Mature bucks are just generally less predictable than younger ones.
Although should you have years of studying a particular buck, you may be able to predict his future actions better than a particular younger one. With exception to large public hunting tracts, most TN hunters don't have enough acreage to encompass most bucks' lifetime range shifting.
However, mature bucks often utilize less acreage at maturity, sometimes spending a year apparently never leaving an area as small as 100 acres (or less). Unless you disturb them too much, then they "move over" to some other 100 acres.
They are also more wary, and in many respects, their behavior can be so very different from a 2 1/2 or 3 1/2 that you can think of the mature buck as a different species of animal.
While they are more likely to be mostly nocturnal, they are also more likely to be moving in mid-day.
Go figure.
They also have a tendency to follow (often at a considerable distance) younger bucks, and am not talking about "young" bucks, but more the case of a 5 1/2-yr-old trailing a 4 1/2-yr-old. They may be so far apart each appears a "loner", but the more mature one is using the younger one to be first in checking for any danger.
Another tendency is to parallel trails more than walking on the more established trails. You may have a parade of deer, including 2 1/2 & 3 1/2 yr old bucks come by. Later, the mature one RUNS by, parallel to the others (typically downwind of the trail).
Which brings up another trait:
They have more a tendency to run from Point A to Point B,
as opposed to simply slipping along a trail.
The mature one may stand motionless for a long period as the other deer mosey along. Then suddenly, he just takes off in a flat out run, only to stop again, and stand for a long period.
Making them even more unpredictable, they are more likely to "cut a diagonal", and do so in a flat out run.
They may be following along behind other deer, off-set to the other deer's trail by 75 yds, perhaps 150 yds behind them, but the deer they're "following" are on a trail that twists & curves. Next thing you know, the mature buck takes a "short cut" by "cutting the diagonal", maybe only needing to periodically "run" 150 yds for every 250 yds the other deer are more steadily just mosying along.
