ORIGINAL ARTICLE Gross Anatomical Features of the Gastrointestinal Tract (GIT) of Blue and Yellow Macaws (Ara ararauna) – Oral Cavity and Pharynx J. Aizawa 1 , C. Tivane 1 , M. N. Rodrigues 1 , P. G. Wagner 2 , D. B. Campos 3 , R. R. Guerra 3 and M. A. Miglino 1 * Addresses of authors: 1 Faculdade de Medicina Veterin aria e Zootecnia (FMVZ), Universidade de S~ ao Paulo (USP), S~ ao Paulo, Brasil; 2 Centro de Triagem de Animais Silvestres do IBAMA-PB (CETAS-PB), Para  ıba, Brasil; 3 Universidade Federal da Para  ıba (UFPB), Para  ıba, Brasil *Correspondence: Tel.: +55 11 30917690; Fax: +55 11 210224; e-mail: miglino@usp.br With 2 figures Received July 2012; accepted for publication December 2012 doi: 10.1111/ahe.12032 Summary Morphological studies of the gastrointestinal tract (GIT) of blue and yellow macaws (Ara ararauna) are scarce. Therefore, this study aims to describe the macaw’s oropharyngeal cavity in order to supply the deficiency of anatomical data and as part of a broad study of the GIT of these birds. Two male and one female adult blue and yellow macaws were anatomically dissected to expose the oropharynx. The macaw oropharynx was ‘V-shaped’ and flattened laterally being composed of maxillary and mandibular rhamphotheca of the beak. The tongue, lingual frenulum and laryngeal mound (containing ‘spindle-shaped’ glottis and prominent mucosal papillae) formed the floor of the oropharynx. The roof revealed two distinct regions separated by a ‘step-like depression’, whereas in the floor, the mandibular rhamphotheca was separated from the oral cavity mucosa by a large vestibulum enclosing the lingual frenulum. The palate was hard without any signs of rugae nor palatine raphe. A smooth ridge extended caudally from the choana to the common opening of the Eustachian tubes. This study, in addition to confirming the basic features of the orophar- ynx previously described for birds in general, provided new, unreported mor- phological data, some of which may be important when studying nutrition and health of these birds. Introduction Brazil is the country with the major number of Psittaci- dae birds in the world. The parakeets, parrots and macaws are part of this family, the latter being the most representative of the group. The blue and yellow macaws (Ara ararauna) can measure up to 80 cm long, exhibiting blue colour in the top feathers, yellow colour in the bot- tom feathers and lines of black feathers in the neck and face. The macaw’s beak is strong, curved, black coloured and large and corresponds to 19% of the weight of the bird; it is often used as a third leg for food seeking. Addi- tionally, the thick and sensitive tongue is used as a tactile organ (Sick, 1997). In recent studies related to Ara ararauna, aspects such as activity, animal husbandry, feeding habits and habitat have been discussed. However, morphological data regarding digestive system of this bird remain unclear. The Ara ararauna is extremely important species of Brazilian wildlife and also in other countries of the world where this bird is raised (Tubelis, 2009). The Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) regulates trade in wildlife animals coming from breeding, the fact that increases the use of these animals as pets (Valle et al., 2008). It is believed that any information on the digestive tract of the macaw could improve the raising and management of these birds as pets or exotic animals especially for professionals working in the management, nutrition and husbandry of this species. In this view, this study will describe in detail macroscopic features of the oropharyngeal cavity of the © 2013 Blackwell Verlag GmbH Anat. Histol. Embryol. 1 Anatomia, Histologia, Embryologia