A team of researchers from various U.S. universities have discovered why birds-of-paradise evolved such dark feathers, a new study published today in Nature Communications reports.
Birds-of-paradise are known for their unique mating dance, where they hop around and flash their feathers in order to attract a mate. Their coloration is a big part of that dance. Their feathers have spots of color, but they are mostly black. So black, that scientists in the study did not believe the bird’s coloration came from pigment alone. Rather, they think the species evolved “super black” feathers that make bright hues stand out even more.
“In this case it’s sexual selection,” said lead author Dakota McCoy, a researcher from Harvard University, according to Gizmodo. “Males are trying to attract females—in these birds, females pick who they want to mate with. A single feather askew is enough for them not to mate. It’s like an arms race. Males have to find ways to make their colors look even better to the female.”
The team reached this conclusion by using scanning electron microscopes and CT scanners to observe the differences between regular-black and super-black feathers. They found that, while regular black feathers simply have single barbs attached to a main stem, super-black feathers are covered in tiny spines.
Those small structures are important because they have the same “structural absorption” as manmade super-black materials, which means the feathers absorb 99.95 percent of light shined at them.
“This is definitely not about camouflage,” said Matthew Shawkey, an evolutionary biologist at Ghent University in Belgium who was not involved in the study, according to Scientific American. “This super-black plumage is enhancing the contrast with those bright-colored feathers nearby.”
This research is important because it provides new information on super-black structures. The team believes the research could lead to cheaper materials and one day create more cost effective textiles and solar panels.