Demeanour when Nesting 403 
by a well-timed swoop easily dislodge a man from any dangerous 
ledge, where both hand-hold and foot-hold are alike uncertain, 
only the fact remains that they never think of such a_ thing. 
Those who have not penetrated into their haunts can_ hardly 
imagine the loud rustling sound they produce by their movement 
through the air as they approach their nests. At times when | 
have been safely ensconced at the back of some cavern on the 
face of a cliff waiting for the chance of a photograph, the Griffons 
which had been sailing around high above the cliff, emboldened 
at seeing nobody about, have come swooping down to inspect 
their nests with a noise which can best be likened to a powerful 
steam-blast ; this, heard for the first time, is decidedly startling. 
Sometimes when | have been climbing along the face of a crag 
a Griffon has suddenly rounded a corner of the cliff, gliding within 
a few feet of me with outspread and apparently motionless wings, 
its fierce looking head and eye bent inquiringly towards me. But 
the instant it detected my presence, it would heel over in its flight, 
and by a few strokes showing extraordinary strength sweep upwards 
and away. 
On one and one only of my many scores of visits to Griffons’ 
nests did one of these birds even attempt to oppose my approach. 
This was in 1907; I was working along the ledges of a tall cliff 
when | heard a loud hissing sound which was repeated again and 
again. On rounding a crag, I saw an adult Griffon standing up 
over her nest which contained an egg, not 15 ft. from me. So 
long as I stood still the great bird continued to strike a_ series 
of threatening attitudes, at intervals emitting a loud hissing sound 
much resembling an escape of steam. She was very loth to quit 
her egg and every time I made as if to depart, she subsided on 
it and recommenced sitting, only to rise again and hiss savagely 
when I returned towards her. I got out my camera and photo- 
graphed her in one of these positions, but regret that owing to 
