[ANNALS N. V. ACAD. Sci., VOL. XIII, No. I, pp. 73 to 360, Oct. 19, 1900. ] 



THE SEQUENCE OF PLUMAGES AND MOULTS OF 

 THE PASSERINE BIRDS OF NEW YORK 



JONATHAN DWIGHT, JR. 



(Read March 13, 1899) 



[Plates I to VII] 

 CONTENTS 



PAGE 



I. INDOOR STUDY OF MOULT 74 



FUNDAMENTAL PRINCIPLES 74 



DETERMINATION OF AGE BY OSTEOLOGICAL CHARACTERS 76 



WEAR OR FEATHER DISINTEGRATION 78 



II. PROCESS OF MOULT 82 



PROTECTIVE SEQUENCE IN FEATHER Loss 83 



ADVANCE OF MOULT IN THE FEATHER TRACTS 84 



1. Alar or Wing Tracts 87 



2. Humeral or Shoulder Tracts 93 



3. Capital or Head Tract 93 



4. Dorsal or Spinal Tract 94 



5. Ventral or Inferior Tract 95 



6. Caudal or Tail Tract.. 96 



7. Lumbar, Femoral or Thigh Tracts 97 



8. Crural or Leg Tracts 97 



III. EARLY PLUMAGES AND MOULTS OF YOUNG BIRDS 98 



IV. SEQUENCE OF PLUMAGES AND MOULTS 101 



1. Natal Down (Postnatal Moult) 105 



2. Juvenal Plumage (Postjuvenal Moult) 106 



3. First Winter Plumage (Prenuptial Moult) 107 



4. First Nuptial Plumage (Postnuptial Moult) 109 



5. Second or Adult Winter Plumage (Prenuptial Moult) 113 



6. Second or Adult Nuptial Plumage (Postnuptial Moult) 114 



V. COLOR FACTS versus COLOR THEORIES 116 



VI. OUTDOOR STUDY OF MOULT 124 



SEASONS OF MOULT 124 



MIGRATION AFTER MOULT 126 



PREPONDERANCE OF YOUNG BIRDS IN AUTUMN 128 



VII. PLUMAGES AND MOULTS OF NEW YORK SPECIES 130 



CLASSIFICATION OF MOULT 130 



DESCRIPTIONS OF SPECIES AND THEIR MOULTS 135 



VIII. BIBLIOGRAPHY 318 



(73) 



