NO. 1939. REVISION OF ARDEA HERODIAS—OBERnOLSER. 533 



adjoining Ardea Tierodias treganzai, of Arizona, or the also intervening 

 Ardea herodias hyperonca ^ of California. All but three of the races, 

 Ardea herodias sanctilucae, Ardea herodias cognata, and Ardea herodias 

 oligista,^ have a range of considerable, in some cases, of wide extent, 

 as seems to be often the case with large bu"ds which wander about 

 over a large area. The size of the various races does not seem 

 to correspond with any regularity to geographic conditions, for 

 while the southernmost form, Ardea herodias cognata, of the Gala- 

 pagos Islands, is of small size, the smallest race is Ardea herodias 

 oligista,- of the Santa Barbara Islands; whde on the adjacent Cali- 

 fornia mainland is one of the largest, Ardea herodias hyperonca,^ be- 

 yond which, in the northernmost subspecies, Ardea herodias fannini, 

 lives a l)ird of only medium size. Furthermore, the Floridian 

 Ardea herodias wardi is larger than either Ardea herodias adoxa ^ 

 from the West Indies, or Ardea herodias herodias from the north- 

 eastern United States, 



The adult female of Ardea herodias is identical in color with the 

 male, but averages smaller. Individual variation is slight, and con- 

 sists principally in size, and in the color of neck and back. Seasonal 

 change in plumage is likewise insignificant, probably because of the 

 little wear to which the plumage is subject; and, though the neck 

 sometimes becomes a little lighter in late summer, the back and 

 other parts seemingly undergo little or no change. Apparently 

 soon after the j^oung are hatched, however, the color of the bare 

 skin around the eye in the adult changes to yellowish green, and 

 the maxilla becomes almost entirely dusky olive, leaving only its 

 tomia and the mandible yellowish. 



The young bird in first complete (i. e., juvenal) plumage differs 

 considerably from the adult in having the whole pileum and upper 

 sides of head dull, dark brown or brownish black; the entire neck 

 and lower half of the sides of head much spotted or washed with buff", 

 ochraceous, tawny, or chestnut; ground color of neck dull gray with- 

 out any drab tinge; upper parts of body, wings, and tail, duller, 

 more brownish, the long, plumelike development of dorsal and 

 scapular feathers lacking; superior wing-coverts tipped or terminally 

 spotted wdth ochraceous or tawny; edge of wing paler and more 

 mixed with white; thighs somewhat lighter; breast and abdomen 

 white, streaked broadly with gray and slate color, and more or less 

 mixed with cinnamon rufous or buff; jugular plumes wanting; and 

 the tufts on sides of breast gi'ay striped with white; iris gamboge 

 yellow; eyelids and bare horizontal lore space light apple green; 

 maxilla black or blackish, the tomium brownish or horn color; 

 mandible pale pea green, passing into clear horn 3'ellow on the ter- 



i See p. 550. 6 See p. 553. * See p. 544. 



