As I was outside attempting to capture more priceless shots of my feathered friends, I wondered if perhaps my bright clothing might be keeping the birds away. Would camouflage or certain colors be better? I had read at one point that birds abhor the color white and will keep their distance from bright white objects but, what is the truth of the matter?
As I researched, I found that birds can actually see colors that humans cannot. The human retina has 3 types of cone cells (I vaguely remember learning this in elementary school!). A human’s trichromatic vision is made of red, green, and blue cones. Birds, on the other hand, have 4 cones or tetrachromatic color vision and their vision includes ultraviolet light or UV light.
Birds also have a far great numbers of cones than their human counterparts. Humans have approximately 10,000 cones per square millimeter while songbirds, for instance, have about 120,000. This, in short, leads to increased visual acuity.
Adding UV to their field of view, birds can pick up on things that we humans cannot. For instance, when foraging for food a berry on a bush will be much brighter and vivid to a bird. Some berries, seeds, and fruits develop a waxy coating that is highly UV reflective. Certain butterflies, moths, and other insects also have coatings on their bodies that strongly reflect UV light. Lastly, birds of prey can follow trails of urine when hunting in fields which helps them track their next meal.
UV also helps some birds differentiate between their male and female counterparts. While some species look nearly identical to the human eye, to birds there is quite a difference! Take the blue tit for example, to the human eye they look identical however, when viewing their UV reflectivity it is clear to see that male blue tits have a highly reflective patch of feathers or “crown” on their heads while females do not.
And as for what I should wear while birding? Apparently some modern clothing dyes reflect UV and “brightening” agents in detergents can also be a problem. Birders can invest in a variety of sprayable fabric treatments in order to help camouflage themselves and tone down their clothing before a birding adventure. Perhaps I will do the same!
I hope you enjoyed learning more about these fascinating, winged creatures and their incredible traits!
Image is a female downy woodpecker; image credit Laura Y. Ceville @BirdHouseLove