When it comes to the most beautiful animals on Earth, there are many out there who would say birds are one of the best examples. There may be a few reasons for this but one of them is undoubtedly their striking plumage.
Even with earthy colors, the patterns on some birds can be beautiful. And on others, deep blacks and pure whites can be stunning to see. Of course, there are many others which have a beautiful range of stunning colors. But why is this? Let’s find out.
The Science Behind Bright Plumage
The colors of birds, such as the stunning scarlet macaw, are mostly due to different pigments. Melanins are what determines skin color in humans, and unsurprisingly these chemical compounds can produce blacks, greys, and browns.
Carotenoid pigments can create reds, oranges, and yellows in birds but have to be supplemented from their diet. Porphyrin pigments can generate greens and pinks but are less common and also will degrade over time due to exposure to UV rays.
There can also be structural coloration to birds. These are microscopic structures of a feather that can scatter light, creating iridescent colors. For birds such as hummingbirds and kingfishers, this can change the color of feathers depending on the angle of light, giving them a shimmering appearance.
The Role of Sexual Selection
There’s the science about the colors of birds, but why do they have such a variety? In many species it comes down to trying to attract a mate. For species such as the peacock, the male will have much grander and colorful plumage than the female, in order to attract her as a mate.
We mentioned above how diet can impact plumage. The bright plumage from a male can be an indicator of their health and fitness, showing they are capable of having access to a healthy diet and are free from disease or parasites.
Males will use these bright colors to compete with their rivals. The more striking their feathers, the more likely they are to secure a mating opportunity. This, of course, then links in with selective breeding as only the birds with the best colors are selected as a mate. And these genes are passed down.
Camouflage and Predation
In birds, it is common for there to be sexual dimorphism. This is when different sexes of the same species can look strikingly different. Ducks can be a common example of this, with a great example being the male mallard.
A male mallard will have the same duller plumage as a female mallard until they reach sexual maturity. During breeding season, sexually mature mallards will then develop bright colors to attract females. Fascinatingly, the male mallards will then molt and lose these colors and once again resemble a female mallard until the next breeding season.
This is for survival reasons. The duller colors will help birds blend in with their surroundings, especially for females during nesting periods. For males that lose their color, it makes them less of a target for predators when they don’t need to be sexually active.
In hotter climates, bright colors can be better for camouflage where their vivid colors are more likely to blend into the foliage and treetops, making them harder to spot. As with a lot of things in the animal kingdom, the answer mainly boils down to reproduction and survival.
Role in Communication
Bright colors can also be a means of communication. Bright plumage can be an indicator of territorial dominance. Some species will use their feathers as a way to show their power and prevent the need for conflict.
They can also be an indicator of social status. Color intensity can change based on how dominant a male is. For example, with house sparrows, males with larger and darker throat patches are seen as higher in their social hierarchy.
Another reason is species recognition. Different colors and patterns can allow birds to more quickly identify members of their own species, especially in areas where multiple species co-exist.
Ecological Factors Affecting Bird Colors
The environment can play a large role in the evolution of bright colors. Carotenoid-rich foods such as berries and insects are more likely to give birds red, orange or yellow feathers. Flamingoes famously get their color like this and will get a darker shade of pink the more carotenoid-heavy their diet is.
Tropical regions often have abundant resources and allow brightly colored birds to keep their color all year around. In more temperate climates, birds may find access to food more difficult and have evolved to better camouflage into their less colorful environment.
For birds in tropical regions, brighter colors can be helpful when it comes to avoiding prey. Not only do they blend in better with the brighter surroundings, but their plumage can distract and confuse predators, making them harder to catch.
Evolutionary Reasons for Bird Coloration
Evolution has played a key role in bird color. We’ve already mentioned the obvious point about how colorful males are more likely to breed, but it can go deeper than that. For example, in the past, random genetic mutations would have caused new coloration patterns. If these traits were an advantage for any reason, they are more likely to be passed down.
Birds also learn how to adapt. If they have colonized a new environment, they can evolve distinct plumage to adapt to their new surroundings. Many of these changes could have happened millions of years ago.
There is also the matter of speciation, when one species branches off to form another. This can happen for many reasons, but one of them can be when birds with unique plumage or a certain pattern will only mate with others that share that coloration.
Human Influence on Bird Coloration
Unsurprisingly, there has also been a human influence on bird coloration. It has been found that some birds have adapted to urban settings by actually becoming more colorful. This is possibly due to both a change in their diet but also fewer predators.
There is also the influence of domestication. Many birds have been selectively bred for their bright colors, with parrots perhaps being the best example. Over time, these birds have become even more colorful with only the most beautiful being selected for breeding.
As you can see, the answer to why are some birds so brightly colored can be multi-faceted. For many it’s a way to attract a mate but it can also be for camouflage, communication, diet, and even selective breeding.
