Comparative studies of the dorsal surface of the tongue in three avian species by scanning electron microscopy.

The dorsal lingual surfaces of adult Blue-and-White Flycatcher, Hawfinch, and Japanese White-eye were examined by scanning electron microscopy. The tongue of the Blue-and-White Flycatcher shows a conical shape and a median groove is observed on the anterior lingual apex. The tongue of the Hawfinch shows a cuspid-like shape and a median groove and separation of the lingual apex are not observed. Many processes are observed in the tip of the tongue of the Japanese White-eye. Results of morphological studies indicate a close correlation between the shape of the tongue and the method of food intake, type of food, and bird's habitat.