Probably one of the most commonly acknowledged explanations for many female birds’ dull feathers is that they must blend in with their surroundings to protect their nests from predators. The bright colors of the females would make them and their nesting flock much more vulnerable to predators when they made their open nests.
For the majority of backyard bird species, males command attention with their vividly colored plumage. In the world of birds, it is typically the case that the male of the species is more vivid and visually arresting than the female. This leads to many female birds receiving less attention than males, particularly in identification and photography. However, female birds’ dull, frequently colorless feathers have a good explanation.
Darwin came to the conclusion that female preference for bright colors in males is largely responsible for color differences between sexes in birds (also known as sexual dichromatism). Since Darwin’s time, this general rule has been largely supported, but other influences have also been identified. For instance, females in species where they are exposed to predators during incubation typically have dull colors; however, in species that nest in tree hollows, where the females are less visible to predators, both sexes may have bright colors. Additionally, color can help people identify members of their own species. Additionally, colors in species that are dangerous to eat can alert potential predators.
It was only recently that scientists discovered that birds see a far wider range of colors than humans. Even their plumage contains colors that are invisible to the human eye. Birds are able to perceive the ultraviolet portion of the color spectrum because they have four color cones in their eyes, whereas humans only have three. Scientists have discovered that males in many species that appear to be monochromatic (those with similarly colored sexes, like European starlings) actually have bright ultraviolet colors that females use extensively when choosing a mate. These scientists have measured the extent of ultraviolet coloration using spectroradiometers.
In most bird species, but not all of them, males are more colorful or ornamented than females. A fundamental understanding of the evolutionary processes influencing the morphology and behavior of individuals and species is necessary to comprehend this phenomenon. Charles Darwin is largely responsible for developing the theory that explains this. According to his theory, sexual selection favors features that help members of a single sex (typically males) compete for mates, while natural selection favors traits that help individuals survive. Many traits specific to one sex in a species are the result of sexual selection. These characteristics can be broadly categorized into two groups: those that serve as weapons for males to battle for access to females (antlers on deer, for example) and those that serve as decorations to draw female attention (long tails on birds).
Male competitors for mates or resources like territory also use color as a tool. Vibrant hues can indicate that a space is already occupied, that the occupant is in good health, and that they are ready to battle. A great illustration is the red shoulder patch on red-winged blackbirds. The patch can be covered, and it is only visible to other members of the same speciesnever to predators. Compared to uncovered birds, males with experimentally covered patches had a higher tendency to lose their territories. Other species, like the scarlet-tufted malachite sunbird, have demonstrated similar outcomes, demonstrating that the brilliant badges’ primary purpose is to facilitate male-to-male competition for territories.
It was revealed for the first time in my research on eclectus parrots that both sexes can simultaneously evolve bright colors. Because of how dissimilar the bright green males and reddish-blue females of this species appear, it was first believed that they belonged to different species. Our eight-year research in northern Australia, which was published in the July 22, 2005, issue of Science, showed that the roles of the sexes are not the samefemales protect the young and incubate eggs. The females and males are different in that the females spend up to 11 months a year defending the nest hollow rather than going on food foraging with the males. To ensure that she and the chicks have all the food they need, each female depends on up to five males. Males have evolved their colors to blend in with the leafy foliage because they are more vulnerable to hawk predation while they are foraging. In the meantime, other parrots find their glossy green strikingly bright against the wood at the nest hollow. Additionally, the parrots’ ability to see is significantly superior to that of predatory hawks due to the ultraviolet pigments infused into the green. As a result, their color scheme strikes a deft balance between showiness and camouflage. However, there is less pressure from predators on the females, and their red and blue colors serve as a long-range signal to other females that they are present at the hollow.