Concerning to exhibit the key morphological variation between the quadrate bone in duck (mixed food eating bird) and Ibis (carnivorous bird), our study was performed on twenty adult duck (Anas domesticus) and Ibis (Bubulcus ibis) of both sexes. The birds heads were radiographically examined, Computed Tomographic (CT) studied, carefully dissected, described and compared. Also, the bones were prepared and measured. The gross morphological study showed that the quadrate bone in both species, was present between the upper bill and the mandible, it consisted of body and three processes; mandibular, otic and orbital. The body was star shape in duck and molar tooth-like in ibis. Cotyla quadratojugalis was present on the root, on the lateral aspect of lateral condyle in duck and ibis respectively. Condylus rostralis and Sulcus intercondylaris medalis was present in ibis only. The medial condyle was elongated in duck and heart-shape in ibis. The lateral jugalmandibular ligament was a broad, thick, terminated in the lateral cotyla and the dorsal border of the mandible in duck and ibis respectively. Radiological examination and Computed tomographic imaging of the quadrate bone was made for evaluation topographic anatomy of the bone. The results were discussed for better understanding the differences in shape, size, site and ligamental attachments between the two birds which may be correlated with the difference in feeding habits.