GREAT BLACK-HEADED GULL. 301 



flat or grassy slope of these islets, never on the 

 precipitous part of the cliff, the eggs almost laid 

 on the ground, or with a small portion of dried 

 grass collected. Mr. Dunn writes, in Orkney and 

 Shetland the Black-backed Gull " builds its nest on 

 small islands on stalks and the most inaccessible part 

 of the rocks/' The parent birds defend their nest 

 from all winged aggressors, but on the more fre- 

 quented islands they seem to dread more the pre- 

 sence of man, and soar high over head, showing 

 their anxiety by their continued hoarse cackle, and 

 only occasionally venturing a stoop at the ag- 

 gressor. 



A specimen shot in the Firth of Forth in Fe- 

 bruary, and sent for our use by Mr. Fenton of 

 Edinburgh, is in length between twenty-six and 

 'twenty-seven inches;* the extent of the wings, 

 fully expanded, five feet; the whole of the bead, 

 neck, rump, tail, under wing-covers, axillary fea- 

 thers, and all the under parts of the body, pure 

 white ; the centre of the back and mantle deep 

 greyish black, the quills nearly black ; the second- 

 aries are tipped with white, forming a bar across 

 the wing; the first quill is tipped with white for 

 nearly two inches, the second for a shorter space, 

 but having a narrow black bar interrupting it near 

 the tip; the third with a short white tip, and the 

 fourth with a short white tip succeeded by black, 

 again succeeded by a narrow clouded bar of greyish 



* Mr. Yarrell gives the male as thirty inches, the femala 

 as twenty-seven. 



