NORTH AMERICAN MARSH BIRDS 207 



vary from "pallid mouse gray" to pure white. The white occipital 

 plumes are often present in the fall, but less highly developed. 



Food. — ^As its name implies, the night heron feeds largely at night, 

 or during the dusk of evening and before sunrise. It is a common 

 experience to hear its familiar croaking notes, as it flies overhead 

 during the evening, to or from its feeding grounds. During the 

 nesting season, when the young demand an extra amount of food, 

 it is necessary for their parents to spend more time in search of food 

 and they are kept busy all day and probably most of the night. But 

 the niglxt heron is by no means wholly nocturnal in its feeding habits 

 at any season. It may be flushed at any time during the day, even 

 late in the fall from favorable feeding grounds around the marshy 

 borders of ponds or along the reedy banks of streams. On the sea- 

 ■coast it is largely influenced by the tides and may be seen at low tide 

 out on the mud flats or around the fish weirs; and it knows at just 

 what stages of the tides it can fish to best advantage in the shallows 

 of the tidal creeks. 



Audubon (1840) says that "it is never seen standing motionless, 

 waiting for its prey, like the true herons, but it is constantly moving 

 about in search of it. " This active method may be the one employed 

 wlien in search of the less active aquatic animals on which it feeds; 

 but when fishing, I believe, it usually stands still, in shallow water, on 

 the shore, or on some convenient perch. I once saw a young night 

 heron given a lesson in still fishing by, presumably, one of its parents. 

 Both birds had been standing as motionless as statues, for some time 

 in the shallow water of a tidal creek; the young bird began to show 

 its impatience by moving its head slightly from side to side; then 

 it took a few steps forward, slowly and stealthily, with its neck 

 stretched out and crouching close to the water; whereupon the adult, 

 which had stood immovable, flew at the young bird, with loud, scold- 

 ing croaks, and struck it some hard blows on the back with its bill. 

 The young bird was forced to fly, but it settled again a few yards 

 away and did not attempt to move again ; perhaps it had learned its 

 lesson. 



Doctor Gross (1923) determined that at Sandy Neck about 80 per 

 cent of the night herons' food consists of fish, the commonest species 

 being "whiting {Merlucceus hilinearis) , herring (Clupea harengus), and 

 runners ( Tantogolahrus adspersus)." "Many of the whiting and some 

 •other fishes wore picked up dead on the beaches. Among the other 

 fish taken were a few small flounders, an occasional mackerel and even 

 sculpins, sea robins, and puffers. Many of these were taken from 

 the fish weirs. Other kinds of fish, such as perch, carp, pickerel, and 

 ■eels, have been reported by other observers. Probably fish consti- 

 tute the bulk of the food everywhere and whatever species are easily 

 available are taken. 



