Birds of paradise have always attracted the attention of scientists and nature lovers with their stunning plumage and complex mating rituals. Their bright colors are the result of complex processes of light reflection and absorption, but now it has been discovered that their appearance is even more amazing.
The researchers found that most species of birds of paradise have biofluorescence - the ability to absorb ultraviolet light and emit it at longer wavelengths, making their feathers literally glow.
A study conducted by a team at the American Museum of Natural History in New York led by Dr. Renee Martin found that 37 of the 45 species studied exhibit some form of biofluorescence. The scientists studied museum specimens of birds of paradise by placing them in a darkened room and illuminating them with blue and ultraviolet light.
Special equipment recorded the wavelengths and intensity of the light emitted, allowing us to determine which parts of the birds' body or feathers had this unique ability.
The results surprised the researchers: it turned out that most birds of paradise have luminous areas concentrated on the head, neck, breast, tail and near the beak. Moreover, in some species, the inside of the beak and throat area also show glow. According to Dr. Martin, this discovery changes the way we think about the appearance of these exotic creatures.
"At a minimum, the biofluorescent areas appear brighter than under normal light. For example, yellow feathers become more saturated, with a greenish-golden hue, and white areas glow with a slight green glow," she explains." she explains.
Biofluorescence has been found in both males and females of most species, but its function may differ. In males, luminescence is most pronounced in areas associated with mating behavior, such as the head, neck, and tail. Many species of birds of paradise are known for their elaborate courtship rituals in which they spread their feathers and display brightly colored areas of plumage.
Scientists hypothesize that biofluorescence enhances visual cues during the mating dance, helping to attract females.
For example, Lophorina males open their beaks wide in front of the female during courtship, and the glow inside the beak can make this gesture even more spectacular.
In females, the luminous areas are located slightly differently. They are more often found on the abdomen, breast and in the form of a stripe around the eyes. This led the researchers to think that biofluorescence in females may play a protective role, helping in camouflage. This arrangement of luminescent areas may soften body contours in natural light, making the bird less visible to predators.
Although the discovery of biofluorescence among birds of paradise was a sensation, the researchers found that not all species retained this feature. Species belonging to the genera Lycocorax, Manucodia and Phonygammus do not possess biofluorescence. Scientists believe that the ability to glow was originally present in the common ancestor of all birds of paradise, but was subsequently lost in some species during evolution.
"This finding gives us further evidence that biofluorescence was an important part of the evolutionary strategy of birds of paradise, but under certain conditions it was no longer necessary," notes Martin.
Why these species lost their biofluorescence remains a mystery. Perhaps their reproductive or defense strategies have evolved in a different direction, making luminescence unnecessary.
Biofluorescence is common in many animals, including
corals, insects, amphibians and some mammals. However, it is extremely rare among birds, and its discovery in birds of paradise may mean that scientists have underestimated its importance in ornithology.
Researchers suggest that the luminous areas help birds of paradise to better recognize each other. It is known that the vision of birds is different from that of humans: many species are able to perceive the ultraviolet spectrum, which is inaccessible to human eyes. Thus, birds can see richer and brighter colors.
Birds of paradise are some of the most studied and fascinating creatures on Earth. However, even they continue to surprise researchers. "We thought we knew everything about birds of paradise, but it turns out that even their appearance hides undiscovered secrets," says Martin.
This research opens new avenues for studying the behavior,
evolution and biology of these amazing
birds. In the future, the scientists plan to continue their work to find out exactly how birds of paradise use biofluorescence in nature, and what mechanisms are behind the phenomenon. Perhaps ideas about color in the feathered world will change dramatically.