I have a heard a lot of people discussing the decline in red-breasted merganser numbers over the years.  One of the most amazing sights I have ever had a chance to witness was watching approximately 250,000 red-breasted mergansers pass by the Vermilion area.  The following year ODOW surveys confirmed close to that number.  It was stated that the majority of the red-breasted merganser population was using Lake Erie as a staging area.  What happened?

 

Those sightings were during the 1980's.  Since that time it seems that there has been a steady decline in red-breasted merganser numbers on Lake Erie.  In the early 1990's I remember seeing flocks that probably exceeded 100,000 birds.  November was the best time to see this and the Huron-Vermilion area was the best location.  Last weekend I was at Huron and didn't see a single red-breasted merganser.  There are decent flocks around especially east of Cleveland, but most of these flocks are 5,000 or less.  Where are the bigger flocks?

 

Should we be concerned with this decline.  Are the red-breasted merganser flocks spreading out over the Great Lakes, are they passing us by, or is there a major decline?  As far as waterfowl surveys go, they seem to lump all of the mergansers since thay are not as important to hunters.  Vic Fazio had numbers of Ohio red-breasted mergansers through the years.  Hopefully he is out there and can post them.  There appears to be something going on here.  Were the 1980's unusual that for some reason there was a massive increase in mergansers.  Maybe there is something to this.  If you go to the Christmas Bird Count website and create a graph for red-breasted merganser, from 1960- present for the United States, there is a large spike in numbers from about 1982-1993  Before and after the spike, the graph is pretty level.  Interestingly, if you create a graph back to the 1930's, there was a shorter spike from approximately 1937-1942.  Maybe the question should be, what caused the spike in numbers in the 1940's and 1980's.  Also how do the last few years numbers locally compare with numbers in the past outside of the peeks.  The Christmas Bird Count data is limited in use for Ohio since most of the mergansers have departed by the time of the counts.  Although data shows there has been an increase over the last few years in Ohio.  

 

If you want to play with the Christmas count graphs, here is the link.

 

http://audubon2.org/cbchist/graph.html

 

John Pogacnik
                                          
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