Notes on the Plumage of North American Birds 



263 



inch longer than the central ones. However, they seem to answer all the 

 requirements of successful aerial navigation. Not only are the young birds' 

 first flights made with evident ease and precision, but, contrary to the rule 

 among passerine birds, they migrate to winter quarters before changing this 

 nestling plumage for their first winter dress. For this reason we do not yet 

 know exactly when the postjuvenal molt occurs, nor do we know whether 

 there is a spring or prenuptial molt. 



Dwight records specimens from South America which were completing 

 their molt in February, but whether it was a postjuvenal or prenuptial molt 

 cannot be determined. 



A specimen taken at Corumba in southwestern Brazil, March 23, is in 

 fresh plumage and has evidently just completed a molt, but no traces of the 

 preceding plumage remain, and one cannot therefore say whether it was that 

 of the adult or of the immature bird. 



A specimen taken December 19 at Juntas de Tamana in western Colombia, 

 still wears the nestling plumage. It is not conceivable that this bird would 

 have both a postjuvenal and prenuptial molt before returning to us in its 

 breeding dress, and it therefore indicates that the young bird, at least, molts 

 only once after leaving us, and that at this molt it acquires the plumage of 

 the adult. 



BRONZED CRACKLE 

 Photographed by H. and E. Pittman, in Manitoba 



