276 THE BIRDS OF THE BRITISH ISLES. 



but the return, though regular, is not annually on a given date, 

 as lighthouse-keepers, and even Prof. Newton, would have us 

 believe. A few arrive in March, but the majority come later, 

 and departure, which begins in August, often drags on until the 

 middle of September. Holes or burrows, not exposed ledges, 

 are the nesting sites, consequently the biggest colonies are 

 on turf-covered islands, or the grassy slopes of cliffs. At the 

 colony the birds swarm, many loitering aimlessly, others ex- 

 cavating, or attending to various domestic duties. The Puffin 

 stands on the toes — popularly called the foot — and does not 

 rest upright on the whole length of the tarsus like a Guillemot, 

 in the attitude often pictured and even recently described ; 

 I have never seen the bird sink on to the tarsus except as a 

 preliminary to its position of ease, when the breast rests upon 

 the ground. When walking it has a nautical roll, due to its 

 short legs and the ppsition of the feet, but it walks without 

 labour and can run quickly. A bird may often be seen chasing 

 another with head held low, and if the pursued is overtaken 

 the big bills will be interlocked, and with much growling 

 each appears to be striving to wring its rival's neck. On 

 the sea near the colony the birds swim in hundreds ; the 

 brightly coloured bill alone serves to distinguish them from 

 their companions, Guillemots and Razorbills. 



The Puffin dives without effort, and under water swims with 

 wings alone. The flight differs from that of other auks. When 

 turned out of its burrows the bird runs down the slope towards 

 the sea, often tumbling in its haste, and with open and quivering 

 wings slowly rises like a starting aeroplane. Mr. O. V. Aplin 

 points out that when the bird rises clear the feet are gathered 

 beneath it with *' unctuous palms " meeting, but as it descends 

 towards the water are extended on either side of the tail. In the 

 oblique descent they function as rudders and balancers, but are 

 again drawn together when it skims out, perhaps for half a mile, 

 low over the water. The pose of the body during the aerial dive 



