FAM. LXIV. GBEBES 



345 



They have the power, when alarmed, of sinking quietly back- 

 wards into the water and then swimming almost any distance 

 with only the tip of the bill above the surface. Like all of 

 the divers, their food consists mainly of fish, which they are 

 able to catch under water by their rapid swimming, using their 

 feet alone for propulsion. In this they differ from the auks, 

 which use both legs and wings. 



Key to the Species 



* Bill stout and somewhat hooked, Its length not quite twice its greatest 



depth at base ^ 6. Pled-billed Grebe. 



* Bill straight and more slender, its length more 



than twice its depth at base. 2 (A.) 



A. Culmen more than 2^ long 



1. Western Grebe. 



A. Culmen, 1 J-2| long ; wing over 6 long 2. Holboell's Grebe. 



A. Culmen, ^1^ long ; wing under 6 long. (B.) 



B. Wing under 4J long 5. St. Domingo Grebe. 



B. Wing, 4^6 long. (C.) 



C. Bill flattened sidewise and thus higher than wide at base 



3. Horned Grebe. 



C. Bill wider than high at base 

 ... 4. American Eared Grebe. 



1. Western Grebe (1. u^ch- 

 muphorus occidentdlis). — A very 

 large, long, slender-billed, mot> 

 tied, brownish - backed grebe, 

 with all the under parts satiny 

 white. The primaries are choc- 

 olate-brown with white bases, 

 and the secondaries are mostly 

 white. It has a short crest and 

 puffy cheeks. This is a com- 

 mon grebe of the extreme west. 

 The grebes rarely fly to escape 

 their enemies, but depend upon 

 their diving and swimming 

 powers. 



Western Grete 



