118 BIRDS OF NORFOLK. 
not unfrequently seen consorting with dunlins, but when 
in small or large flocks they invariably feed by them- 
selves. 
With the sanderling, as with the knots and god- 
wits, it is only by comparing a large number of birds 
killed at different dates, and of which the sex in each 
instance has been accurately ascertained by dissection, 
that one can arrive at any satisfactory conclusion 
as to the change of plumage from the winter to the 
summer dress, or the differences observable between 
males and females. It was with this view that I collected 
specimens at Hunstanton in 1863, whenever opportunity 
offered, between the 19th of May and the 8th of June, 
and an examination of this very beautiful series of skins, 
fourteen in number, presents many points of interest. 
From the late period of my visit, of course even 
the earliest birds procured had nearly completed their 
change of plumage, but it is remarkable that, in both 
sexes, one or two examples killed in the middle of May 
were as perfect and as rich in colour as any I obtained in 
June, a circumstance which I have since observed, at 
the same season, in the bar-tailed godwits (Limosa rufa), 
and from which I infer that very old birds or those 
of extremely vigorous constitutions acquire thei full 
summer dress sooner than others. This is particularly 
noticeable in a male and female both shot on the 26th 
of May, the male being by far the darkest bird in the 
collection, and the female showing quite as much red 
on the fore part of the throat and neck as in any of the 
males killed in June. Two other females shot on the 
same day, young birds most probably of the previous 
year, are in the prettiest state of change possible, the 
upper portions of their plumage mottled with red, white, 
and black, with here and there a feather still pure grey, 
and their throats sprinkled with dark spots on a white 
ground, with scarcely a tinge of red yet visible. Again, 
