Bec-en-croc de Temminck vs Bec-en-croc de Cayenne

The Hook-billed Kite and Grey-headed Kite can be distinguished primarily by their bill size and plumage patterns. The Hook-billed Kite exhibits a highly variable plumage with a distinctive bimodal bill size, while the Grey-headed Kite has a more consistent plumage and lacks the bill dimorphism.

Look for the bimodal bill size in the Hook-billed Kite, which is not present in the Grey-headed Kite. The Hook-billed Kite's plumage is more variable, while the Grey-headed Kite has a more uniform appearance.

The Hook-billed Kite has a highly variable plumage, generally banded rufous or gray below with a gray head and brown or gray back. In contrast, the Grey-headed Kite has a more consistent plumage pattern, typically with a gray head and white underparts.