Vol. XXVIII 

 1911 



J Townsend, Courtship of the Red-breasted Merganser. 345 



the fall, while in the spring their ranks again increase but never 

 equal the multitudes of the fall. 



The explanation of all this is interesting and I believe sufficiently 

 apparent. The great flocks of birds in the fall in somber plumage 

 are made up of immature birds, of adult females, and of the adult 

 males in the eclipse plumage. In November the adult males moult 

 into the nuptial plumage, while the females and young leave for 

 the south, so that during the winter months practically all the birds 

 are adult males in full plumage. Whether the exceptions are 

 females or immature males or both I cannot say. In March and 

 April the females return from the south as well as the immature 

 males, which have not moulted into adult plumage, together with 

 some adult males. 



The southern side of this picture which rounds out and corrobo- 

 rates my northern observations has been given me by Mr. Wm. 

 Brewster who said that in Florida in winter he had seen large 

 flocks of female and immature Red-breasted Mergansers, and by 

 Mr. Arthur T. Wayne, who, in his ' Birds of South Carolina,' 1910, 

 page 13, says of this species: "From the time when these fish- 

 eating ducks arrive until the first week in February the adult, 

 drakes are seldom, if ever, seen, but towards the second week in 

 February they make their appearance in large numbers." 



The old males brave the rigors of the northern climate, while 

 the females and young seek warmer regions during the winter, but 

 it would seem as if some of the impatient suitors were unable to 

 await the return of their partners from the south, and must needs 

 go and fetch them- 



