darter vs water turkey

darter and water turkey both are nouns.

Word	Noun	Adjective	Verb	Adverb
darter	Yes	No	No	No
water turkey	Yes	No	No	No

As nouns, water turkey is a hyponym of darter; that is, water turkey is a word with a more specific, narrower meaning than darter:

darter: fish-eating bird of warm inland waters having a long flexible neck and slender sharp-pointed bill
water turkey: blackish New World snakebird of swampy regions

Other hyponyms of darter include Anhinga anhinga.

darter (noun)	water turkey (noun)
a person or other animal that moves abruptly and rapidly	blackish New World snakebird of swampy regions
fish-eating bird of warm inland waters having a long flexible neck and slender sharp-pointed bill