30 



KEY TO PETRELS (Cont.) 



18 Under tail coverts white; feathers of forehead, face and sides of 

 neck white each with a central dark streak running along the shaft 

 giving a streaked appearance to these areas; coloration of bill 

 warm tan. STREAKED SHEARWATER 



18' Under tail coverts dark; feathers of forehead, face and sides of neck 

 usually dark but sometimes whitish and broadly tipped with dark 

 coloration imparting a speckled appearance to these areas; straw- 

 colored bill lighter than 18. PINK-FOOTED SHEARWATER 



19 Bill straw-colored; feet and legs light-colored (pinkish in fresh 



specimens); wing length 298-333 mm. " FLESH-FOOTED SHEARWATER 



19' Bill and feet dark (black to brownish or bluish); wing 263-320 mm. 



20 



20 Wing linings (under wing coverts) generally brown; small (wing 



263-290 mm, culmen 29-35 mm). SHORT-TAILED SHEARWATER 



20' Wing linings usually light gray, in some cases almost white; larger 



(wing 280-320 mm; culmen 38-48 mm). SOOTY SHEARWATER 



Figure 19. The length of upper tail coverts (rump feathers) 

 relative to the length of the tail: tail coverts 

 (a) about 1/2 the tail length and (b) about 2/3 

 the tail length. 



