LOUISIANA WATERTHRUSH 497 



breast streaks diminished." Subsequently plumages are acquired by 

 a complete postnuptial molt in July and by wear during the winter, 

 the winter plumages of old and young birds being practically indis- 

 tinguishable. 



The sexes are alike in all plumages, and the molts are the same. 



/?'^^^._"Examination of the stomachs of 4 birds of this species 

 from Florida showed their food to consist chiefly of insects and 

 spiders. The insects included dragon flies, crane-fly larvae, grouse 

 locusts, beetles, bugs, ants, caterpillars, and scale insects. Two of the 

 birds had eaten small moUusks, and one had taken a killifish" 

 (Howell, 1932). 



Five stomachs, collected in Puerto Rico by Dr. Wetmore (1916), 

 contained 98 percent animal matter and 2 percent vegetable food. 

 "Remains of flies (33 percent) were present in three stomachs. Water 

 beetles (Parnidae and others) were found in three stomachs and leaf 

 beetles in two. In one bird was a tree hopper and in two others were 

 indeterminate bug remains. A dragon fly was found once and spider 

 remains and bits of a scorpion twice. Three-fourths of the contents 

 of one stomach was composed of fragments of a snail, and in another 

 was found a tree toad {Eleutherodactylus sp.). Two birds had eaten 

 seeds, in one case those of the aji {Ca'psicum sp.) ." 



Behavior. — The two species of waterthrushes are much alike in 

 their habits and movements ; both of them are walkers and both have 

 the peculiar habit of tilting the tail upward as if a spring holding it 

 down had been suddenly released ; both spend most of their time on 

 or near the ground walking gracefully along the margins of streams 

 or pools, or even in the shallow water, seemingly as devoted to the 

 vicinity of water as is the water ouzel to the western mountain streams. 

 Dr. Mearns (1879) describes the behavior of the Louisiana water- 

 thrush very aptly as follows : 



It runs about (never hopping) over tlie stones and moss, gleaning along the 

 sandy margin of the sti"eam. Occasionally you may see it alight upon the 

 witch-hazel, or alder bushes, that border the water, running dexterously along 

 their branches. It always accompanies every employment with a Sandpiper- 

 lilie, tilting motion of its body. Now it starts off in pursuit of one of its 

 fellows. They fly through the forest with astonishing velocity, uttering a sharp 

 twittering note, that sounds like the noise produced by striking two pebbles 

 together. As they emerge higher up the stream, the chase is relinquished for 

 the time, and you are surprised as they fly past to hear the clear notes of its 

 song uttered as distinctly in mid-air as when perched; then the chase is re- 

 newed, but as they fly back again, one of the birds rises high up in the air above 

 its pursuer, and then flutters slowly downward, pouring out its sweet song as 

 it descends, mingling its cadence with the sound of the brook— the whole effect 

 in perfect harmony with the spirit of the place. These performances take place 

 oftenest early in the morning, about sunrise. 



