BRITISnDIRDS 



EDITED BY H. F. WITHERBV, F.Z.S., M.B.O.U. 

 ASSISTED BY W. P. PYCRAFT, A.L.S., M.B.O.U. 



Contents of Number 12. May 1, 1908. 



On the Development of a Young Cuckoo, by P. H. 



Bahr, m.a., f.z.s., m.b.o.u. . . . . - . • . Page 361 



Some Observations on the Song-Periods of Birds, by C. J. 



and H. G. Alexander . . . . . . . . . . 367 



The Nest of the Ringed Plover, and tlie Bearing thereof on 

 tlie Evolution of Birds' Nests in General, by W. P. 

 Pycraft 373 



Notes :— The Birds of Fair Isle (H. F. W.). Melanism in 

 the Coal-Titmouse (Percy F. Bunyard). Crossbill 

 Nesting in Northumberland (J. S. T. Walton). An Old 

 Record of the Little Bunting in Essex (H. E. Dresser). 

 Migration of Hooded Crows (C. J. Alexander). Supposed 

 Black Woodpecker in Nottinghamshire (J. Whitaker). 

 Stock-Doves Nesting on Lincoln Minster (F. L. 

 Blathwayt), etc., etc. . . . . . . . . . . 381 



Review : — A Monograph of the Petrels (Order Tuhinarc.s) . . 390 



Letter :— Wounded Peregrine Fed by its Mate (P. H. Bahr) 392 



ON THE DEVELOPMENT OF A YOUNG 

 CUCKOO. 



BY 

 P. H. BAHR, M.A., F.Z.S., M.B.O.U. 



The subject of the accompanying- illustrations was hatched 

 on June 20th last year, in a Pied Wagtail's nest, situated 

 quite close to the house, in a privet hedge, on the border 

 of a path where gardeners were constantly passing and 

 repassing all day long. This was the third consecutive 

 year in which this j)articular pair of Wagtails had been 

 so duped. 



The young Cuckoo did not hatch till the young 

 Wagtails, three in number, were three days old. But 



