112 BIRDS OF THE COUNTRYSIDE 



free both from the fowler who kills and the keeper 

 who cripples, and so a distinction to my neighbour- 

 hood in proportion as it is better to receive and 

 enjoy the gift as it comes than to compel and spoil 

 it. When disturbed, they took flight, beating along 

 the water like moorhens, except that they did not 

 touch it and frequently taking extended flights, 

 descending to water with a rush of wings. In the 

 water they look stout and thickset of build, their 

 bright yellow irides sparkling from their purple-black 

 heads vdth pendant crests, and the stretch of dead 

 white on the flanks, very different from the glowing 

 sheen of the big grebe's breast, lower breast and 

 belly rimming the violet glossed black of the backs 

 rather in the shape of an Indian canoe. They used 

 to dive and bring up their meals from the bottom to eat 

 comfortably on the surface, and thereby hangs a tale. 



The tufted ducks fed at various times of the day, 

 and I noticed that Larus ridibundus invariably called 

 upon them at meal-time. To my delight, I discovered 

 that this gull, taking a leaf out of his cousin, the 

 skua's, book, had established a definite, formal and 

 orderly parasitic relationship with the duck he gulled. One 

 day ninety-six tufted ducks were attended by some thirty 

 gulls, and as soon as one of the former went down, 

 a gull placed himself in the neighbourhood. The duck 

 reappeared, and the gull (sometimes a pair of them) 

 left the water, hovered a yard or two above the duck's 

 back, and swooped gently down upon the innocent. 

 Down went the duck again, dropping his food on the 

 surface, the gull half submerging to recover it. The 

 stoop was obviously made with the intention of 

 flustering the duck, a stratagem successful nine times 

 out of ten. The same process took place with the 

 other gulls and day after day. The experimental 

 stage was long past, and yet I believe I have the 

 honour of being the first to record this secret. The 

 food of the duck was neither weed nor fish on the 

 occasions I watched this ingenuity, but so far as I 

 could guess, water-snails (Limnea), limpets {Ancylus), 

 and other freshwater molluscs. 



