53 



KEY TO GULLS (cont.) 



Figure 23. Color patterning in the extended wings of (a) 



immature Black-legged Kittiwake and ("b) immature 

 Bonaparte's Gull, and (c) immature Sabine's Gull. 



c, 



14 Wing bar at base of secondaries black; tail distinctly wedge- 

 shaped (central tail feathers longer than outer tail feathers). 



ROSS 1 GULL, first year 



14' Wing bar at base of secondaries brown; tail not as above. 



BONAPARTE'S GULL, first year 



15 Tail white with black band; top of head, neck and back uniformly 



brown; wings with brownish cast. LAUGHING GULL, first year 



15' Tail white or nearly so; top of head, neck and back not uniformly 



brown. '" 



16 Head white with dusky spotting on nape usually extending down neck; 



wings with brownish cast. LAUGHING GULL, second year 



16' Head hooded with black (summer) OR white with dusky spotting on 

 upper nape (winter); wings without brownish cast. 



LAUGHING GULL, adult 



