200 CHARACTERISTICS OF WARBLERS 



offer any difficulty in the way of discrimination of species, 

 when in perfect plumage ; that is to say, their ' specific char- 

 acters " are well marked. They are also well aware, that none of 

 our birds are more strictly and completely migratory than 

 these ; probably none of our species reside permanently in any 

 one locality. Putting this and that together, it is easy to infer, 

 as I think we may with entire accuracy, that the integrity of 

 the species depends upon their migrations, for they are never 

 continuously subjected to modifying local influences. Migration 

 holds species true; localization lets them slip. That the inherent 

 susceptibility to variation is not less in this family than else- 

 where, is shown by the fact that the few localized forms respond 

 as usual to modifying influences. Take the exotic races of 

 Qeothlypis trichas or Dendrceca petechia in instance. The Vireos, 

 noted for the constancy of their slight though obvious specific 

 characters, offer a parallel case. For the converse, the student 

 may be reminded of the cases of such sedentary birds as species 

 of Picus and various Fringillidce, which "run into each other" 

 from one faunal area to another. 



Musical proficiency might be reasonably presupposed in a 

 group of birds known by the delightfully suggestive name of 

 " warblers ". It is quite our own fault, however, that they are 

 misnamed; we have simply perpetuated an early blunder in 

 classification, by which these birds were referred to the Old 

 World genus Sylvia. We have corrected the technical mis- 

 nomer of "Sylvia", but have been less precise in our vernacu- 

 lar. Nothing less like warbling than the songs of our "war- 

 blers" can well be imagined. Bluebirds and Wrens warble or 

 trill their lays ; Warblers, as a rule, do not. There are few 

 great singers among them all. Their voice usually is thin, sharp, 

 "unsympathetic"; the pitch is too high; the notes are abrupt 

 and jerky ; movement is uneven and never long-sustained. The 

 song indeed has musical quality, and may affect us rather pleas- 

 antly ; but our attention is more likely to be arrested by its 

 oddity than attracted by its melody. I cannot but criticise 

 here ; yet I am ready to bear witness to the endless variety of 

 the songs of the Warblers, probably every species has its own, 

 distinctly recognizable by the practised ear ; and much of the 

 pleasurable excitement which the study of these birds affords, 

 comes from the effort of discriminating between their wonder- 

 fully varied performances. Probably no single ornithologist 

 has learned them all even all those to be heard in his own 



