Female birds need to eat calcium to have enough of the mineral to lay their eggs. But it can be hard to find enough of it to eat in nature. We can help our backyard birds by offering them some extra calcium in bird feeders and by recycling our used egg shells.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.