- Belted Kingfisher Pellet-casting shows a male kingfisher regurgitating a pellet.
- This interesting section from Kelly, J. F., E. S. Bridge, and M. J. Hamas (2009). Belted Kingfisher (Megaceryle alcyon), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.84 explains this process:
Drinking, Pellet-Casting, and Defecation
Like most fish-eating birds, kingfishers have no crop. The distensible gizzard is lined with thin muscles that are unfit for vigorous grinding. Prior to development of flight feathers, nestlings digest all bones and scales of ingested fishes. By the time young are ready to leave the nest, digestion of bones ceases and pellets consist of complete skeletons and scales of fishes that have been eaten. Chitinous parts of insects are also disgorged. The inability of older birds to digest bones and scales suggests that gastric reactions change from acid to alkaline (White 1939b).
Disgorged pellets are compact and keep their shape for several days (White 1936). Pellets are usually regurgitated near feeding places, often repeatedly from the same perch, making it possible to ascertain what prey are taken even if kingfishers are not present. Fish scales in pellets also provide age determination of most fishes.
