SYL''TTD.E — THE SYLVIAS. 



79 



Poliopt'rj rfprulfn. 



^larch, but are not known to winter in that latitude. All the specimens 

 in the Smitlisonian collection were obtained between April and October, 

 except one from Southern California, wliich was taken in iJeceniber. 



Near Washington, Dr. Coues states the Blue-gray Gnatcatcher to be a 

 summer resident, amving during the tirst week ot" April, and remaining 

 until the latter part of September, during which 

 time they are very abundant. They are said 

 to breed in high open woods, and, on their first 

 arrival, to frequent tall trees on the sides of 

 streams and in orchards. 



In California and Arizona this species occurs, 

 but is, to some extent, replaced by a smaller 

 species, peculiarly western, P. mclanura. There 

 they seem to keep more about low bushes, hunt- 

 ing minute insects in small companies or in 

 l>airs, and their habits are hardly distinguish- 

 able from those of Warblers in most respects. 



The food of this species is chiefly small winged insects and their larvte. 

 It is an expert insect-catcher, taking its- prey on the wing with great 

 celerity. All its movements are very rapid; the bird seeming to be con- 

 stantly in motion as if ever in quest of insects, moving from one part of 

 the tree to the otlier, but generally preferring tlie upper branches. 



Xuttall and Audubon, copying Wilson, speak of the nest of this Gnat- 

 catcher as a very frail receptacle for its eggs, and as hardly strong enough to 

 bear the weight of the parent bird. This, however, all my observations 

 attest to be not the fact. The nest is, on the contrary, very elaborately and 

 carefully constructed ; large for the size of the bird, remarkably deep, and 

 with thick, w^arm walls composed of soft and downy materials, but abun- 

 dantly strong for its builder, who is one of our smallest birds both in size 

 and in weight. Like the nests of the Wood Pewee and the Humming-Bird, 

 they are models of architectural Ijeauty and ingenious design. With walls 

 made of a soft felted material, they are deep and purse-like. They are not 

 pensile, but are woven to small upright twigs, usually near the tree-top, and 

 sway witli each breeze, but the depth of the cavity and its small diameter 

 prevent the eggs from rolling out. Externally the nest is covered with a 

 beautiful periphery of gi\ay lichens, assimilating it to the bark of the decidu- 

 ous trees in which it is constructed. 



Occasionally these nests have been found at the height of ten feet from 

 the ground, but they are more frequently built at a much greater eleva- 

 tion, even to the height of fifty feet or more. They are made in the shape 

 of a truncated cone, three inches in diameter at the base and but two at the 

 top, and three and a half inclies in height. - The diameter of tlie opening 

 is an inch and a half. In Northern Georgia they nest about the middle 

 of May, and are so abundant that the late Dr. Gerhardt would often find 



