fabulous mythical bird
鶼 refers to a fabulous mythical bird, a creature of legend rather than a real animal.
鶼 combines 兼 (possibly contributing sound) with 鳥 (bird), forming a character for a mythical bird. The exact historical origin is uncertain.
The left side 兼 suggests something combined or doubled, and the right side 鳥 is a bird. Imagine a fabulous bird that combines features of many birds into one mythical creature.
For ケン, picture Ken the mythical bird-keeper holding a fabulous bird on his arm: Ken -> ケン.