250 BRITISH, SEA BIRDS: 
to those found in the Fulmar—a nearly clear oil, 
mingled with the jaws of cuttlefish, and scraps of 
sorrel. 
The Fork-tailed Petrel resorts to its breeding 
stations to nest in June. Although gregarious 
during this period, its colonies are never so large 
as those of the Fulmar. Most probably the bird 
pairs for life, and returns season by season to 
certain spots to rear its young. The largest colony 
of this Petrel known to me is at St. Kilda. Here 
its principal colony is located on the island of Soay, 
but there is another and smaller one on Doon, and 
doubtless others on Borreay. At the colony on 
Doon, the ground was full of long, winding burrows, 
probably disused nesting holes of Puffins and Shear- 
waters, and in these the Fork-tailed Petrels had 
made their nests—in some cases one earth accom- 
modating several pairs of birds. Usually the 
selected burrows are in the loamy soil near the 
summit of the cliffs; but, in some cases, the birds 
will select a hole, or crevice, in ruined masonry, or 
in rocks. At the end of the burrow, or crevice, a 
scanty nest of dry grass is formed, but in some 
cases no provision whatever is made. Here the 
female deposits a single egg, white, with a zone 
of dust-like brown specks round the larger end. 
These eggs are remarkably fragile, and very chalky 
in texture. The Fork-tailed Petrel is a close sitter, 
remaining brooding over its egg until dragged out. 
oD 
Many nests may be found within an area of a few 
