The only way we know a bird’s age for certain is by placing leg bands on it as a chick. After that, age is usually unknown. All bird band numbers and band colors are recorded at the USGS Banding Laboratory in Patuxent, Maryland.
Right: The oldest recorded Kolea, banded at Bellows Air Force Base, lived at least 21 years, 3 months. Because no one knew how old the bird was when banded, it may have been older.