Why do adult grebes feed feathers to their chicks?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Slavonian, or horned, grebe (Podiceps auritus) — Grebe Slavonian, or horned, grebe (*Podiceps auritus*)

Adult grebes feed feathers to their chicks shortly after hatching to establish a plug in the pyloric pocket of the stomach. This feather plug acts as a filter for material passing into the intestine. In adult grebes, these masses of feathers are also maintained in the stomach to help hold fish bones until they are fully digested.1