The Surprising Fluorescent Wing Feathers of Long-Eared Owls
The long-eared owl, Asio otus, is a majestic raptor known for its perky horn-like ear tufts, and cryptic herringbone markings that help it blend into its arboreal habitat. However, scientists have recently discovered a hidden feature in these owls that adds a pop of color to their camouflage.
Ornithologist Emily Griffith and her team from Northern Michigan University and the Whitefish Bird Point Observatory in Michigan’s Upper Peninsula conducted a study on 99 long-eared owls during their migration in the Spring of 2020. They found that these owls possess fluorescent pink wing feathers that glow under certain light conditions, thanks to photosensitive pigments called porphyrins.
While the pink fluorescence is not visible to human eyes, owl eyes and other birds with ultraviolet vision can detect it. This unique feature may serve as a way for owls to signal to each other without alerting their prey, which mainly consists of rodents and small mammals.
The researchers also found that older owls had higher concentrations of fluorescent pigments in their feathers, with females having stronger pigments than males. This could potentially serve as a signaling mechanism for age, sex, and overall health in these birds.
While it’s still unclear why females exhibit brighter fluorescence in their wings, one hypothesis suggests that it could be related to heat regulation, similar to how fluorescent pigments in eggshells help regulate heat by reflecting infrared wavelengths. This could be particularly important for female owls during nesting periods when they are responsible for incubation.
Overall, the discovery of fluorescent wing feathers in long-eared owls adds a new dimension to our understanding of these fascinating birds. The research has been published in The Wilson Journal of Ornithology and sheds light on the hidden secrets of nature’s camouflage.
