With two of five of the atlas project's breeding seasons now under our belts, we have at least one confirmation for almost all of San Diego County's regular nesting species. Perhaps the commonest species among the ten or so still unconfirmed during the last two years is the Redhead. These two ducks occur in San Diego County primarily as winter visitors, and though relatively easy to distinguish have been confused, making them a suitable topic as we embark on our second winter season. The Redhead and the Canvasback, both diving ducks of the genus Aythya , share many characteristics.
Males have reddish heads, black breasts, and largely grayish bodies.
The Canvasback's head has a peaked crown and a sloping forehead that grades smoothly into the long bill with a much deeper base. The Canvasback's triangular profile thus resembles more that of a scoter, eider, or Trumpeter Swan. By contrast, the Canvasback's back often looks an almost gleaming white. The birds' plumage is sometimes stained brown, obscuring the natural color. Early in the winter, shortly after the birds arrive, males may retain some juvenile or eclipse plumage.