Pollinator Color Preferences
The process of flower pollination begins when an insect, bird or bat in search for food
settles on a flower. It sips nectar from it while pollen sticks to its body. As it flies off in search
for more food, it settles on a new flower, and in the process, pollen from the last flower rubs
off onto the new one. With each landing on a flower, pollination occurs.
Plants have a number of different means to attract pollinators, with bright, showy colors being
one of the most common ways to maximize their visual effect. Flowers, in essence, are attention
getters. They are like advertisement signs for pollinators. In order for plants to entice pollinators,
they must first offer their favorite foods: nectar and protein.
Since most pollinators fly, the colors of a flower must attract them, therefore, the brighter the flowers,
the more likely it will be visited.
There is an almost bewildering diversity of flower colors and color patterns in flowering plants with
colors spanning the entire color spectrum of human and pollinator vision. The diversity of flower
colors is largely shaped by the interactions with pollinating animals through the process of natural
When angiosperms (flowering plants with seeds developed in the plant ovary) branched
off from gymnosperms (seeds produced in unisexual cones) on the evolutionary
tree, around 200 to 240 million years ago, flower color was co-opted as a way to attract insect pollinators.
Subsequently, anthocyanins in the plants began producing purple and blue colors in addition to red.
Other pigments like carotenoids also arose.
Bees are perhaps the most important pollinator of many garden plants and most commercial
fruit trees. Since bees cannot see the color red, bee-pollinated flowers usually have shades
of blue and yellow. They visit flowers that are open during the day, are brightly colored, have
a strong aroma or scent, and have a tubular shape, typically with the presence of a nectar
A nectar guide includes regions on the flower petals that are visible only to bees, and not to humans.
It helps to guide bees to the center of the flower, thus making the pollination process more efficient.
Flies are attracted to flowers that have a decaying smell or an odor of rotting flesh. These flowers,
which produce nectar, usually have dull colors, such as brown or purple.
Butterflies, such as the monarch, pollinate many garden flowers and wildflowers, which usually
occur in clusters. These flowers are brightly colored, have a strong fragrance, are open during
the day, and have nectar guides to make access to nectar easier. As a general rule, flowers that
are white, pink, purple, red, yellow and orange attract the most butterflies.
Moths pollinate flowers during the late afternoon and night. The flowers pollinated by moths are
pale or white and are flat, enabling the moths to land. The shape of the flower and moth have
adapted in such a way as to allow successful pollination.
Bats are attracted to flowers that are usually large and white or pale-colored. Thus, they
can be distinguished from the dark surroundings at night. The flowers have a strong, fruity, or
musky fragrance and produce large amounts of nectar. They are naturally large and wide-mouthed
to accommodate the head of the bat.
Flowers visited by birds are usually sturdy and are oriented in such a way as to allow the birds to
stay near the flower without getting their wings entangled in the nearby flowers. The flower typically
has a curved, tubular shape, which allows access for the bird’s beak. Hummingbirds are attracted
to brightly colored flowers, including yellow, orange, pink and purple, but they are attracted to red
more than any other color, as red seems to be an indicator of food to these small birds.