are they under threat?
No, they are in fact rated as a species of least concern.
Mallard
Since 1998, the mallard has been rated as a species of least concern on the IUCN Red List of Endangered Species
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.
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Mallard [SEP] Status and conservation
Since 1998, the mallard has been rated as a species of least concern on the IUCN Red List of Endangered Species. This is because it has a large range–more than 20,000,000 km (7,700,000 mi)–and because its population is increasing, rather than declining by 30% over ten years or three generations and thus is not warranted a vulnerable rating. Also, the population size of the mallard is very large. Unlike many waterfowl, mallards have benefited from human alterations to the worldso much so that they are now considered an invasive species in some regions. They are a common sight in urban parks, lakes, ponds, and other human-made water features in the regions they inhabit, and are often tolerated or encouraged in human habitat due to their placid nature towards humans and their beautiful and iridescent colours.