Refers specifically to the bird species Cygnus atratus. Used in both everyday and scientific contexts.
There is a black swan in the park pond.
The black swan is a bird native to Australia.
白鳥 refers to the white swan, while 黒鳥 refers to the black swan, the color-contrasted counterpart species name.
Standard kanji spelling; the reading こくちょう is the primary pronunciation.
Katakana spelling used especially in biological contexts or for emphasis.
Compound of 黒 (black) and 鳥 (bird). The reading こくちょう is the on'yomi of the kanji.