LIFE HISTORIES OF 

 NORTH AMERICAN WOOD WARBLERS 



Order PASSERIFORMES: Family PaRULIDAE 



By ARTHUR CLEVELAND BENT 

 Taunton, Mass. 



GENERAL REMARKS ON THE FAMILY PARULIDAE 



CONTEIBUTED BY WiNSOR MaRBETT TyLEB 



The family of wood warblers, Parulidae, is the second largest family 

 of North American birds, surpassed only in number of species by the 

 family Fringillidae. The wood warblers occur only in the Western 

 Hemisphere ; they are distinct from the Old World warblers, Sylviidae, 

 although the two families play a similar role in nature's economy. 



The wood warblers are largely nocturnal migrants, whose long 

 journeys in the dark of night over sea and lake and along the coast 

 expose them to many perils, one being the lighthouses they strike 

 with frequently fatal results. Their notes are seldom heard from the 

 night sky during their spring migration, but on many a calm, quiet 

 night in August and September, as they fly overhead, their sharp, 

 sibilant, staccato notes punctuate the rhythmic beat of the tree-crickets 

 singing in the shrubbery and stand out clearly among the soft, whistled 

 calls of the migrating thrushes. 



The length of migration varies greatly; the pine warbler with- 

 draws in winter only a short distance from the southern limit of its 

 breeding range, whereas the most northerly breeding blackpolls mi- 

 grate from Alaska to the Tropics. In spring many species migrate at 

 nearly the same time, apparently advancing northward in intermit- 

 tent waves of great numbers during favorable nights. Flocks made 

 up of sometimes a dozen species together flash about in their bright 

 plumage during the week or two at the height of the migration and 

 furnish days of great excitement to ornithologists. Their return in 

 late summer and autumn is more leisurely and regular ; in loose flocks 

 they drift slowly by for several weeks, their southward passage evi- 

 dent even in daytime. The flocking begins early, soon after nesting is 

 over, and to the north is apparent early in July, if closely watched for, 

 even before the leaves begin to wither. The mixed fall flocks, with 

 adults in winter plumage and young birds in duller colors, present 

 many fascinating problems in identification as the birds move quietly 

 along. 



