BAR-TAILED GODWIT. 257 



the adult female sanderling, which, as I have before 

 stated, is distinguishable only by dissection in some 

 instances. 



The old males evidently commence their change 

 much earlier than the young birds of the previous 

 season, as I have handled one in nearly full summer 

 plumage by the 1st of April; and the two killed on the 

 7th of May, 1866,* were very nearly as perfect as the 

 exceptionally fine male shot on the 16th. In all cases 

 the full red birds that I examined had the testes largely 

 developed, whilst the same parts in the males with 

 broken plumage were invariably small. 



The great difference in size between the male and 

 female godwits was at one time supposed to denote a 

 specific distinction,t but whilst we now know that the 

 largest are always females and the smallest males, J both 



* In the "Field" of May 26th, 1866 (p. 445), Mr. F. Hele, of Aide- 

 burgh, states that on the 14th several flights of bar-tailed godwits 

 appeared about Thorpe mere and river. Such an occurrence had 

 not been known since 1860, although a few appear every spring. 

 The difference in weight between males and females he describes 

 as remarkable; "in one case being in the male only six and a 

 half ounces, whilst the female weighed one drachm over ten and 

 a half ounces." 



f See Colonel Hawker's " Instructions to Young Sportsmen." 

 Eleventh edition, p. 232. 



J Thompson, in his " Birds of Ireland" (vol. ii., p. 229), after 

 stating that of seven birds killed at the same time on the 6th 

 of March, " the small ones proved to be males and the large ones 

 females," says "the bills of the latter, from forehead to point, 

 were from four to four and a quarter inches long," which is 

 in excess of all but one of my own specimens. He also adds, 

 " others which I have killed exceeded four and a half inches ; a 

 young bird of the year, obtained on the 24th of August, had a 

 bill only two inches in length [less than the smallest male in my 

 series]. At the end of October I once shot a godwit of little 

 more than half the ordinary weight, and hardly exceeding a grey 

 plover in size." All proving the extraordinary variation in the 

 proportions of both sexes. 

 2L 



