I have a hunch after hunting them for a while.

Few predators in the Midwest other than man. (pretty obvious)
Being involved with insurance for 12 yrs., LOTS killed by autos.
Winter Kill-off is extremely minimal here
Disease? Not oftenother than some cases of CWD

Does will run off the Button Bucks sometimes very early. I would say there mortality rate is very high.

I would not doubt as a 1.5 yr old buck, being pretty doped up on test. if the number is not around that. They are pretty stupid and folks shoot them.

Isee every year1.5 yr olds hanging out together, sparring, clicking horns,all through the season ina relatively small area. They should be safe from natural predators and they seem to get along. But the 2.5 and 3.5 will freakin thrash them when a doe is in heat. Seen that also. Watched one about kill a little buck down in the water in a ditch.

I would say the following year is when they will get with it fighting. 2.5 to 3.5 yr old. And a lot of folks find some locked up dead. Think about how many hunters find shot from the previous season. A bunch.

And as you knowwhen they get 4.5 yr old they are a totally different creatures. I believe they do not fight as much when they get older but know how to lay back and just be patient and wait forgo-time. Let the young guys find the gals and then go take them awayand lock down.

Nothing new here but just fun discussing and from observations.edit: I am not an expert. But I do shoot 2" groupsat 60 yds all the time.