SIX MONTHS’ BIRD COLLECTING IN EGYPT. 203 
subject appear to require further elucidation.* They do 
not appear to have got it, as I cannot lay my hand on any 
work which explains why two adult black-backed males, shot 
in the spring, should have, the one a dark-brown head and 
neck, and the other those parts white; but it is so in two of 
my Egyptian skins. I shot eight or nine Stilts, and I took 
some pains to unravel the mystery of their plumage, but all 
T could ascertain was that the black-backed ones were never 
females, though the brown-backed ones might occasionally 
be males. Perhaps the white head is the summer plumage.t 
Mr. Blyth has some remarks on the colour of their heads in 
“The Ibis” (1865, p. 35), and he concludes by saying that 
the most likely explanation is “that differentiated races of 
this bird have been more or less commingled.” This is 
probable, but not satisfactory. 
The skin of the leg is scurfy, and the colour varies, the 
lightest birds having the lightest legs. The tarsus in the 
male is longer than in the female. 
166. COLLARED PRATINCOLE, Glareola pratincola 
(Linn.); “Abou El Rusr.” 
Generally in flocks, but occasionally solitary. First shot 
on the 2nd of April. All naturalists have found a difficulty 
in saying to what family these birds belong. In their cry, 
flight, etc, I think they more resemble Terns than any 
other birds, and they are more often seen on a sandbank 
than inland. Four shot on the oth of June out of a large 
flock had beetles in their crops with red backs and a peculiar 
smell. Their being in a flock looked as if they were not 
breeding. 
* Vide Gurney and Fisher in “ Zoologist” for 1846, p. 33. 
+ Against this view 1 must remark that Canon Tristram has a black- 
headed specimen, shot by himself in Algeria in June, and he informs 
me that others killed at the same time were black-headed also. 
