21 



KEY C (Cont.) 



8' Proportions and colors in wings not as above; tarsi not so minute. 9 



9 Wing rather stubby - lengths of outer two primaries about equal and 

 not extending much beyond 8th or even 7th; folded wing curved in out- 

 line; body feathers close and compact; only 3 toes, all joined by webs 

 (Plate 36-1,2). See ALCIDS (Page 66) 



9' Not as in 9; wings more pointed - if the tips of primaries 10 and 9 are 

 about equal in extent, they extend decidedly beyond 8; folded wing 

 not decidedly curved; 4 toes. 10 



10 Tertials very long and pointed; feet webbed, OR only partly webbed, 



OR not webbed at all (compare Plates 35-37). 11 



10' Tertials not projecting beyond other secondaries to any great extent; 



3 toes, webbed their entire length. 12 



11 Wing narrow, ratio of width to total length is 0.27 - 0.31; 12 tail 

 feathers. See SHOREBIRDS (Page 42) 



IT Wing broader, ratio of width to length is 0.34 - 0.38; 12-24 tail 



feathers. See WATERFOWL (Page 33) 



12 Bird with distinctive musky odor (not that of rotting flesh!); 

 nostrils together in tube on top of bill (Plates 5 and 6); wings 

 long and narrow, ratio of width to total length 0.22 - 0.29 or 



less. See PETRELS (Page 27) 



12' No distinctive odor; nostrils not as in 12; wing broader. 13 



13 Feet with all 4 toes joined by webs (Plate 36-4); bill without nail 

 or hook at tip OR bill not duck-like; white all over except for 

 feather tips on back and several outer primaries being black. 



RED-BILLED TROPICBIRD 



13' Not as in 13. 14 



14 Upper surface of wing dark brown (sometimes with buffy edges to 

 coverts) except for white bases and shafts of outer primaries; toes 

 very long and toenails deeply hooked (Plate 35-1); legs blue and 



feet black. See JAEGERS (Page 50) 



14 Not as in 14. 15 



