184 BIRDS OF TUNISIA 



RuliRistinp; as it docs aliiiusl t^ntiruly on the smaller winj^cd 

 insects, the Swallow naturally alTocts localities where such a supply of 

 food is most pKaitil'ul, and for this reason it is generally to be found 

 abundantly in the vicinity of water. The same reason, no doubt, 

 explains the fact of its presence in the busy streets of towns and 

 places teeming with life and traflic. To the greater or lesser abun- 

 dance of insect-life is also presumably due the Swallow's occurrence in 

 large numbers in certain towns and villages, while it is totally wanting 

 in others sitiuited comparatively not far distant. Of this we have 

 a very good illustration in the Sicilian towns, some of which, like 

 Trapani and Syracuse, swarm with Swallows during the summer 

 months, while others, like Palermo and Messina, have either none at 

 all or but very few during that season. It is, of course, possible that 

 there may be some other reason than that of a greater or lesser 

 abundance of food to account lor the marked preference shown by 

 this species for certain localities, but I am unable to suggest any more 

 plausible explanation. It cannot, certainly, be due to the construction 

 of the buildings, this being the same throughout the island. 



The note or twitter of this species is too well known to need 

 description. 



The Swallow breeds abundantly throughout the Kegency both 

 north and south of the Atlas, nesting operations being commenced 

 soon after the birds' arrival in spring, and two broods are generally 

 reared in a season by the same pair. The well-known nest, built 

 of mud and lined with feathers, is usually attached to the wall of 

 a building — in Tunisia as often inside as oiitsich' — and sheltered by a 

 cornice or other projection. Nests, however, are sometimes to be 

 found in clilYs and high banks, and such sites were probably originally 

 the breeding homes of this and other allied species which now resort 

 principally to human habitations and artificial walls. The eggs of 

 the Swallow, generally four or five in number, and vather elongate 

 in shape, are white, speckled wuth reddish-brown and violet-grey. 

 Average measurements 20 X 14 mm. 



As has often been proved by marking the birds, the same pair of 

 Swallows, if not parted by death, will continue to mate together, and 

 if undisturbed will return year after year to their old breeding home. 

 A2)roj)os of this, I cannot refrain from repeating here the following 

 amusing, if not altogether credible, story mentioned in Prof. Giglioli's 

 "Avifauna Italica" (p. 184), as having appeared in the Times 



