Paul Meisenheimer
Well-known member
I know a retired waterfowl biologist and during a recent discussion about Canvasback and Redhead bag limits I asked a related question about the current Ontario daily bag limit of one American Black Duck. I thought I would post my question and his answer here and see what kind of response it gets. I will also ask this group the additional question: given the minimal impact of hunters on the Ontario population of the American Black Duck is the current bag limit of one justified?
question: I often wonder about the effectiveness of the 1 bird limit for black ducks. So many birds harvested are showing signs of being blackXmallard hybrids that I also wonder about the long term prospects. I really don't know much about the issue and simply am curious. Any thoughts?
answer: I have lots of thoughts on the effectiveness of the 1 Black Duck limit in southern ON, which was brought in to reduce harvest of Black Ducks in an attempt to stop their continued decline. As it happens, I spent a fair amount of my research career studying the relation between Mallards and Black Ducks ( you can see a list of published papers here: http://scholar.google.ca/scholar?q=ankney%2C+black+ducks&hl=en&btnG=Search&as_sdt=2001&as_sdtp=on )
In summary, here's what this research showed:
1) M's and BD's are extremely close genetically -- BD's are more similar to M's than are some M populations to other M populations;
2) M males are dominant to BD males and if courted by a male M and a male BD, a female BD almost always ends of choosing the M;
3)M's outcompete BD's for nesting areas and as a result M's have replaced BD's on all all but the least fertile, least productive habitats in ON and PQ;
4) Hybridization with M's and "competitive exclusion" by M's has caused the long-term decline of BD's in Canada and harvest has had nothing to do with the decline.
Since my research was done, M's have spread farther east and have now displaced BD's from the most productive areas of NB, e.g., St. John's River valley and have moved in to NF and are increasing there.
Bottom line is that the 1 BD limit has done NOTHING to stop the decline of BD's because it's M's, not harvest, that are causing the decline. Your Grandkids will be just as thrilled to shoot a Black Duck in ON 50 years from now as your Grandfather was to shoot a Mallard in ON 50 years ago.
question: I often wonder about the effectiveness of the 1 bird limit for black ducks. So many birds harvested are showing signs of being blackXmallard hybrids that I also wonder about the long term prospects. I really don't know much about the issue and simply am curious. Any thoughts?
answer: I have lots of thoughts on the effectiveness of the 1 Black Duck limit in southern ON, which was brought in to reduce harvest of Black Ducks in an attempt to stop their continued decline. As it happens, I spent a fair amount of my research career studying the relation between Mallards and Black Ducks ( you can see a list of published papers here: http://scholar.google.ca/scholar?q=ankney%2C+black+ducks&hl=en&btnG=Search&as_sdt=2001&as_sdtp=on )
In summary, here's what this research showed:
1) M's and BD's are extremely close genetically -- BD's are more similar to M's than are some M populations to other M populations;
2) M males are dominant to BD males and if courted by a male M and a male BD, a female BD almost always ends of choosing the M;
3)M's outcompete BD's for nesting areas and as a result M's have replaced BD's on all all but the least fertile, least productive habitats in ON and PQ;
4) Hybridization with M's and "competitive exclusion" by M's has caused the long-term decline of BD's in Canada and harvest has had nothing to do with the decline.
Since my research was done, M's have spread farther east and have now displaced BD's from the most productive areas of NB, e.g., St. John's River valley and have moved in to NF and are increasing there.
Bottom line is that the 1 BD limit has done NOTHING to stop the decline of BD's because it's M's, not harvest, that are causing the decline. Your Grandkids will be just as thrilled to shoot a Black Duck in ON 50 years from now as your Grandfather was to shoot a Mallard in ON 50 years ago.