OF EASTERN PENNSYLVANIA. 145 



small numbers of this species are resident through- 

 out the entire year. Such is not the case in our 

 latitude, as far as our observations have extended. 



Seiurus ludovicianus, Bonap. 



The Louisiana Water Thrush is an uncommonly 

 rare species in eastern Pennsylvania. Like its 

 nearest congener which we have just spoken of, 

 it inhabits the margins of creeks, swampy grounds, 

 and low damp woods. It is pre-eminently the 

 quickest, as well as the most restless of the Sylvi- 

 colidt? though mainly terrestrial in its habits. When 

 observed upon the wet ground, the posterior part 

 of its body is somewhat elevated, and is being con- 

 stantly tilted up and down. It makes its appear- 

 ance about the middle of May, and during its stay, 

 it is exceedingly shy and suspicious. When started 

 it flies up suddenly with a sharp and startling chat- 

 ter. 



Its, flight is easy, continued, and low; whereas 

 upon the ground it has a graceful walk. 



The song of this species is rich, loud, vivacious. 

 It begins very high and falls with a gentle grada- 

 tion, until the last notes are scarcely articulated. 

 When singing it perches upon the lower branches 

 of a tree overhanging the water, which it occa- 

 sionally deserts for the topmost boughs. Audubon 

 speaks of its notes as rivalling those of the night- 

 ingale in mellowness, variety, and power. The 

 call-note is a simple sparrow-like chirp. 



Insects and their larvae are mainly its diet. 



J 



