The feathers of a bird are, for their weight, among the strongest structures in the world. The bones of this Magnificent Frigatebird weigh less than its feathers! To further reduce weight while maintaining strength, many bird bones are fused. In addition, the pectoral and pelvic girdles and ribs are joined to make a rigid box that supports those long wings, just as the wings support the bird.More info and transcript at BirdNote.org. Want more BirdNote? Subscribe to our weekly newsletter. Sign up for BirdNote+ to get ad-free listening and other perks. BirdNote is a nonprofit. Your tax-deductible gift makes these shows possible.