There's a lot of variable here. What exactly is mature? Well, its different to each person. To some people a deer might not be "mature" until he is what other people would call an old deer. To others as soon as he isn't a two point he's mature. I personally define a mature deer as a 4.5 year old deer. That's when he has stepped over from being a "teenager" to a "man" that can run his own harem. They really start to act different at this age. By 4.5 a deer will tend to start to have a rack that is close to his biggest, or at least closely resembles his biggest. He will still get bigger as long as the winter conditions and feed are right, but not usually the exponential jumps you've seen up to that age. A 4.5 year old deer is definitely in his prime as far as surviving winters goes and you find very few of this age class dead compared to younger and older bucks.
There's nothing wrong with defining maturity at other ages or landmarks, but each person has a different idea of what a "mature" deer is to them. That is just mine.
>I've always had the opinion that
>muley bucks aren't fully mature
>until at least 6-7 years
>of age. As a
>general rule, as long as
>a muley buck's body size,
>antler base (pedicles), antler main
>beams continue to grow... antler
>size continues to increase.
>
>There has been more studies conducted
>on whitetails than any antlered
>deer. Muledeer may not
>be exact but I'm sure
>a lot of the same
>things hold true. Here's
>a few interesting articles on
>antler growth and age:
>
>
https://www.qdma.com/antler-growth-bell-curve/
>
https://www.qdma.com/can-estimate-bucks-age-shed-antler/
>
>
https://www.gohunt.com/read/life/the-key-to-antler-growth-age-genetics-nutrition#gs.jwzz0t
>
>One thing that is consistent through
>just about every article I've
>read is that most buck's
>continue to grow in body
>size and antlers past 5
>years of age. Also,
>things can change from 1
>location...and 1 year to the
>next depending upon age, genetics,
>nutrition, weather, etc.
Studies on whitetails can be useful when talking about mule deer, but the differences between the species don't allow an apples to apples comparison.
For example, whitetails do not have the same type of winter struggles that most western mule deer face. They don't have to migrate to survive. A whitetail's food source tends to contain more of the things they need to survive year round (nutrition) and be more plentiful. Whitetails are all around just more adaptable to their environment than muleys and thus why they can live just about anywhere. These things lead to the fact that your average western mule deer does not live as long as your average whitetail. Like most species, a shorter lifespan usually means a quicker maturation.
Of course different locations would change this as well. In Arizona, mule deer don't have to worry about winter as much or migration (at least not the to the extent of mule deer in the mountain west), but they are even more dependent on moisture and availability of nutritious feed for body and antler growth. Arizona can have a whole different effect on a deer obviously though as can be seen by the whitetails that thrive there. Everything's just a little bit different down there.
So I guess what I'm getting at is there are a lot of things that can effect both a person's perception of maturity and the actual maturity of a deer.
If you want to define "true maturity", my guess is it would actually vary some depending on region.