MOUSE -COLOUBEB SWIFT. 83 



'^I have been for some time convinced that tlie Common Swift of 

 Egyyt forms an entirely distinct species from the well-known C. apus, 

 under which name it has been included in the various lists of Egyptian 

 birds. First it differs materially in the very pale brown of the entire 

 body, and in the greater extent of the white on the throat. These 

 constitute the most striking characters whereby it may be distinguished 

 from C. apus. Furthermore the feet are smaller; indeed the bird is 

 altogether smaller in bulk. 



"I believe that C. apus seldom appears in Egypt. I could never 

 detail a dark specimen, though I paid particular attention to the species, 

 in order to confute the opinion of several naturalists at home, who 

 were inclined to consider the Egyptian species identical with C. apus. 

 If therefore I saw any bird out of the hundreds flying about me, 

 which appeared to be a trifle darker than ordinary, I immediately shot 

 it; but on every occasion the bird thus obtained turned out to be C. 

 pallidus. 



"Again several ornithologists were inclined at first to put down any 

 Egyptian specimen as the young of C apus ; but it is impossible for 

 that opinion to be correct, since T have shot C. 'pallidus as late as 

 the 3rd. of May, and as early as the 12th. of February. Comparing 

 my specimens with the young of C. apus, the colour of the latter is 

 very much darker, and all the feathers have distinct white margins." 



Lieutenant-Colonel Irby, in his recent work upon the ornithology 

 of the Straits of Gibraltar, throws further light upon this bird, which 

 he calls the "Mouse-coloured Swift," in which I have followed him, 

 as it is always advisable in naming birds to adopt some peculiarity 

 which they possess. He says, "This Swift is found near Tangier on 

 passage, crossing to Europe in April and May. Some remain to breed; 

 but it is the least common of the family, being seen alone or in pairs 

 in company with C. apus, which circumstance makes it diflicult to dis- 

 tinguish them. I found a pair in July, 1861, nesting in company 

 with some House Martins; the nest was simply an old nest of that 

 Martin, which the Swifts had appropriated, and contained two eggs 

 of the usual Cypselus shape, their longitudinal circumference being 

 64.66 millemctres." — Favier. 



"Though Favier says they are diflicult to distinguish from the 

 Common Swift, I cannot say so myself, but rather the contrary. They 

 are occasionally seen near Gibraltar, and are said to arrive at Tangier 

 somewhat earlier than the Common Swift, though I could see no 

 difference in the time of their arrivals. Easily noticed on the wing 

 by their light colour, they mix both with the Common and White- 

 bellied Swifts. 



