Loons Living on the Edge of the Water Need Our Help

By Ross Powers-Michigan Loon Preservation Association, Michigan Audubon Society

With the removal of some 300 dams by the State of Michigan, we expect that the ecology in these areas will change for many animals and birds, especially loons.  These birds depend on woodland lakes and ponds for nesting, food, and shelter.  Loons are not able to adapt to drastically changing water levels, as many other lake inhabitants can. Recently, the Michigan Loon Preservation Association (MLPA) has been involved in providing information to concerned citizens interested in saving loons from the effects of extreme water level changes from impoundments that will be drained by the removal of dams.  Sudden changes in lake depths, reservoirs, and ponds can have dire consequences on the populations of the Michigan threatened species: Gavia immer, the Common Loon.

Loons can tolerate some natural water level fluctuations, but they are intolerant of rapid changes. Because water level fluctuations can inadvertently eliminate loons from traditional waters, citizens need to be aware of what happens before flooding, draw downs, or draining of reservoirs.  If we are involved soon enough, the MLPA, Loonwatch, and Loon Rangers can help minimize the impact on loons.  We have historical data on loon lakes, nest sites, and breeding seasons that can aid.  We also know of mitigating measures which can encourage loons to select other nearby lakes, so that removal of dams and water level changes can proceed with less of an impact on this threatened species.

What makes the Common Loon so sensitive to water level changes?  The Common Loon has evolved over eons into a very specialized bird.  But such specialization often works against the loon in rapidly changing times.  A sudden decrease in water levels can actually reduce the area of a lake and make take-off from the lake more difficult.  Take-off appears to be a cumbersome process as they begin to take off by running forward  while flapping their wings and pushing against the of the water with their feet. This may require a one-quarter mile runway or involve several circles around the lake.  A loon’s legs and feet are ideally suited for propelling them through water, but not at all functional for walking on land.  Loons have solid bones that allow them to dive in order to catch their preferred prey, small fish. 

 A loon’s lake is its home, and after years of careful selection, it is traumatic for them to find their lake diminished or dry.  Once a loon pair picks a lake, the size, depth, and shoreline configuration must remain almost the same.  Loons return year after year to their ideal lake, usually to the same nest site.  They defend this territory from others that would like to make it their lake. They build their nests close to the shoreline, literally living on the edge.  If the water level drops, they often give up the nest site.  Besides being the right size, depth, and shoreline type, loons select lakes with lots of fish to eat, and islands of cattails and bulrushes to nest on.  Loons appreciate a little privacy, such as lakes without many cottages, and lots of space around their nest site.  The loon chicks leave the nest for nearby water right after they hatch and really never venture back onto land until they are of breeding age in 3 or 4 years.  Then they mate, make nests on shore, and risk being caught out of their element by predators. Some lucky loons build their nests on natural islands or floating bog mats. Not all lakes have ideal sites, and some nests are built on low-lying areas on shore.  Speeding watercraft can wipe out these nests with just a few large waves. Every egg is precious when there are only one or two eggs each year.  Loons spend their life in the water except during nesting and when they are dying. 

Now that you are aware of the limitations of loons, you can make a difference.  Join our Loonwatch program, or give a friend a membership in the MLPA so they too can enjoy protecting these challenged birds.  If you know of a situation where a loon’s lake is being artificially flooded or drained, please alert Michigan Loonwatch State Coordinator- Joanne Williams: 989-828-6019  or The Michigan Loon Preservation Association - Arlene Westhoven: 231-599-3132 or 231-796-6153, so we can provide the loons with nesting alternatives.