Gallinula chloropus vs swamphen

Gallinula chloropus and swamphen both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gallinula chloropus	Yes	No	No	No
swamphen	Yes	No	No	No

As nouns, swamphen is a hypernym of Gallinula chloropus; that is, swamphen is a word with a broader meaning than Gallinula chloropus:

Gallinula chloropus: black gallinule that inhabits ponds and lakes
swamphen: any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens

Other hypernyms of Gallinula chloropus include gallinule, marsh hen, water hen.

Gallinula chloropus (noun)	swamphen (noun)
black gallinule that inhabits ponds and lakes	any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens