Recent studies have shown that wild birds breeding in acidified areas have difficulties with obtaining sufficient calcium for their eggshells. and that the cause of it is the shortage of land snails. Many birds have to search for Ca-rich snail shells on a daily basis during egg production. Molluscs depend on litter calcium. https://www.markbroyard.com/super-value-krowne-18-x84-back-bar-drain-board-and-sink-sale-limited-save/