Archaic word for 'crane' (the bird). The modern standard word is 鶴 (つる). Found in classical poetry and old texts.
See also: 鶴
The bird called 'ashitazu' in old poems is what we now call a crane.
The exact derivation is uncertain. The kanji 葦田鶴 literally mean 'reed-field crane', possibly a poetic or descriptive name. The reading あしたず is archaic and not used in modern Japanese.