46 WATER BIRDS 



is used of all terns. Tlie Least Tern is said to feed 

 upon insects, and has the peculiar darting, skimming 

 flight of swallows ; hence the appellation " sea swallow " 

 is particularly appropriate to it. Its call note is a high- 

 keyed squeal or squeak, and it utters this note almost 

 continuously while on the wing. 



Throughout the coast of Southern California these 

 Terns are found nesting on the narrow strip of beach 

 between the tide marsh and the sea. Along the old sea 

 drive, a few miles southward from Coronado Beach, it is 

 not uncommon to find their eggs laid on the bare sand, 

 at the edge of the salt marsh, well out of reach of the 

 tide ; but so perfectly do they harmonize with their 

 environment that the searcher may, and usually does, 

 pass them by, unless the distress of the parent bird or 

 the flushing of the mother from the nest betrays its 

 location. Even more difficult to find are the newly 

 hatched young, which are little balls of down scarcely 

 larger than a walnut, and seem to melt into the color 

 of the sand even after you have discovered them. 

 Crouched motionless among the pebbles, they do not 

 even wink until your hand almost closes over them, 

 when, presto 1 they scud off with most surprising speed. 



77. AMERICAN BLACK TERN. — Hydrochelidon nigra 

 surinamensis. 



Family : The Gulls and Terns. 



Length: 9.00-10.00. 



Adults in Summer : Head, neck, and under parts black | upper parts 

 uniform slate-gray ; bill and feet black. 



