Troglodytes aedon vs wren

Troglodytes aedon and wren both are nouns.

Word	Noun	Adjective	Verb	Adverb
Troglodytes aedon	Yes	No	No	No
wren	Yes	No	No	No

As nouns, wren is a hypernym of Troglodytes aedon; that is, wren is a word with a broader meaning than Troglodytes aedon:

Troglodytes aedon: common American wren that nests around houses
wren: any of several small active brown birds of the Northern Hemisphere with short upright tails; they feed on insects

Other hypernyms of Troglodytes aedon include jenny wren.

Troglodytes aedon (noun)	wren (noun)
common American wren that nests around houses	any of several small active brown birds of the Northern Hemisphere with short upright tails; they feed on insects