Moneys shall be transferred from a zoological park working cash fund to the zoological fund of the district only upon the authority of the forest preserve district board, which shall from time to time by separate resolution direct the district treasurer to make transfers of such sums as may be required for the purposes herein authorized. Every such resolution shall set forth (a) the taxes or other moneys in anticipation of the collection or receipt of which such transfer is to be made and from which such working cash fund is to be reimbursed, (b) the entire amount of taxes extended or which the board estimates will be extended, or received, for any year, in anticipation of the collection of all or part of which such transfer is to be made, (c) the aggregate amount of warrants or note theretofore issued in anticipation of the collection of such taxes together with the interest accrued and which the board estimates will accrue thereon and (d) the aggregate amount of moneys theretofore transferred from the working cash fund to the zoological fund in anticipation of the collection of taxes levied or to be received for any year, together with the aggregate amount of such anticipation tax warrants theretofore drawn against such taxes and the amount of the interest accrued and estimated to accrue on such warrants or notes and the aggregate amount of such transfers theretofore made in anticipation of the collection of such taxes, shall not exceed 90% of the actual or estimated amount of such taxes extended or to be extended, or to be received, as set forth in such resolution.
     To the extent that at any time moneys are available in the working cash fund they shall be transferred to the zoological fund and disbursed for the payment of salaries and other zoological expenses so as to avoid, whenever possible, the issuance of anticipation tax warrants or notes.