THE SAND MARTIN. 2So 



period of their year, that of nidification ; but from the 

 description by Professor Eennie (" Bird Architecture") and 

 that by Mr. E. D. Duncan, quoted by Macgillivray,* the 

 sight must be most interesting. The task of the older birds 

 must be a hght one : not so, however, that of the younger 

 members of the flock. The former have neither walls nor 

 roofs to repair ; the holes which served them as nests the 

 previous year, afford the same accommodation as before. 

 All that is needed is, that the remains of the old nest 

 should either be removed or receive the addition of a few 

 straws and feathers to protect the eggs and young from 

 direct contact with the cold sand ; their labours then are 

 over. But the new colonists have a toilsome work to 

 perform before they can enjoy the gratification of bringing 

 up a family. The settlement is fixed probably in the 

 perpendicular face of a bank of sand, gravel, or clay, at an 

 elevation from the ground which varies from a few to a 

 great many feet. Their claws are sharp and well adapted 

 for clinging, the beak short, rigid, and pointed, no less 

 well suited for excavating. Grasping the perpendicular 

 surface of the bank with their claws, and steadying them- 

 selves by means of their tails, they commence operations 

 by pricking a small hole with their bills. This hole they 

 gradually enlarge by moving round and round, and edging 

 off the sand with the side of their bills, which they keep 

 shut. Their progress is slow at first, but after they have 

 made room to stand on the excavation, they proceed 

 rapidly, still working with their bills, and carefully pushing 

 out the loosened sano with their feet. At one time the 

 male, at another the female, is the excavator. When their 

 burrowing is impeded by the resistance of a stone, they 

 either dig round it and loosen it, or, if it prove so large as 

 to defy removal, they desist and begin another cell. The 

 form of the hole varies both in size and shape, but it rarely 

 exceeds three or four iaches iu diameter, and more or less 



* British Birds, vol. ill p. 600, 



