bird vs yell

bird and yell both are nouns.

As nouns, yell is a hypernym of bird; that is, yell is a word with a broader meaning than bird:

Other hypernyms of bird include call, cry, outcry, shout, vociferation.

bird (noun)	yell (noun)
warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings	a loud utterance; often in protest or opposition
the flesh of a bird or fowl (wild or domestic) used as food	a loud utterance of emotion (especially when inarticulate)
informal terms for a (young) woman
a cry or noise made to express displeasure or contempt
badminton equipment consisting of a ball of cork or rubber with a crown of feathers

bird (verb)	yell (verb)
watch and study birds in their natural habitat	utter a sudden loud cry
	utter or declare in a very loud voice