168 UIRD GALLEKY. 



chestnut on the sides of the head and neck is replaced by rufous white, 

 the crown is brown, and the underparts of the body much paler. 



Norfolk, May. 

 Presented by Lord WaJsingham. 



No. 86. CUCKOO. (Cuculus canorus.) 



This well-known visitor to the British Islands is generally distributed 

 over Europe and Northern Asia during the summer months, arriving 

 in the south of England about the first week in April and remaining till 

 August or sometimes later. The food consists of insects and their 

 larvse, especially hairy caterpillars. The parasitic habits of this bird are 

 well known ; it builds no nest, and the female Cuckoo lays her egg on 

 the ground, conveying it in her bill to the nest of the foster-parent. The 

 Hedge-Sparrow, Wagtail, Meadow-Pipit, Sedge- Warbler, and Reed- 

 Warbler are the hosts generally selected, but the nests of many other 

 species are less frequently made use of. Soon after the young bird is 

 hatched it ejects the other nestlings, and when two young cuckoos 

 occupy the same nest the struggle for existence is sometimes severe. 

 Erom four to eight eggs are laid in a season and the period of incuba- 

 tion lasts for twelve or thirteen days. The eggs laid by different 

 individuals vary greatly in colour, sometimes resembling those of the 

 foster-parent ; pale blue eggs are occasionally found like those of the 

 Hedge-Sparrow and Redstart, but are not invariably placed in nests of 



these birds. 



Norfolk, June. 



Presented by Lord Walsingham. 



No. 87. SWIFT. (Cypselus apus.) 



This common summer visitor to the British Islands arrives towards 

 the end of April and remains till the end of August, when the majority 

 depart southward to their winter-quarters, though individuals some- 

 times remain till much later in the year. The food consists entirely of 

 insects, taken on the wing in the course of the bird's extraordinarily 

 rapid flight. The nest, a slight structure of straws, cobwebs and a few 

 feathers, is placed under the eaves of buildings, in crevices of cliffs, or 

 even in hollow trees. Two oval white eggs are laid in the end of May 

 or early in June and incubation lasts for eighteen days. As a rule, only 

 one brood is produced in a season. 



Forfar. Eggs, 6th June: young, 2nd and 20th July. 

 Presented by Dr. Thomas Dewar. 



