November 09, 2009
GRAYLING, Mich. (MCT) - Sitting in a tree stand and watching a doe cavort with her twin fawns, I got to thinking about the DNA tests that some biologists did a few years ago in an effort to determine which age group of bucks did the most breeding.
The biologists were surprised to find that twin fawns have different fathers about 25 percent of the time. The twins were really half brothers and sisters because they grew from two eggs that had been impregnated by two males, often one older buck and one yearling.
Another research paper I read recently concerned a phenomenon that had puzzled deer biologists in parts of the South and that hunters were the first to observe the rut among whitetail bucks varied by as much as a month in regions that might be only 20 miles apart.
Since length of daylight is the primary factor in triggering the rut, that didn't make much sense. So Mississippi State and Texas A&M universities looked at the genetics of 13 closely associated deer populations in Louisiana and Mississippi and found surprising differences in their DNA.
The theory they have come up with is that hunt clubs brought in deer from a lot of other states in the middle decades of the 20th century in an effort to build up the local herds. Those imported deer had evolved different rut times over millennia to suit their home latitudes, and while you could move the deer out of a geographic area, it appeared that you couldn't take the geography out of the deer DNA, at least not in a human lifetime.
The doe I was watching browsed quietly on some goody she found on a bush, and as her fawns played a kind of deer tag, I wondered what more we'd learn about these remarkable animals now that we can apply levels of science to our study of them that our grandfathers couldn't.
We kill 70 percent of the buck deer in Michigan at the age of 1 ½. Is removing their DNA lines from the herd before most of them get a chance to breed hurting the deer population?
What does the DNA of a deer from St. Joseph County in southeastern Michigan look like compared with a deer from Crystal River in the western Upper Peninsula? Is that 400-mile, north-to-south spread between the two areas enough to make a significant difference in the start of the rut? October is noticeably warmer in 2008 than it was in 1978. Has this done anything to the timing of the rut? And if the computer models are right, and Michigan winters 40 or 50 years from now are like the present winters in Kentucky or Tennessee, what will it mean for a deer like ours that evolved in latitudes 10 degrees farther north?
We've learned a lot about deer, but I suspect the bulk of our knowledge about them is yet to come. Presumably, that increase in learning will result in good things for both the deer and the people who hunt them.
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