Whenever after due investigation the commission finds that game mammals, other than deer, and fur-bearing mammals and resident game birds have increased in numbers in any areas, districts, or portions thereof other than a refuge or preserve established by statute, to such an extent that a surplus exists, or to such an extent that the mammals or birds are damaging public or private property, or are overgrazing their range, the commission may provide by regulation, for a special hunting season for the mammals and birds, additional to, or concurrent with any other open season specified by law; or provide for increased bag limits; or remove sex restrictions specified by law.