The cere (from the Latin cera: wax)^[1] or operculum^[2] is a soft, fleshy swelling found on the beaks of certain birds. Hawks, parrots, doves, skuas and budgerigars are among the birds that have ceres. The word 'cere' is often used synonymously with 'beak', although the two are not identical. The cere plays a role in indicating the reproductive stage of certain dimorphic birds, and also has a key function in respiration.

The Rock Pigeon, Columba livia. The cere is located at the top of the beak, and is a distinctive white-grey colour.

[edit] Physical characteristics

The cere is located at the top of the beak,^[2][3] and is often waxy in texture. The colour of the cere may vary from species to species, and also depends on the season.^[4] The cere contains the nares (nostrils). The shape of the cere varies from species to species. In falcons, the opening of the nares is roughly circular in shape.^[2]

[edit] Role in respiration

The nares are located within the cere. The nares connect to the inner beak, which is in turn connected to the respiratory system.^[5] Thus, the cere plays an important role in respiration, and the protection of the nares.

[edit] Role in indication of reproductive cycle

Budgerigars are dimorphic in that the males' ceres turn bright blue upon maturity, while the females' ceres turn tan.^[4] The female budgies' ceres also appear wrinkled, to a greater extent during periods of fertility. Immature budgies have pale pinkish ceres which are smooth and shiny.^[4]

[edit] References

[edit] See also

Beak