What does the cryptic crossword clue "American diver – turkey, dodo or drongo? (4)" mean?

The definition is "American diver turkey, dodo or drongo". The wordplay uses a double definition. Double definition The answer is LOON.

American diver – turkey, dodo or drongo? (4)

Guardian Cryptic #29282 | 24 Down | 2024-01-18 flower