كم عدد الفقرات في العمود الفقري لطائر الحمام؟
The neck of a bird is composed of 13–25 cervical vertebrae enabling birds to have increased flexibility. A flexible neck allows many birds with immobile eyes to move their head more productively and center their sight on objects that are close or far in distance. Most birds have about three times as many neck vertebrae than humans, which allows for increased stability during fast movements such as flying, landing, and taking-off. The neck plays a role in head-bobbing which is present in at least 8 out of 27 orders of birds, including Columbiformes, Galliformes, and Gruiformes. Head-bobbing is an optokinetic response which stabilizes a birds surroundings as they alternate between a thrust phase and a hold phase. Head-bobbing is synchronous with the feet as the head moves in accordance with the rest of the body. Data from various studies suggest that the main reason for head-bobbing in some birds is for the stabilization of their surroundings, although it is uncertain why some but not all bird orders show head-bob. 
13–25