Fig. 1From: Sex determination based on morphometric measurements in yellow-legged gulls (Larus michahellis) around IstanbulA The relationship between head length (HL) and bill length-1 (BL1) in function D1. B The relationship between head length (HL) and bill length-3 (BL3) in function D2. C. The relationship between head length (HL) and bill depth-1 (BD1) in function D3. D The relationship between head length (HL) and bill depth-2 (BD2) in function D4 ( : female; : male)Back to article page