NORTH AMERICAN MARSH BIRDS 99 



that of hybridism. Hybridism would seem to account satisfactorily 

 for the various specimens of wuerdemanni which have been taken, 

 especially if we assume, as seems reasonable, that hybrids between 

 such closely related species are fertile and might interbreed with pure- 

 blooded birds of either species, producing a great variety of interme- 

 diate specimens. A parallel case can be seen in the hybrids bet ween 

 the black duck and the mallard. 



I can not understand how anyone who is familiar with the great 

 white heron in life can have any doubt that it is a distinct species. 

 It is a strictly maritime species, its habitat is decidedly restricted and 

 its behavior is quite different from that of the Ward heron, with which 

 it mingles in the Florida Keys and doubtless interbreeds. 



Food. — The food of the great white heron seems to consist almost 

 entirely of fish, which it obtains in the shallow waters of the broad 

 bays and estuaries where it lives, always in salt water, I believe. A 

 number of these stately birds are often in sight at one time scattered 

 about singly, or in groups, over the shoals and mud flats, often a long 

 distance from the shore. I have never seen this heron walk about 

 when feeding as the others all do; it stands in patient, quiet dignity, 

 like a great white statue, waiting for its prey. When its appetite is 

 satisfied, or when the tide drives it from the flats, it flies off to some 

 favorite roosting place on an island fringed with mangroves, where it 

 rests among the dark green foliage until it is time to feed again. 



Probably other marine animal food is taken as well as fish. It has 

 a voracious appetite; Audubon (1840) mentions that two captive 

 young birds "swallowed a bucketful of mullets in a few minutes, each 

 devouring a gallon of these fishes." They also killed and swallowed 

 entire some young reddish egrets and Louisiana herons "although 

 they were abundantly fed on the flesh of green turtles." Again he 

 says: In the evening or early in the morning, they would frequently 

 set, like pointer dogs, at moths which hovered over the flowers, and 

 with a well-directed stroke of their bill seize the fluttering insect and 

 and instantly swallow it." They also killed and devoured young 

 chickens and ducks. 



Behavior. — The experiences which Audubon (1840) and others have 

 had with great white herons in captivity show them to be always 

 wild, untamable, and vicious, quite different in disposition from great 

 blue herons which are gentle and easily tamed. The white birds had 

 to be separated from the blue ones or the former would have kiUed 

 the latter. Even then, one of the white herons thrust his bill between 

 the bars of the coop in which the blue herons were confined and killed 

 one of them. "None of the sailors succeeded in making friends 

 with them." Again he says: "Once a cat which was asleep in the 

 smishine, on the wooden steps of the veranda, was pinned through the 



