I personally believe their is no way to accurately figure out the ratio you have in your area unless you fence it up and start tranquilizing the deer. There isno way you can tell which deer move in and move out and how far their boundaries are. Especially with bucks, which might moves miles in one day.

Now granted, if you see 20 different does in one day, and no bucks, then i can see where you might be able to tell. But in my area, i could see 15 does one day in a stand and 5 bucks the next, it just depends on a bunch of different factors.

Now i can agree with what you said. After the fawns are born, if the ratio is very bad, then it should start to even out. You also have to account for the number of deer that get hit by cars. During the summer and spring months, i bet 80% of the deer i see hit are does. But then come fall and that number switches to the bucks.