song vs birdcall

song and birdcall both are nouns.

Word	Noun	Adjective	Verb	Adverb
song	Yes	No	No	No
birdcall	Yes	No	No	No

As nouns, song and birdcall are synonyms defined as:

Other synonyms of song include birdsong, call.

song (noun)	birdcall (noun)
the act of singing	a device for imitating a birdcall
a short musical composition with words	the characteristic sound produced by a bird
the characteristic sound produced by a bird
a distinctive or characteristic sound
a very small sum