What changes the food answer
Offer cuttlebone only as one small part of a species-appropriate diet. It can help with calcium access and beak activity, but the main diet still has to be right.
Who may benefit
Budgies, cockatiels, canaries, finches, and some other birds may use cuttlebone. How much they need depends on species, diet, age, hormones, and egg laying.
Watch egg-laying birds closely
A hen that is laying eggs, straining, weak, fluffed up, or sitting low needs avian-vet advice. Cuttlebone alone is not enough for an egg-binding risk.
Keep it clean and useful
Mount it securely, replace dirty or ignored pieces, and do not let loose fragments sit in wet food or water.
Best default
Use cuttlebone as optional support, not as proof that the diet is balanced.