winter wren vs jenny wren

winter wren and jenny wren both are nouns.

Word	Noun	Adjective	Verb	Adverb
winter wren	Yes	No	No	No
jenny wren	Yes	No	No	No

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

winter wren: small wren of coniferous forests of Northern Hemisphere
jenny wren: any of several small active brown birds of the Northern Hemisphere with short upright tails; they feed on insects

Other hypernyms of winter wren include wren.

winter wren (noun)	jenny wren (noun)
small wren of coniferous forests of Northern Hemisphere	any of several small active brown birds of the Northern Hemisphere with short upright tails; they feed on insects