34 



KEY TO WATERFOWL (Cont.) 



2' Wings largely white except for black primaries; primaries 10-8 have 



one or both webs cut out; medium large bird, wing 318-402 mm. 4 



3 Tail of 20 feathers; usually, but not always, a yellow spot in front 

 of eye; distance from tip of bill to anterior edge of nostril <48 mm; 

 wing length 500-575 mm. WHISTLING SWAN, adult (all white) or 



immature (gray wash to some feathers) 



3' Tail of 24 feathers; never a yellow spot in front of eye; distance 

 from tip of bill to anterior edge of nostril > 50 mm; wing 544-680 mm. 



TRUMPETER SWAN, adult (all white) or 

 immature (gray wash to some feathers) 



4 Bill length 50-63 mm; sides of bill open in a "grin" as in Plate 12a-2, 

 where "grin" is >l/3 the bill depth; wing length 380-470 mm. 



SNOW GOOSE 



4' Bill 34-46 mm; not as open on sides, "grin" <l/3 the bill depth; 



wing 360-400 mm. ROSS' GOOSE 



5 Tarsus with scutellate scales along front edge (Fig. 13); no primaries 

 cut out OR just primary 10 cut out on inner web OR primary 10 cut out 

 on inner web and 9 cut on outer web OR primaries 9 and 10 cut out on 

 outer webs. (DUCKS) 10 



5' Tarsus with reticulate scales along front edge; three outer prim- 

 aries cut out: 10 on inner web, 9 on both webs and 8 (sometimes 

 only slightly) on outer web. (GEESE) 6 



6 Head and neck black with white cheeks or a white collar (Fig. 12); 



feet and legs black. 7 



6' Head and neck not black (except perhaps throat); feet not black. 8 



7 Black ends at base of neck; white cheeks; upper and under tail 



coverts not nearly as long as tail. CANADA GOOSE 



7' Black of neck extends to back and breast; white collar (Fig. 12d); 

 dark cheeks; upper and lower tail coverts usually as long as or 

 longer than tail. BRANT 



