perceived as green energy, without careful planning offshore wind turbines could have significant impacts on waterfowl and other waterbirds. Although most research suggests mortality caused by collisions between waterfowl and wind turbines is minimal, it is likely large wind farms will exclude ducks from using large portions of the lake as they tend to give these turbines a wide berth. This being said, it will be critical for wind energy developers to avoid areas of the lake that are important feeding and loafing areas for the birds and corridors that help connect these areas if Lake St. Clair is to continue as an area of continental significance to waterfowl. The thought of depriving my child or your child of the opportunity to see 10,000 canvasbacks fill the western sky as they arrive on Lake St. Clair fresh off their travels from the windswept prairies of Canada is not a thought I am comfortable with.
|Canvasbacks and scaup in flight observed during our second survey of this spring over Lake St. Clair.|
Special thanks to my fellow observers Howie Singer, Ryan Boyer, and Dave Luukkonen as well as Northwoods Aviation’s Derek DeRuiter. Without these people none of this work would have been possible.
Michigan State University