can you name any birds that have it?
Many ducks, species such as red junglefowl , painted bunting etc.
Plumage
Many ducks and some other species such as the red junglefowl have males wearing a bright nuptial plumage while breeding and a drab "eclipse plumage" for some months afterward. The painted bunting's juveniles have two inserted moults in their first autumn, each yielding plumage like an adult female.
when does a male mallards head turn green During the final period of maturity leading up to adulthood (6–10 months of age). what kind creatures are they? A dabbling duck . what are their food habits? Their diet consists mostly of gastropods, invertebrates (including beetles, flies, lepidopterans, dragonflies, and caddisflies), crustaceans, worms, many varieties of seeds and plant matter, and roots and tubers. can they be raised as pets? Yes, even though this trend is not very popular. is the meat of the bird consumed? Yes, both eggs and meat are consumed. are they under threat? No, they are in fact rated as a species of least concern. where are they widely found? Throughout the temperate and subtropical Americas, Eurosiberia, and North Africa  along with New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. how do they look like? The male birds have a glossy green head and are grey on their wings and belly, while the females  have mainly brown-speckled plumage. how does the last mentioned word came into existence? UNANSWERABLE
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Plumage [SEP] Introduction
The painted bunting's juveniles have two inserted moults in their first autumn, each yielding plumage like an adult female. The first starts a few days after fledging replacing the "juvenile plumage" with an "auxiliary formative plumage"; the second a month or so later giving the "formative plumage". Abnormal plumages include a variety of conditions. Albinism, total loss of colour, is rare, but partial loss of colours is more common. Some species are colour polymorphic, having two or more colour variants. A few species have special types of polymorphism, as in the male ruff which has an assortment of different colours around the head and neck in the breeding season only.