378 THE ZOOLOGIST 



of the nesting area is the poverty it shows of aniimil food. 

 The normal hatching of the chicks coincides with the presence 

 of large numbers of Stonefly nymphs under the stones at the 

 water's edge. These nymphs are fed extensively to the young 

 soon after they leave the nest. Beyond this the breeding area 

 contributes little or nothing to the feeding of the young, and the 

 need is insistent for an additional 'area capable of supplying 

 the food required. In all the occupied areas the shingle or mud 

 stands high enough to be above the probable level of spring and 

 summer floods. It matters little for the young, but it may be 

 serious enough for the eggs. Evidence is not awanting to show 

 that the nesting activities in relation to water level are adjusted 

 to the normal breeding time only. When a second laying 

 becomes necessary, adjustment is not so accurate. 



On the shingle nesting and the rearing of young are confined 

 to those parts where the stones are not larger than the eggs. 

 The stones may, however, be much smaller — little more indeed 

 than fine gravel— without preventing nests being formed and 

 eggs laid. But wherever the stones are considerably larger than 

 the eggs nesting does not occur, unless there are islets of 

 smaller stones amongst the larger. These islets are used 

 occasionally, even though little larger in area than the nest 

 itself. But the protection afforded to the nest by the sub- 

 stratum is inadequate, for the nest, together with the clutch, 

 break the monotony of the general surface, and are fairly easily 

 found. Though the young, in the act of crouching, may respond 

 to a larger boulder by moving up against it, they invariably rest 

 on shingle not larger and often smaller than themselves, and the 

 bulk of their activities, within the breeding territory, is confined 

 to areas of shingle whose components are of medium or small size. 



On the Biver Lyon a pair of Oystercatchers breed success- 

 fully on a small shingle island near Chesthill. The island is 

 wholly devoid of vegetation, and completely isolated by turbulent 

 rapids. The history of the settlement was not worked out. 

 But the difficulty of evoking the crouching reponse of the young 

 from the mainland, and the comparative indifference of the 

 adults to one's presence, render it unlikely that the young are 

 not born and bred on the island. Thus a local feeding-ground, 

 accessible to the young, is not a necessary condition of the 



