Upon request, real property which is under the jurisdiction or control of a Federal agency and no longer required by such agency, (1) can be utilized for wildlife conservation purposes by the agency of the State exercising administration over the wildlife resources of the State wherein the real property lies or by the Secretary of the Interior; and (2) is valuable for use for any such purpose, and which, in the determination of the Administrator of General Services, is available for such use may, notwithstanding any other provisions of law, be transferred without reimbursement or transfer of funds (with or without improvements as determined by said Administrator) by the Federal agency having jurisdiction or control of the property to (a) such State agency if the management thereof for the conservation of wildlife relates to other than migratory birds, or (b) to the Secretary of the Interior if the real property has particular value in carrying out the national migratory bird management program. Any such transfer to other than the United States shall be subject to the reservation by the United States of all oil, gas, and mineral rights, and to the condition that the property shall continue to be used for wildlife conservation or other of the above-stated purposes and in the event it is no longer used for such purposes or in the event it is needed for national defense purposes title thereto shall revert to the United States.