108 BULLETIN 135^ UNITED STATES NATIONAL MUSEUM 



and the thighs are " light pinkish cinnamon." All of the colors named 

 above vary somewhat, as in the adults of the various subspecies. 



The above plumage is worn through the first fall and winter with- 

 out much change before February, when the first spring plumage 

 begins to show advance toward maturity; at this season one or two 

 occipital plumes may appear, but the crown remains black; rudimen- 

 tary plumes appear on the breast and back; the buff edgings have 

 worn away and some new feathers have replaced the old in the man- 

 tle; and the under parts are more like the adult. 



At the first postnuptial molt, which is complete, the following 

 summer and fall, further advance toward maturity is made; the 

 forehead becomes partially white, some occipital plumes are acquired ; 

 the black shoulder tufts appear, somewhat mixed with white; many 

 long, narrow plume-like feathers appear in the back and breast; the 

 thighs are purer cinnamon; and the neck and under parts are more 

 like those of the adult. This is the second winter plumage, which be- 

 comes nearly adult at the next prenuptial molt, when the young bird is 

 ready to breed. After the next complete postnuptial molt, when the 

 young bird is over two years old, the plumage becomes fully adult, 

 though signs of immaturity are still to be seen, such as dusky markings 

 in the white crown and white markings in the black shoulder tufts; 

 these may not wholly disappear for another year or two. 



Adults have a complete postnuptial molt in late summer and fall 

 and a partial prenuptial molt of the contour feathers in late winter 

 and early spring. There is little seasonal change in adults except 

 that in spring the plumes of the head, breast, and back are more 

 fully developed and perhaps the showy colors are a little more bril- 

 liant. The adult is a handsome bird at all seasons. 



Food. — The principal food of the great blue heron is fishes of vari- 

 ous kinds and it seems to be willing to accept whatever kind of fish 

 is most easily available. Ora W. Knight (1908) says: 



Frogs, eels, horn-pouts, pickerel occasionally, suckers, shiners, chubs, black 

 bass, herrings, water puppies, salamanders, and tadpoles, are the items I have 

 discovered among their rations. They do not frequent as feeding grounds the 

 spots where trout usually congregate, and I have very strong doubts that they 

 eat trout, except very rarely, let alone consuming them in the vast quantities cer- 

 tain persons have affirmed. 



It fishes by night as well as by day and employs two very different 

 methods, still hunting and stalking. The former is the best known and 

 probably the commonest method. Standing as still as a graven 

 image in shallow water, where fish arc moving about, it waits patiently 

 until one comes within reach, when a swift and uneiTing stroke of its 

 well trained bill cither kills or secures the fish. Usually the fish is 

 seized crosswise between the mandibles; if it is a small one, it is 

 tossed in the air and swallowed head first, so that it will slip down 



