Is there a true definition of " yearling?" Some people call a yearling a 1.5 year old deer....around here a yearling is this years fawn, not 1.5 year old deer. It seems to me that it would make sense to call a deer that is less than 1 year old a yearling....after that you' ve got age like 1.5, 2.5, etc. While a 1.5yo deer isn' t totally ' mature' it is almost ' mature' and has adult size, looks, breeding ability, etc. I would think that this stage in a deers life would be the adolescent stage. What are your thoughts?