Identification - bills
Lesser and Greater have ‘grinning patches’ - tomia of both
mandibles are black. Ross’ does not have an obvious grinning patch.
Head feathering on Greater and Lesser extends onto bill in a
U-shape. Ross’ feathering meets the bill in a vertical
line.
Bill of adult Greater & Lesser uniform pink. Bill of Ross’ pink
with olive-gray to purple caruncles on basal end of upper mandible.