Feathers Unfurled: Exploring Weird Plumages in Wild Waterfowl

By Kai Victor

Feathers may be the most important avian feature. They allow flight, retain body heat, shed water, provide camouflage from predators, and attract mates. They also help us tell different species of birds apart. And while most birds from the same species look alike, sometimes an individual with a uniquely colored appearance shows up. Thanks to our active waterfowl hunting and wildlife viewing communities, these birds with unique plumage colors, or "mutations," are regularly spotted and documented.

The following is an overview of some atypical plumages in waterfowl you may see or have already been fortunate to see—down the barrel of your shotgun or through a pair of binoculars.

Color Mutations

It's important to note that there are countless color varieties in domestic ducks that descended from mallard ancestors. Domestic ducks can breed with wild birds, sometimes producing wild ducks with white patches or off-colored feathers. Some indications of domestic parentage include a larger body size, shorter bill, and plumper build.

Color mutations in wild waterfowl generally fall into two categories: those that are associated with white plumage and those that are not. The interplay between various pigments in the feathers, skin, and eyes often causes these color mutations. One of the most important pigments contributing to these mutations is melanin. This dark pigment can help protect the body from UV radiation. Melanin production is what causes people to tan in the sun.

White Plumage

Three conditions commonly associated with white plumage are albinism, leucism, and piebaldism. All three have been confirmed in a wide variety of duck species.

Albinism is probably the most well-known mutation, thanks to the red-eyed and white-furred mice, rats, and rabbits we associate with pet stores and laboratories. Albinism can affect various animals and has been observed in mollusks, amphibians, reptiles, birds, and mammals. Albino birds lack melanin in their feathers, eyes, skin, or bills. This usually leads to entirely white feathers, red eyes, and pale skin. In addition to being light-sensitive, albino birds have poor vision and low survival in the wild.

Leucism is similar to albinism in that birds with this condition tend to have uniformly pale plumage. However, unlike albinism, the plumage colors of leucistic birds can vary. While some individuals may be almost pure white, others may display a diluted version of their normal color and pattern. This is because leucism describes a particular individual's general appearance, or "phenotype."

Unlike albinism, which is caused specifically by the loss of melanin, leucism can be caused by various underlying conditions that affect the appearance of a bird in different ways.Leucistic birds have normally colored feet and bills and may have blue, black, or normally colored eyes. In general, leucistic birds are only considered truly leucistic if their plumage is uniformly pale. In many cases, individuals may display only partially leucistic plumage in the form of patches of white or single white feathers. These individuals are known as piebalds.

Piebaldism is one of the most common color mutations. The reasons for this vary, but with normal eyesight and less white in their physical features, individuals with this condition are better able to avoid predation than leucistic or albino individuals. Evidence of piebaldism in wild mallards can be very similar to evidence of domestic ancestry, so be careful when attempting to identify amallard with white feathers.

Non-white Plumage

A variety of other non-white plumage patterns exist in birds. Melanism, which is caused by an excess of melanin in the body, is the most common. Melanism is relatively common in various cat species, such as the "black panther" form of the leopard. In general, melanistic birds possess typical plumage patterns and colors, but feathers that are normally pale are dark or completely black. This condition appears to have been confirmed in mallards and ruddy ducks.

Xanthochromism is a condition in which animals display an excessive amount of yellow coloration, and it is usually caused by a lack of red pigment. Xanthochromism can be associated with a bill and skin that is either normally colored or yellowish. While this condition has not yet been documented in waterfowl, it has been detected in a variety of wild bird species, and it’s a common mutation in captive parrots.

Axanthism is similar to xanthochromism, except it is caused by a lack of yellow pigment. Affected animals may appear gray, black, or even blue. No waterfowl have been observed with this condition either, but it occurs in various captive parrot species.

Mutations in captive waterfowl populations are another potential source of any weird, wild birds you may encounter. Generations of selective breeding in captive birds have led to such exotic "morphs" as platinum wood ducks, silver redheads, and blue pintails. . While these birds would be rare escapees, it's always important to remember them when you’re considering where a unique-looking duck might have come from.

Lastly, there will always be a few odd ducks out there. Maybe they don't have any of the above conditions, or maybe they have a combination of them. Maybe there's some domestic ancestry in there. Maybe you’ll get lucky and see a gadwall with a neck ring or a mallard with a gray breast.

Sexually Reversed Plumage

The last topic we'll cover is sexually reversed plumage. While the males and females of a few North American duck species, such as whistling-ducks and American black ducks, have the same plumage type, most species have sexually dimorphic plumage, which means that males and females look different .

With most ducks, it's easy to tell adult males and females apart for most of the year. However, in many species, males will molt into an eclipse plumage after the breeding season. At this time, they look very similar to female ducks. Unfortunately, for all you plumage enthusiasts, it gets even more complicated. Female ducks usually only have one functional ovary. If this ovary gets damaged, their production of estrogen hormones stops. Because male plumage is the default condition in ducks, females require normal levels of estrogen to prevent them from developing male-like characteristics. Remove the source of these hormones, and you will get a female duck with male plumage! Crazy, huh? This condition is believed to be most commonly caused either by damage to the one functional ovary or by a natural decline in the production of oestrogen as females age. If you happen upon a duck showing both male and female characteristics, this might be the reason.

Get Out There

So how can someone increase their chances of coming across one of these special ducks in the wild? A few situations may promote the occurrence of plumage mutations and the long-term survival of ducks with these conditions. Many plumage mutations are genetically recessive, so inbred populations are more likely to display them. Additionally, the survival of birds with these mutations is likely to be highest in areas with reduced predation and competition. But in the end, these ducks are special for a reason, and there aren't many out there. If you're fortunate to encounter one, you're a lucky duck!