Source : Webster's Revised Unabridged Dictionary (1913)

Ornithologic \Or`ni*tho*log"ic\, Ornithological
\Or`ni*tho*log"ic*al\, a. [Cf. F. ornithologique.]
   Of or pertaining to ornithology.

Source : WordNet®

ornithological
     adj : of or relating to ornithology; "her ornithological
           interests"