When a Carolina Wren like this one sings, something remarkable happens. These birds can sing so loudly that you almost have to shout to be heard over their songs!How can a bird like a Carolina Wren – at just 5½ inches long and weighing only as much as four nickels – produce so much sound? The answer lies in the songbird’s vocal anatomy. 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.