Science
Muser Press
The five bird species (from left to right: great-horned owl, common raven, Stellar's jay, bobwhite, and song sparrow) showed remarkable similarity in mid-infrared radiation – except for bobwhites. Credit: Allison Shultz
Researchers measured mid-infrared radiation from bird feathers for the first time, showing birds can emit heat into space. Most species showed similar patterns, with notable variation in bobwhites.
A nitrogen-purged Fourier transform infrared (FTIR) spectrometer (Nicolet TM iS50, Thermo Scientific Fischer, USA) equipped with an integrating sphere (Upward IntegratIRTM, PIKE Technologies, USA) measuring NIR and MIR in a bobwhite specimen. Credit: Thomas Lee
The team examined five North American bird species using museum specimens, measuring reflectance across ultraviolet, visible, near-infrared, and mid-infrared wavelengths.
Among the five species examined, Northern bobwhites showed the greatest variation in mid-infrared reflectance. Credit: iNaturalist observation by Adam Jackson | Public domain
Mid-infrared emission was largely consistent across species, but Northern bobwhites showed greater variation, likely linked to their exposure to open environments where heat radiates into the sky.
Northern bobwhites showed notable variation in mid-infrared reflectance among the species studied.
The findings expand understanding of animal coloration and thermoregulation, with potential applications in conservation and the design of materials that passively manage heat.