Crossword clues for ___ only a bird in . . . 4 lettersAnswerClueBIRDAudubon subjectBIRDFormer Celtics starBIRDNest builderBIRD39-Down, e.g.BIRDCrane or cuckooBIRDCoot or loonBIRDCelt #33BIRDWren or henBIRDWord that can precede the first words of 20-, 37- and 54-Across, and 11- and 33-DownBIRDAudubon painting subjectBIRDOne of the flockBIRD#33 for the CelticsBIRDFlier on a telephone pole, oftenBIRDBrit's chickBIRDMcHale teammateBIRDThe Hick From French LickBIRDHoliday entree, slangilyBIRDDuck, sayBIRDFormer Celtics star LarryBIRDParrot or sparrowBIRDShuttlecockBIRDDodo, for instanceBIRDCrane or kiteBIRDCeltics legendBIRDFeeder frequenterBIRDAviary's occupantBIRDDinosaur descendantBIRDLarry who may leap for a layupBIRDHe's Big on Sesame StreetBIRDLarry LegendBIRDCeltics starBIRDThe Celtics' #33BIRDCeltic No. 33BIRDParish partner?BIRDCelt who wore 33BIRDHall-of-Fame CelticBIRDRaven or robinBIRDWhat a U.K. hobbyist called a "twitcher" hopes to seeBIRDTraffic signal?BIRDGrebe, grackle, or grosbeakBIRDModern-day dinosaurBIRDOriole or cardinalBIRDGoose or loonBIRDGrackle or grosbeakBIRDBadminton projectileBIRDFrequent flierBIRDHeckle or JeckleBIRDNest egg protectorBIRDSee 19-AcrossBIRDCeltic hero