CYPSELUS APUS 25 



by the Pallid Swift, but later and more careful observations have 

 proved this supposition to be wrong. On the contrary, as I have 

 already stated above, many of these Swifts breed in Tunisia, and out 

 of a large series of specimens of the two species, which were sent me 

 from Tunis in the month of June, fully half of the birds proved to be 

 of the present species. 



In the choice of its summer quarters the Swift evinces a marked 

 preference for certain localities, and like the common Swallow, may 

 be found abundant in one spot, and entirely absent in another close 

 by, which apparently offers the same attractions of food and environ- 

 ment. In Sicily, the Swift is to be found in summer in vast numbers 

 in some of the towns on the west and south-west coast, but is totally 

 absent from many others, where one might expect it to be equally 

 abundant. 



As already mentioned, C. apus reaches Tunisia in spring about the 

 end of March, but occasionally a few of the birds may be seen before 

 that date, particularly in the more southern districts. At Kairouan 

 I have found the species, together with C. murlnus, at the beginning 

 of April, in certain numbers, hawking for insects around the Great 

 Mosque of Sidi-Okba. Mr. Aplin, when collecting in Tunisia in 1895, 

 found both species in large numbers at Kairouan and at El-Djem 

 towards the end of April, and wrote to me regarding the birds as 

 follows : — 



" In an old disused Mosque court-yard at Kairouan, I saw C. apus 

 enter a hole in the roof. At the big Mosque I saw Swifts more 

 numerous by far than at any other place I have been in. Many were 

 about the town, but most were collected here. As I stood on the 

 tower, a perfect swarm, like bees, were in the air around me, and as 

 I looked down on the dazzling white court, it seemed full of them, 

 darting about, low down over the hot pavement. On the tower the 

 birds passed close to me, and I had a very good opportunity of 

 observing them. C. apus was present, but by far the greater number 

 were C. pallidus, looking on the wing, almost as brown as C. melba, 

 and as they pass close above you, the large extent of white throat is 

 apparent. The cry of C. pallidus is a little different from that of 

 C. apus, being less resonant, and like ' stvee-a,' or simply ' swee,' 

 One or two AVhite-rumped Swifts were among the swarm, chubby 

 looking little birds, but without the dash of the bigger birds." 



Mr. Aplin again met with Swifts in the wooded districts of North 



