During these times of uncertainty I have been taking comfort in the things that remain constant in the world around us. The birds are still singing, the rain is still falling and the bees are still pollinating. Life is going on all around us, as it has long before the current state of things, and hopefully as it will long after!
As I take in the world around me, I have noticed myself focusing more and more on colors; particularly the colors on birds. The coloration we notice on birds is often not the whole story. Many birds have coloration only visible to creatures that can see into the ultra violet portion of the light spectrum. It may seem like something from science fiction to say that there are colors in this world that we have never seen, but it’s true! Our human eyes only have three types of cones, or color sensing cells, that allow for us to see light in the visible light spectrum. These cones most effectively pick up red, blue and green wavelengths. For a touch of perspective, dogs have two types of cones, birds have four, and mantis shrimp have sixteen! The same environment would look vastly different to each species.
The extra cone type present in birds’ eyes picks up violet or ultraviolet light, depending on the species of bird. This allows them to see things our eyes and brains are unable to even contemplate.
That in itself is quite incredible to consider, but let’s talk about how that applies to birds in our life. Regardless of whether you are an avid birder, or a casual backyard bird fan, you are likely able to tell a male and female mallard duck apart from each other. They are sexually dimorphic; looking different from each other in ways that we can see. In the case of mallards the males have a stunning emerald head. But what about a chestnut backed chickadee? Or a song sparrow? A barred owl? There are many bird species that are considered sexually monochromatic; the males and females look the same, even to expert birders.
To birds though, there is quite a high likelihood that there are obvious visible differences in patterns and colors between the males and females of a species. One study took 139 “sexually monochromatic” songbirds of North America and found that a whopping 90% of them had color and pattern differences that would be visible to birds (Eaton, 2005), but that we cannot see. The birds we’ve always considered drab should now be contemplated with an appreciative, if not entirely capable eye.
If you’re feeling disappointed that you can’t see these differences in bird feathers, do not fear. There is still an incredible array of amazing things happening with the bird feathers that we can see.
Hummingbirds, specifically our resident Anna’s hummingbirds, have a display that is spectacular; whether it is the first time you’ve seen them or the thousandth. The males have a patch of feathers over their entire head that is iridescent. Depending on the direction from which you see them, the reflecting light and their movements you could see greens, reds, purples and more. As white light, which contains all wavelengths of visible light, hit these feathers, tiny pockets of air and keratin within the feathers cause different wavelengths, and thus colors, to be absorbed, reflected and scattered. This is what allows for the visual treat of iridescence when we are fortunate enough to have an encounter with these sassy wee birds.
I encourage you to take a few minutes each day to notice the natural world around you. Take a deep breath and revel in the invigorating scent of a fir tree, listen for the melody of insects and birds unbothered by our human concerns, soak in beauty all around and most importantly; be kind to yourself and the others inhabiting this world.