This light absorption is in the visible spectrum. The absorbed light is emitted as infra-red.
"Making synthetic ultrablack materials tends to be expensive and requires the use of toxic substances, such as carbon nanotubes. But the black feathers of the magnificent riflebird (Ptiloris magnificus), native to the rainforests of New Guinea and northern Australia, naturally absorb an astounding 99.95 percent of light."
https://nautil.us/how-this-colorful-bird-inspired-the-darkest-fabric-1252079/





