748 
Mr. H. S. Dove on the Relation of the 
XXX.— On the Relation of the Spine-tailed Sivtft (Chsetura 
caudacuta) to Weather Conditions in Victoria and Tasmania . 
By H. Stuart Dove, F.Z.S., M.R.A.Q.U, 
During a stay among the mountains of Northern 
Tasmania I used to notice that the Spine-tailed Swift usually 
appeared in connexion with an atmospheric disturbance; 
and observations since carried out both in Victoria and 
Tasmania appear to fully confirm my idea that this species 
finds something attractive in that part of a country w T here 
an alteration in the w r eatheris either pending, has just taken 
place, or is actually in progress. It may be well to state, 
first, that this fine Swift comes down south from China and 
Japan, and, after spending the summer months with us, 
departs again for the north in the autumn. There is great 
variation in the numbers which annually visit us, for during 
some seasons scarcely any are seen, while during others, 
such as the summer recently past (which has, by the way, 
been a remarkably unsettled one), the Swifts are seen in 
such numbers as absolutely to force themselves upon our 
attention. 
I have recorded a number of appearances, both during the 
summer of 1909-10 and that of 1910-11, and will now give 
these in sequence as they were written down. 
During the summer first named, that of 1909-10, which 
was much more settled than that wdiich has just left us, I 
w r as residing in the island State of Tasmania, and saw no 
Swifts at all until March 4th, 1910, when a solitary specimen 
was sighted; on the 8th of the same month a small party of the 
Spine-tails was seen near the beach at West Devonport, North- 
West Tasmania, where insects w r ere plentiful in the warm 
humid atmosphere w T hich prevailed after the heavy rains of 
the previous day and night. Before this, we had enjoyed a 
long spell of hot w eather, during which none of the birds 
were observed; thus it will be noticed that as soon as a 
change in the atmosphere occurred the Swifts were quick to 
respond. Of this party at the coast, some swooped along 
near the ground, others high up ; they often turned 
