751 
Spine-tailed Swift to Weather Conditions. 
April 16th.—A perfect morning, with a cloudless sky 
and a light sea breeze. Spine-tailed Swifts passed over the 
shore-scrub at a low elevation, making somewhat to the west. 
I remarked to the friend with whom I was walking, “ There 
are the Swifts, our fine weather will not last long/'’ That 
very night great cumulus clouds appeared in the eastern sky, 
drifted gradually overhead, and brought a heavy downpour 
of rain. 
April 15th.—On this day the Swifts were seen migrating, 
passing to the north-west over the beach, at a height of 
perhaps sixty or eighty feet; weather cold, showery, squally, 
wind veering north-west to south-w 7 est. 
April 27th.—-This afternoon the Swifts passed to the 
north-west in a long straggling party, over the beach and 
the sea, at a height of perhaps sixty feet; wind south-westerly, 
strong, cold. This was their last appearance, and the latest 
date at which I have ever seen them ; I believe it constitutes 
a record for Tasmania, and probably for Australasia. 
A reason may now be suggested for these appearances of 
the Swift in the time of disturbed weather, and it is this. 
The bird feeds largely upon ants in the winged state, and, 
indeed, I believe such to be its favourite article of food; the 
male and female ants having reached the winged state, fre¬ 
quently issue in vast numbers from their nests during those 
hot muggy days which precede a disturbance, w 7 hile the so- 
called u white ants** or termites, very tasty morsels, will often 
“ swarm ” while a light warm rain is actually falling. It 
seems highly probable, therefore, that this Swift appears in 
numbers in the vicinity of a weather-disturbance because its 
favourite food is more plentiful and more easily obtained at 
such times. There may be other conditions of which at 
present we know nothing, affecting the sudden appearances 
and disappearances of this most interesting species, but the 
theory here advanced seems a reasonable one. I hope, 
however, that other observers of. our migratory birds may 
be induced to give particular attention to the habits of this- 
fine Swuft. 
