Vol. XIX 

 iqo2 



1 Dw'ight, Plumage-Cycles. 25I 



The second plumage of a young bird may be appropriately called 

 the Juvenal rather than 'juvenile,' which word has a less exact 

 meaning, like other terms that have been in use for this plumage. 

 The current expression ' first plumage ' is entirely inappropriate 

 for a distinctly second stage or second generation of feathers. 

 These have been called ' mesoptiles ' to distinguish them from 

 other teleoptiles but the distinction is often not very obvious, 

 although some of them in some species and all of them in others 

 are weaker and softer in structure than adult feathers, and also 

 lack, as a rule, the aduh patterns and colors. The order of their 

 growth, the types of feathers, and the areas covered, need not con- 

 cern us in the present connection, although it is important to note 

 that the remiges of the juvenal dress of land birds like the Pas- 

 seres or Gallinee, grow in advance of the body plumage, while water- 

 birds like the Pygopodes or Anatid^ acquire most of the body 

 plumage first. Among many of the smaller species of birds the 

 juvenal plumage is discarded within a few weeks. There are 

 many other species, however, both large and small that retain at 

 least a portion of it, usually the wings and tail, for an entire year. 



The postjuvenal moult is an extremely important point in every 

 plumage-cycle and varies both in its completeness and in the time 

 of its occurrence, even among closely related species. It has 

 often been confused with the prenuptial moult which in some 

 species and in some individuals it overlaps in point of time. In 

 fact, we often find this moult so long drawn out, that in some spe- 

 cies having also a prenuptial moult, both moults may be found in 

 progress on the same specimen, as may be seen among some of the 

 Longipennes, Anatidae and Passeres. But irrespective of time of 

 occurrence and extent of feather areas involved, two plumages 

 result from a postjuvenal moult, the first annual (juveno-annual) 

 or the first non-nuptial (juveno-non-nuptial) either of which may 

 be simple or compound as the moult is complete or incomplete. 

 The simple first annual plumage is illustrated by the English 

 Sparrow {Passer doincsticus) , the compound .by the American 

 Robin {Meritla migratorid) , the simple non-nuptial plumage by 

 the Horned Lark {Otocoris alpestris), the compound by the 

 Black Guillemot ( Cepphus grylle) , and there are many species in 

 many families of birds that follow one or the other of these types- 



