18 THE BIRDS OF NEW JERSEY. 



After the first of April, however, the strictly summer 

 species and transients begin to arrive. There are general- 

 ly several well marked waves during the month, their 

 most characteristic species being the Hermit Thrush, 

 Ruby-crowned Kinglet, Chipping Sparrow. Chimney 

 Swift, Barn Swallow, Bank Swallow, Myrtle Warbler, 

 House Wren, Thrasher, Chewiuk, Black and AVhite Warb- 

 ler, Maryland Yellow-throat and Solitary Yireo. 



A number of other species sometimes arrive during the 

 last week in April, when there often occurs a wave which 

 seems to be a forerunner of the great "Thrush and 

 Warbler waves" of May, which brings the first stragglers 

 of many species which are really characteristic of the 

 latter month. 



The following list includes such species as have been 

 noted — generally in smaller numbers — from April 20 to 

 30 in the vicinity of Philadelphia, but which do not arrive 

 in force until May: 



Kingbird, Black- throated Green Warbler, 



Crested Flycatcher, Parula Warbler, 



Orchard Oriole, Water Thrush, 



Scarlet Tanager, Catbird, 



Red-eyed Yireo, Wilson's Thrush, 



Yellow Warbler, Wood Thrush. 



About the first of May the species just mentioned, to- 

 gether with many Warblers, etc., arrive in abundance 

 and form the first great "Warbler wave." Thousands of 

 Thrushes, Warblers and Yireos pass through at this time 

 and the woods seem fairly alive with birds. Several other 

 waves occur during May, which are mainly characterized 

 by Warblers, and, indeed, for the first three weeks of the 

 month these birds seem to be passing almost continuous- 

 ly. By the 20th of the month, however, the migration 

 begins to wane, and although stragglprs of many species 

 are seen until the 80th, and some Blackpoll Warblers 

 linger as late as June 6, there are rarely any migratory 

 waves after May 20. 



