Canvasbacks are often confused with redhead ducks, even by an expert bird guide. However, they are quite easy to distinguish if the bird guide knows to look for their dissimilar physical characteristics. Both the birds are found in the same geographical range, but the canvasbacks are quite a lot larger than redheads. Canvasbacks have a sloping profile and a sharp bills, while redheads look more like a duck with their blue or grey-coloured bills and round heads. The males of the canvasback species have a bright-coloured chest and belly, while redhead males have a gray-coloured chest and belly.