In the chicken, and likely other gallinaceous birds, the sternum, humerus, pelvis, cervical and thoracic vertebrae are pneumatic.
https://www.pheasant.com/Portals/0/...bert Porter PDF.pdf?ver=2019-09-05-135230-327
https://www.pheasant.com/Portals/0/...bert Porter PDF.pdf?ver=2019-09-05-135230-327