Birds, Butterflies, Bees and Their Flowers

 In all of nature there is no more perfect partnership between animals and plants than that which exists between flowers and their pollinators. Of course flowers are the primary mechanism by which plants reproduce sexually; except for wind pollinated forms, their colors, forms and alluring scents are designed solely to attract specific pollinators which are best able to efficiently fertilize the embryonic seeds. So often we fail to comprehend this overall evolutionary plan when we appreciate flowers only as they appear to humans. So consider for a moment how some flowers are designed and thus co-evolved and specialized to attract birds or insects.  .


The classic hummingbird flower is illustrated by the coral honeysuckle (Lonicera sempervirens). It has a long, narrow tubular red flower that hangs down. This restricts access to the nectar reward primarily to hummingbirds or their insect equivalents, the hummingbird sphinx moths which also hover, and some butterflies which can hang onto the flower. While it might be possible for bees or other birds to land on the vine and bite the base of the flowers to steal the nectar, this is not an easy task. Indeed it appears that bumblebees primarily see in the UV, blue and green spectral ranges and thus are not attracted to red flowers. 

The classic bumblebee flower is illustrated by the photo of a bee on a wild indigo plant (Baptisia australis). The flower is blue with a short corolla tube allowing the bee with its bulky body and short tongue to hold onto the flower and to easily reach the nectar reward. 

Butterflies tend to be attracted to red, yellow or orange flowers and with their long tongues they can feed on a wide variety of flower types. This photo shows a spicebush swallowtail butterfly on a milkweed (Asclepias tuberosa) which appears to be brightly colored to attract butterflies. Note also that one of the swallowtail extensions on the hindwing (likely designed to be a false head to deflect attacks from the real head) has been bitten off, perhaps by a bird. This butterfly is also colored very similarly to the poisonous pipevine swallowtail, likely as a type of protective mimicry. 

As you develop your skills in interpreting why flowers look as they do, consider the strange moonflower morning glory (Ipomoea alba), which emerges at night, is white, and has a very long corolla tube which would appear to exclude all pollinators except night-flying sphinx moths with extremely long tongues. This provides an example of the most specialized of flowers which appears to cater only to a few species of pollinator.  


Thus flowers with characters that attract the most effective pollinators have an advantage in reproduction and produce more progeny.  I think you will find that this evolutionary perspective on the world of flowers and their pollinators will deepen and enrich your enjoyment of flowers. 

Bill Dunson Englewood, FL, and Galax, VA