21 



to hold the egg firmly, and yet without risk of 

 damaging the tender shell. On the other hand 

 other observers state that the egg is conveyed to the 

 nest by the claws. It is interesting to note that the 

 egg may be a good match in colour, with those of the 

 foster parents. This may have been brought about 

 by natural selection, as probably each individual 

 cuckoo always chooses the nest of the same species 

 for all her eggs. 



Case 161. — The young Cuckoo is here seen occupying the nest of 

 (a) the Hedge Sparrow, and (6) the Wagtail. In 

 both instances the foster-mothers are shown convey- 

 ing food to the usurper. 



Case 162. 



SEDGE-WARBLER {Acrocephalus phragmitis). 

 Local name : Water Nanny. 



A common summer visitor, generally distributed over the British 

 Islands from the latter half of April till the end of September. It 

 frequents meres and reedy swamps, and the nest is generally placed 

 in a low bush or among rank herbage by the side of some stream or 

 ditch. It is composed of moss and coarse grass, and the inside is deep 

 and thickly lined with hair. The eggs, four to six in number, are of 

 a pale yellowish-brown, generally suffused or sometimes slightly mottled 

 with darker brown, and not unfrequently streaked with hair-like 

 lines of black (see British Bird Egg Cabinet, drawer 2). They are 

 generally laid towards the end of May and hatched in June. 



Case 163. 



BLACKCAP {Sylvia atricapilla). 



A common summer immigrant, arriving about the middle of April, 

 and departing southward in September, a few birds occasionally staying 

 throughout the year. It frequents woods, thick hedges, orchards and 

 gardens. Its song is frequently mistaken for the Nightingale. The 

 nest, built of dry grasses and lined with horsehair, is usually fixed in 

 a bush from two to five feet from the ground. The eggs, five to six 

 in number, dift'er much in colour, and are usually yellowish-brown 

 blotched with darker brown, but sometimes both ground colour 

 and markings are of a reddish hue (see British Bird Egg Cabinet, 

 drawer 2). The eggs are laid first about the middle of May, and two 

 broods are reared in a season. 



