40 BRITISH BIRDS. WITH THEIR NESTS AND EGGS 



The Rev. H. A. Macpherson, in his " Fauna of Lakeland," referring to the 

 colony of Common Terns that frequents Walney Island, observes that " at the north 

 end of the island the birds nestle on rough turf, but at the south end of Walney 

 almost all the nests are placed among the sand-hills. There are exceptions to 

 this practice. For example, in 1891 we found one nest of this species on the 

 open beach, a hollow in the pebbles, lined with rabbit bones, containing two eggs ; 

 a second nest was also placed on the beach above high-tide mark, lined with 

 small sticks, and containing a single egg. But we saw most nests in and among 

 the bents of the tall sand-hills, carefully watched by hundreds of parent birds, 

 which hover with shrill cries over the head of an intruder. Sometimes a bolder 

 bird than the rest returns to its egg within full view, but the majority circle 

 overhead, or dart angrily downwards until their solicitude has been lulled to rest. 



A much smaller number nest at the north end, lining some slight 



hollow in the turf with a few stems of grass, while even the newly hatched 

 nestlings, with instinctive dread of danger, crouch in the grass almost motionless 

 save for respiration." This Tern is very intolerant of cattle pastured in the 

 site chosen on the ground, and will attack them with violence ; and if much 

 intruded on will forsake the station. 



The Common Tern scoops out her nest-hollow, or lays her few straws in order on 

 the ground, about the middle of June, and thereon deposits two, or not more than 

 three, eggs, varying in size from ij( to if inches in length by about i inch in 

 diameter. These have a general ground colour varying from " stone-colour to 

 ochreous-buff or olive-buff, with spots or drops of black often merging into con- 

 fluent blotches, the underlying spots being faint purplish-grey and not very distinct. 

 Sometimes the variation in the depth of the colour of the egg is very marked, and 

 the ground colour is so deep a rufous-brown that the black markings are scarcely 

 perceptible. The markings are generally distributed over the surface of the egg, but 

 are sometimes congregated in confluent blotches round the larger end " (Sharpe). 



The nestlings emerge from the eggs after about three weeks incubation 

 during which one or other of the parents sits on the eggs all day, except in very 

 sunny weather, and never at night, or when it is wet, are they left uncovered 

 enveloped in a light brownish-yellow down, spotted or mottled with black ; the edge 

 of the wing and underparts (except the throat, which is brown) being white ; the 

 forehead brown and the feet yellow. They grow rapidly during the first few 

 hours, and one finds it hard to believe that, as Macpherson observes, " they were 

 ever packed away within a small and round egg-case." As the nestling grows 

 older the brown spots and moldings become more distinct. When fully-fledged 

 the forehead is brownish-white, the nape and rest of the head, including the ear- 



