avifaunistic vs avifaunal

avifaunistic and avifaunal both are adjectives.

Word	Noun	Adjective	Verb	Adverb
avifaunistic	No	Yes	No	No
avifaunal	No	Yes	No	No

As adjectives, avifaunistic and avifaunal are synonyms defined as:

avifaunistic and avifaunal: of or relating to birds of a particular region or period

avifaunistic (adjective)	avifaunal (adjective)
of or relating to birds of a particular region or period	of or relating to birds of a particular region or period