oyster catcher vs shorebird

oyster catcher and shorebird both are nouns.

Word	Noun	Adjective	Verb	Adverb
oyster catcher	Yes	No	No	No
shorebird	Yes	No	No	No

As nouns, shorebird is a hypernym of oyster catcher; that is, shorebird is a word with a broader meaning than oyster catcher:

oyster catcher: black-and-white shorebird with stout legs and bill; feed on oysters etc.
shorebird: any of numerous wading birds that frequent mostly seashores and estuaries

Other hypernyms of oyster catcher include limicoline bird, shore bird.

oyster catcher (noun)	shorebird (noun)
black-and-white shorebird with stout legs and bill; feed on oysters etc.	any of numerous wading birds that frequent mostly seashores and estuaries