130 BIRD LIFE ON ISLAND AND SHORE 
the joyous call of Swifts over some grey, old-world 
cathedral town screaming as they fly, Mutton 
bird gatherings are perfectly still. There is about 
them the fascination of speed without effort or 
apparent driving power. As evening progresses, 
the more venturesome begin to drop on to the 
ground through the trees from above, or skimming 
direct on to the naked sides of the island, reach 
land on the run, fast flyers sometimes in alighting 
seeming almost to ricochet along the surface. 
These different ways of arrival may perhaps be 
ascribed to a change in the vegetation of the 
islands of the south, a change perhaps from a 
vegetative covering of grasses and sedge only to 
a later type of growth, one such as now clothes 
the surface—scrub of fifteen and twenty feet. 
The method still practised by the majority of 
Mutton birds is the direct drop; the other—the 
later mode,—that of alightment about the cliff 
edges and progression centrewards, is followed by 
comparatively few. Those constant to what we 
may believe to be the old fashion, if haply not 
tangled on the twiggy tops, fall plump and solid 
with folded pinions. Should, however, a Petrel 
be caught on the tops—and it happens to scores 
of birds nightly,—no sign of terror is shown; it 
rests on the tupari-tops apparently indifferent 
for minutes together. No mortal astonishment or 
uneasiness is evinced, even though it may be 
