SAND-MARTIN. 25/ 



all directions flocks of a score or two to hundreds of birds 

 arrive and begin aerial evolutions, wheeling in ordered com- 

 panies, twittering continually. The host breaks up, the birds 

 cross and recross one another's paths, and then reform into 

 long lines which undulate across the sky like blown smoke. 

 Often the whole body soars and after a few turns and. circles 

 begins a curious spiral descent, the leading party wheeling 

 repeatedly, guiding the twists of a descending screw. When 

 still some height above the reeds the birds half close their 

 wings and shoot down diagonally, jerking from side to side, till 

 with opened wings they check descent. Then in the waning 

 light they skim to and fro with rapid flight, just above the 

 reeds, into which they suddenly and imperceptibly vanish. 

 Party follows party, but the later comers go through shorter 

 performances and drop at once to the roost. In the south birds 

 are noticed in October, but north of the midlands most leave 

 early in September. I have a report of a number seen late in 

 December in Devonshire, but this is very unusual. 



The Sand-Martin is hair-brown above, white below with a 

 narrow brown band on the breast ; the bill is black, the legs 

 and irides brown. The young have rufous tips to the coverts 

 and margins to the secondaries. Length, 4*8 ins. Wing, 4 ins. 

 Tarsus, '45 in. 



Order PICIFORMES. 



Sub-order PI CI. 



The order Piciformes includes the Woodpeckers and Wr}'- 

 neck, birds with zygodactyle or ''yoked" feet, two toes pointing 

 forward, two backward. These feet, though adapted for clinging 

 to a vertical surface, can be used for grasping or perching. The 

 long tongue, which can be darted forward to capture insects, is 

 a character of the group, though it is not confined to this order. 



Series I. S 



