{ 14t) ) 

 THE BLACK-NECKED GREBE. 



BY 



OLIVER G. PIKE, f.z.s., f.r.p.s. 

 (Plates 3 to 10.) 



Most ornithologists and egg-collectors know that the Black- 

 necked Grebe [Podiceps n. nigricollis) nested on the Tring 

 Reservoirs (Herts.), last year, so I am giving away no secrets 

 when 1 say that my photographs and notes were obtaired 

 there. Personally, I am sorry that the haunt was mentioned, 

 as a number of egg-collectors endea voured to take the eggs this 

 year. One company of four men made a desperate effort to 

 obtain the eggs, and waded out to the nest a distance of over 

 one hundred yards, through a most treacherous reed-bed, 

 using the " hide " I had erected near the nest as a guide, but 

 foitunately a Dabchick had its nest close to that of the Black- 

 necked Grebe, and when the men arrived at my hide they were 

 evidently in too great a hurry to look around, for they 

 failed to see the nest of the Black-necked Grebe, and went off 

 with the clutch of Dabchick's eggs, no doubt thinking that 

 they had the eggs of the former bird ! 



My notes are confined to the birds on Marsworth reservoir, 

 as I did not have time in the n casting season to watch those on 

 the other reservoirs. Four birds arrived on May loth, 1919, 

 and in the evening the males were fighting desperately, while 

 the two females kept at a distance of about twenty yards and 

 watched the fight. One male was very aggressive, and 

 followed the other. The battle for a time was most violent, 

 the birds falling over one another in the water, dashing at 

 each other and diving. I watched this for about an hour. 

 The next morning there was only one pair on this reservoir, 

 so I came to the conclusion that the pair that had nested here 

 last year had returned, and also succeeded in driving off 

 another pair that wished to remain on the reservoir. I had 

 seen two pairs on Wilstone Reservoir on the loth also, and as 

 I could only see the two pairs there on the nth, the second 

 pair from Marsworth were evidently the pair that arrived 

 about that date on a more distant reservoir. 



