Vol. XVII 



I go I 



n General Notes. 2O3 



Notes on the Moulting of Spinus pinus and of Hirundo erythrogaster. 

 — In the January ' Auk,' Mr. Stone has so pleasantly reviewed my paper 

 on ' The Plumages and Moults of the Passerine Birds of New York,' that 

 it is evident we are in complete accord as to the facts and conclusions 

 which we have each reached working along independent lines. There 

 are, however, two species, the Pine Finch and the Barn Swallow, about 

 which there is yet a word to be said. Mr. Stone appears to be correct in 

 claiming a prenuptial moult in the Pine Finch, but it is ordinarily so 

 extremely limited that I considered it as the irregular renewal, found in 

 spring in so many species, which scarcely deserves the name of a distinct 

 moult. Two of Mr. Stone's Pennsylvania birds taken in May show more 

 evidence of growth of new feathers about the head and throat, and even 

 of new tertiaries, than I would have suspected from the other mate- 

 rial I have studied. The re-examination of nearly 150 specimens, taken 

 every month in the year, shows that birds of April, May and June are 

 exceedingly worn. Among seven April and eleven May specimens, I 

 find so little evidence of the growth of a few new feathers, and onh' on 

 tlie throat, that Mr. Stone's specimens which I have examined are indeed 

 a surprise to me, and suggest unusual precocity. As, however, this 

 species is subject to a considerable amount of wear, it is probable that it 

 belongs with those species having a very liinited first prenuptial moult 

 which is not repeated a second year, and the wear, quickly affecting the 

 new feathers, obliterates evidences of moult. 



Mr. Stone and I do not quite agree about the Barn Swallow (^Hirundo 

 erythrogaster)., for he speaks of an "apparent prenuptial moult," basing 

 his opinion on a bird (Phila. Acad. Nat. Sci. No. 2S576, September 1, 

 Pennsylvania), which he considers an adult after the postnuptial moult, 

 and therefore requiring a prenuptial moult to produce the attenuated 

 lateral rectrices of the breeding bird. The specimen in question has been 

 kindly loaned to me, and I am satisfied it is a young bird in fresh juvenal 

 plumage, for the slight forking of the tail and the green tinge of the back 

 with reddish-brown edgings on the rump, nape and wing-coverts are char- 

 acteristic of a dozen other young birds in my own collection. The green 

 tinge, by the way, is peculiar to the young of all our Swallows, and of 

 other birds with iridescent feathers, like Crows and Blackbirds, in which 

 adults are usually bluer or purpler than young birds. Here is a case 

 where immaturity might be shown by softening the skin and examining 

 the ossification of the skull. 



Three other interesting Barn Swallows have been sent to me by Mr. 

 Stone. Two of them have already been noticed in his valuable paper on 

 moult, and I agree with him that two of them (Phila. Acad. Nat, Sci., No. 

 28574, August 7, Pennsylvania, and No. 2S577, September i, Pennsyl- 

 vania), are adults just beginning the postnuptial moult, which, doubtless, 

 would have been completed after they had reached winter quarters, or 

 perhaps while on the journey thither. The same sort of feather renewal 

 takes place among some of the Tyrannidre, Laridse, Limicolje and others 



