hunting vs birdnesting

hunting and birdnesting both are nouns.

Word	Noun	Adjective	Verb	Adverb
hunting	Yes	No	No	No
birdnesting	Yes	No	No	No

As nouns, birdnesting is a hyponym of hunting; that is, birdnesting is a word with a more specific, narrower meaning than hunting:

hunting: the work of finding and killing or capturing animals for food or pelts
birdnesting: hunting for birds' nests to get the eggs

Other hyponyms of hunting include canned hunt, stalk, stalking, still hunt, predation.

hunting (noun)	birdnesting (noun)
the work of finding and killing or capturing animals for food or pelts	hunting for birds' nests to get the eggs
the pursuit and killing or capture of wild animals regarded as a sport
the activity of looking thoroughly in order to find something or someone