tree sparrow vs sparrow

tree sparrow and sparrow both are nouns.

Word	Noun	Adjective	Verb	Adverb
tree sparrow	Yes	No	No	No
sparrow	Yes	No	No	No

As nouns, sparrow is a hypernym of tree sparrow; that is, sparrow is a word with a broader meaning than tree sparrow:

tree sparrow: Eurasian sparrow smaller than the house sparrow
sparrow: any of several small dull-colored singing birds feeding on seeds or insects

Other hypernyms of tree sparrow include true sparrow.

tree sparrow (noun)	sparrow (noun)
Eurasian sparrow smaller than the house sparrow	any of several small dull-colored singing birds feeding on seeds or insects
finch common in winter in the northern U.S.	small brownish European songbird