50 



KEY TO SHOREBIRDS (Cont.) 



43 Legs and feet yellowish; throat white, with or without brownish 

 streaking; breast always with brownish streaking; bill width at 

 nail <1.4 mm; wing length 81-96 mm. LEAST SANDPIPER 



43' Legs and feet black; throat white and breast with gray or buffy- 

 gray wash OR throat rufous and breast with dusky streaking or 

 spotting; bill width at nail >1.4 mm; wing 93-108 mm. 



RUFOUS-NECKED SANDPIPER 



44 Bill length usually <20.0 mm; bill length <10 times bill width at 



nail. SEMIPALMATED SANDPIPER 



44' Bill usually >20.0 mm; length >10 times bill width at nail. 



WESTERN SANDPIPER 



KEY TO SKUAS AND JAEGERS 



1 Large and stout birds; wing length >380 mm; tarsus shorter than middle 

 toe with claw. SKUA, probably SOUTH POLAR SKUA 



1' Smaller and slightly built; wing <375 mm; tarsus longer than middle 



toe. 2 



2 Bill deeper than wide at base, 38-44 mm long; wing length 349-374 mm; 

 tarsus 48-55 mm. POMARINE JAEGER 



2' Bill wider than deep at base, 27-35 mm long; wing 295-341 mm; tarsus 



38-46 mm. 3 



3 Humerus (wing bone from shoulder to elbow) 94-105 mm long; tarsi 



and feet almost always black (occasionally bluish in juveniles); bill 

 saddle along culmen usually longer than chord of nail (see Fig. 5). 



PARASITIC JAEGER 



3' Humerus 83-88 mm; legs and basal half of toes and webs bluish, re- 

 mainder of feet black; bill saddle along culmen usually shorter 

 than chord of nail. LONG-TAILED JAEGER 



