Platyrhynchos: Anas

Distinguished by a glossy emerald-green head , white neck collar, and bright yellow bill.

Both sexes have a iridescent purplish-blue wing patch (speculum) bordered by white, visible during flight. Behavior and Ecology anas platyrhynchos

Mallards are significant hosts for avian influenza viruses (including H5N1) and are often studied in environmental toxicology. Distinguished by a glossy emerald-green head , white