It shall be unlawful for any person who is not a citizen of the United States or who has not declared his intention to become such, to hunt, shoot, capture, take, kill, trap, snare or in any manner destroy, wound or maim any wild bird or animal . . . except in defense of person or property; and to that end it shall be unlawful for any person who is not a citizen of the United States or who has not declared his intention to become such, to either own or be possessed of a shot gun or rifle of any make. Each and every person violating any provision of this Section shall upon conviction thereof, be sentenced to pay a fine of not less than twenty-five dollars, nor more than fifty dollars and costs of prosecution, or to serve not less than ten days nor more than thirty days in the county jail, or both such fine and imprisonment at the discretion of the court; provided that in addition to the before-named penalty, all guns of the before mentioned kinds found in the possession or under the control of such persons not citizens of the United States . . . shall upon conviction of such person, or upon his signing a declaration of guilt, be declared forfeited to the State of North Dakota and shall be sold as provided in this Act.