As Bobolinks return to North America from the tropics each spring, they have good reason to sing with joy. The two-ounce birds have completed one of the longest migrations of any songbird: roughly 6,000 miles.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.