SAND-MARTIN 311 



till May, the earliest birds being in advance of the proverbial first 

 swallow. As, unlike its congeners, it avoids human habitations, its 

 movements after its arrival we not well known. It apparently deei 

 not resort at once to its nesting-place, but goes to its favourite feed- 

 ing haunts, which are usually, if not always, near and over water. 

 There it may be seen hawking for flies much like swallows and house- 

 martins, and often in company with them. Like them, again, it will 

 at times pick its food off the surface of the water. But feeding is not 

 its only occupation at this time. Its attention is largely engaged by 

 love affairs, as is evident from the fighting and quarrelling that takes 

 place in mid-air, and which sometimes ends in the combatants 

 i;il I ing together to the ground The fact that there is fighting does 

 not, of course, invalidate the view that the birds pair for life. The 

 fighting may be due to rivalry between miniated males, principally 

 the young of the previous year ; and not only so, but also between the 

 unmated and the mated, for, as we have seen in the case of the 

 wallows (p. 299), the latter have not infrequently to fight for their 

 spouses even after nesting operations have commenced. Whether 

 the successful males win by force of valour only, or whether they add 

 some form of love-display, still remains to be ascertained. 



In their nesting habits sand-martins differ considerably from the 

 swallow and house-martin. The latter build mud-nests in or about 

 houses, on the face of cliffs and in caverns, the former usually tunnel 

 a hole into bank, pit, or cutting, and make at the end of it a rounded 

 chamber, in which they place a rough thick bed of straw, feathers, or 

 other material This lining is the only point in which their nests 

 resemble that of their congeners. 



The tunnel, which may be straight or sinuous, inclined upward or 

 nearly horizontal, is usually two or three feet long, and it may be two 

 to three inches in width, and double this in the terminal chamber. 

 Generally most of the holes are to be seen extending in an irregular 

 line along the upper part of the pit where the soil is soft The 

 number seen does not represent the number of nesting pairs. Some 



