mynah
鴝 refers specifically to the mynah bird, a type of bird known for its ability to mimic sounds.
鴝 combines 句 (phrase, sound) with 鳥 (bird), likely indicating a bird known for vocal sounds, fitting the mynah's mimicking ability. The exact historical development is uncertain.
A bird (鳥) that can repeat phrases (句) is a mynah: 鴝.
For ク, imagine a mynah bird cooing softly: coo -> ク, and the bird mimics the sound.