ON THE MOULTING OF THE HERRING GULL 103 



the end of June though scarce in April and May as they 

 were at any time later on. The numbers of adult Herring 

 Gulls diminished during May, and in June very few were 

 present, but early in July they began to reappear in 

 numbers. This seems to dispose of the objection that 

 the apparent difference in season of the younger and older 

 birds' moults might be due simply to the absence of the 

 latter at their breeding-places during the earlier part of the 

 period. 



It would be interesting to follow this up as having, 

 possibly, some bearing on the evolution of the present-day 

 larine type. An investigation of the moult of the Limicoke 

 might possibly produce some facts of importance with regard 

 to the hypothetical evolution of the two groups from a 

 common stock. 



It may be suggested that among the Gulls, the adult 

 birds moult later, because moulting would be inconvenient at 

 the time of rearing young; but, then, why do not the 

 immature stages moult at the later season also ? Which is 

 the ancestral method ? 



Secondly, I have to record a few observations on the 

 ORDER OF MOULTING of the feathers of different tracts of 

 the body, in the Herring Gull and the Kittiwake. 



Little appears to be known as to the order of moulting 

 of the body-feathers in any group of birds, and not much 

 more as to that of the wing- and tail-feathers. 1 The follow- 

 ing notes, derived from the examination of wild birds found 

 dead during the moulting season, may therefore be of value. 

 The method employed was simply to note the condition of 

 the feathers in the various parts of the body, and the relative 

 numbers of old, and incomplete, or fully-developed new 

 feathers. 



I. Herring Gull. The primaries are moulted in pairs, the 

 innermost first, each one dropping when the new feather to replace 

 the next-previously dropped feather is beginning to sprout, so that 

 only two pairs of primaries are unserviceable at a time. 



1 W. P. Pycraft : A History of Birds, 1910, p. 282. 



