Fulica americana vs mud hen

Fulica americana and mud hen both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fulica americana	Yes	No	No	No
mud hen	Yes	No	No	No

As nouns, Fulica americana and mud hen are synonyms defined as:

Other synonyms of Fulica americana include American coot, marsh hen, water hen.

Fulica americana (noun)	mud hen (noun)
a coot found in North America	a coot found in North America