My wife and I enjoy gardening for hummingbirds. In an effort to provide them with a source of nectar throughout as much of the year as possible, we provide them a multitude of plants. The list of nectar plants includes such hummingbird favorites as zinnia, Turk’s cap, trumpet creeper, lantana, coral honeysuckle, scarlet sage, lyre leaf sage, red buckeye, hollyhock, columbine and many more. These plants provide us with an ever-changing mosaic composed of different colors. Often when I gaze at this gorgeous setting, I cannot help but wonder what these plants look like through the eyes of the ruby-throated hummingbirds that visit these flowers countless times.
Research conducted by researchers representing the Princeton University Department of Ecology and Evolutionary Biology, Harvard, University of Maryland, Rocky Mountain Biological Laboratory and the University of British Columbia has revealed our ability to see colors pales in comparison with that of hummingbirds. Princeton University Assistant Professor Mary Caswell put it this way, “Humans are color blind compared to birds and many other animals.”
The research discovered hummingbirds appear to be able to detect pure ultra-violet from a combination of colors such as ultra-violet plus red and red as well as ultra-violet plus green from pure green. Ultra-violet plus red and ultra-violet plus green were undetectable to the researchers.
Many scientists believe the reason why hummingbirds are able to see far more colors than us is linked to the fact that a hummingbird’s eye contains four different types of cones whereas humans have but three. The fourth type of cones detect near ultra-violet light (UV). Ultraviolet light is invisible to the human eye.
The ability to detect near UV light is beneficial to hummingbirds because many nectar plants display colors in the near UV light range. Consequently, such plants stand out more to hummingbirds than they do to humans.
I am certain that this research represents another step toward our greater understanding of the hummingbird’s ability to see colors. Wouldn’t it great to catch a glimpse at the colors of the natural world through the eyes of a hummingbird?