Pollination By Animals
In general, pollination by insects and other animals is more efficient than pollination by wind. Typically, pollination benefits the animal pollinator by providing it with nectar, and benefits the plant by providing a direct transfer of pollen from one plant to the pistil of another plant. Angiosperm flowers are often highly adapted for pollination by insect and other animals.
Each taxonomic group of pollinating animals is typically associated with flowers which have particular characteristics. Thus, one can often determine which animal pollinates a certain flower species by studying the morphology, color, and odor of the flower. For example, some flowers are pure red, or nearly pure red, and have very little odor. Birds, such as hummingbirds, serve as pollinators of most of these flowers, since birds have excellent vision in the red region of the spectrum, and a rather undeveloped sense of smell. Interestingly, Europe has no native pure red flowers and no bird pollinated flowers.
Some flowers have a very strong odor, but are very dark in color. These flowers are often pollinated by bats, which have very poor vision, are often active during the night, and have a very well developed sense of smell.
The flowers of many species of plants are marked with special ultraviolet absorbing pigments (flavonoids), which appear to direct the pollinator toward the pollen and nectar. These pigments are invisible to humans and most animals, but bees' eyes have special ultraviolet photoreceptors which enable the bees to detect patterns and so pollinate these flowers.
The American Horticultural Society. The American Horticultural Society Encyclopedia of Plants and Flowers. New York: DK Publishing, 2002.
Gould, S.J. The Panda's Thumb. New York: W. W. Norton, 1980.
Judd, Walter S., Christopher Campbell, Elizabeth A. Kellogg, Michael J. Donoghue, and Peter Stevens. Plant Systematics: A Phylogenetic Approach. 2nd ed. with CD-ROM. Suderland, MD: Sinauer, 2002.
Peter A. Ensminger