Faces and Structures


Bird Beaks

Bird

Bird (Photo credit: DeusXFlorida)

This week we will look at bird bills, at first I was just going to focus on chicken beaks, but then I decided to broaden my spectrum.  The beak, bill, or rostrum is an external anatomical structure which on birds is used for eating, grooming, manipulating objects, killing prey, fighting, probing for food, courtship, and feeding young. Although beaks vary significantly in size, shape, and color they share a similar underlying structure. Two bony projections—the upper and lower mandibles—are covered with a thin keratinized layer of epidermis known as the rhamphotheca. In most species, two holes known as nares lead to the respiratory system.  Inside the mouth, the oropharynx, contains the tongue, glottis, choana, palate, salivary glands, esophagus, opening of the avian equivalent of the Eustachian tubes (the pharyngotympanic tubes), and laryngeal mound.  

The tongue is adapted for collecting food, manipulating food and swallowing. For example, the tongue of the birds in the lory and lorikeet families is the most specialized of the parrots. The lory tongue is called a ‘”brush-tongue,” which refers to a cluster of elongated papillae that are normally only visible when the bird is feeding on liquid or soft foods, or when preening another bird.  At the base of the tongue, where the glottis and the laryngeal mound are located. The larynx of mammals is used for vocalization, but it is the syrinx, located down much further, that is responsible for sound production in birds.  Bird beaks are interesting structures all right, although usually not something you want near your face.

To see my video, click here