BY H. STUaKT dove, F.Z.S. 101 



April 27th. — This afternoon tne Swifts passed to the 

 north-west in a long, straggling party over tne beach and 

 the sea, at a height of perhaps 60 feet; wind south-west, 

 strong, cold. This was their last appearance, and tlie 

 latest date I have ever seen them ; I believe it constitutes 

 a record for Tasmania, if not for the Commonwealth. 



Now, the Spine-tailed Swift is very fond of ants in the 

 winged state, and these insects constitute a large portion 

 of its food while with us : I have noticed that the male and 

 female ants of various species attain the winged state, and 

 "swaiTii," or issue, in vast numbers from the nest, generally 

 during the moist, muggy weather which Drecedes an atmos- 

 pheric disturbance ; the termites, or so-called "White ants," 

 will often swann during a light, warm rain. It has, there- 

 fore, occurred to me that the frequent appearance of the 

 Spine-tail Swift either during, or shortly before or after, 

 disturbed ntinospheric conditions, may be due to its winged 

 food occurring more plentifully at these 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, and I shall be glad if it is the 

 means of inducing other observers of ottr migratorv fauna 

 to give particular attention to the habits of this swift. 



