7-18 jNIr. II. S. Duvc on t/te Rclution of the 



XXX. — On the Relatio7i of the Spine-tailed Sivift (Clioetnra 

 caudacuta) to Weather Conditions in Victoria and Tasmania. 

 By H. Stuart Dove, F.Z.S., M.R.A.O.U. 



During a stay among the mountains of Nortliern 

 Tasmania I used to notice tliat 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 where 

 an alteration in the weather is either pending, has just taken 

 ))lace, or is actvially in ])rogress. It may be well to state, 

 first, that this fine Swift comes down south from China and 

 JapaUj and, after spending the summer months with us, 

 dcjjarts 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 

 Avas much more settled than that Avhich has just left us, I 

 was residing in the island State of Tasmania, and saw no 

 Swifts at all until March 4th, 1910, when a solitary specimen 

 Avas 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, Avhere insects were plentiful in the warm 

 humid atmosphere which prcA^ailed after the heavy rains of 

 the previous day and night. Before this, we had enjoyed a 

 long spell of hot weather, during which none of the birds 

 Avere 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 



