I 



PASSERINE BIRDS OF NEW YORK 115 



this. It seems to be true of the average adult, yet many young 

 birds either at the postjuvenal, the first prenuptial, or the first 

 postnuptial moult do assume colors quite as bright as the most 

 highly colored adults. 



It seems probable that females which assume male plumage 

 contrary to their usual habit are old adults. The most difficult 

 problem to solv^e in connection with this stage is whether all adults 

 continue to have a prenuptial moult after the first year. There 

 are few species which do not show renewal of a few scattering 

 feathers, chiefly noticeable on the ramal margins of the chin, at 

 the season of the prenuptial moult and perhaps as we learn 

 more of it we may be obliged to consider this moult universal 

 and merely suppressed in certain species just as it is in the fe- 

 males of certain species. We can easily tell how extensive it is 

 in young birds from differences of plumage, but with adults it 

 is difficult, for many of them assume a winter plumage that 

 wear alone might easily convert into the nuptial dress. A mere 

 sprinkling of new red feathers among the yellow ones of the 

 young Summer Tanager {Piranga rubra) for instance, is con- 

 spicuous, but the same sprinkling might occur a second season 

 and be quite overlooked among the old red ones especially 

 when wear has assailed both sorts. When the prenuptial moult 

 is fairly extensive, old tell-tale feathers show that both young 

 and old undergo a moult, but when it is limited to small areas 

 and to few feathers the problem is anything but easy even with 

 specimens actually in process of moult. With specimens taken 

 long after the prenuptial moult it may be impossible to make out 

 from the amount of wear whether the feathers of the perhaps 

 identical winter plumage have been I'enewed or not. If all the 

 spring specimens of a species show evidences of moult, it is fair 

 to assume that both adults and young have been affected. In 

 spite of the evidence pro and con I must admit the question of 

 the adult prenuptial moult is one that in a number of species 

 has not been settled to my entire satisfaction. If young and old 

 could be told apart in all cases at this season the matter would 

 be much simplified. It depends now chiefly upon knowledge 

 of winter plumages and estimates of wear. 



