PASSERINE BIRDS OF NEW YORK - 81 



Purple Finch {^Carpodaais piirpiirais) and the American Cross- 

 bill {Loxia curvirostra niinor^ figured on plate VII which 

 shows at a glance what has occurred. Ordinarily in most spe- 

 cies, wear removes the barbs, bit by bit, so that each terminates 

 in a V^ formed by the barbules on either side. In the case 

 of these two as well as other species, the barbs of certain 

 feathers are blunt and heavy and the barbules are gradually 

 lost, leaving them bare. Such barbs are apparently brighter 

 red than when the grayish barbules between them produce an 

 effect that to the eye is pinkish. This is the "brightening" 

 that has also been observed in certain Finches, for instance the 

 Redpoll {AcaiitJiis linarid) and its allies, but it is not ** depig- 

 mentation " nor even " recoloration." The red color is in the 

 barbs when the feather grows in the autumn and the eye is 

 simply deceived. 



There is still another factor that modifies wear, — the habits of 

 a species or of the individual. Birds that live from morning till 

 night in the air, like the Swallows, the Flycatchers, the Vireos 

 and some of the Warblers, suffer little wear from outside sources 

 while Sparrow\s and other grass-loving species, are prone to be- 

 come exceedingly ragged in a veiy short time. No better ex- 

 amples can be cited than the Sharp-tailed Sparrow {Auitnodra- 

 iniis caudaciitiis), the Bobolink {Dolichonyx oryzivorus) and the 

 Long-billed Marsh Wren i^Cistothoriis pahistris) all of which 

 species, by clinging to harsh reeds and grasses, rapidly fray out 

 even the resistant remiges and rectrices, thus, perhaps, necessi- 

 tating two complete moults annually, although there are other 

 species, such, for instance, as the Seaside Sparrow [Aininodrainus 

 niaritiimis), which have but one, although they are apparently 

 exposed to the same amount of wear. 



The subject of wear is a large one and its possibilities are by 

 no means exhausted, although many writers have already dis- 

 cussed it most minutely, but there is need of getting beyond the 

 narrow field of a microscope focused on single parts of single 

 feathers. To base theories on pigment granules and exuding 

 pores is perhaps simpler than to prove that color and pattern 

 were present when the feather first grew and yet those who have 

 Annals N. Y. Acad. Fci., XIII, Aug. 3, 1900 — 6. 



