A Hypothesis Concerning the Prevalence of Red Coloration in California Hummingbird Flowers

Abstract

The prevailing view that the prevalence of red floral colors in humming-bird-pollinated plant species of the California and western American flora is related to a preference for red by hummingbirds is not supported by experimental evidence. An alternative hypothesis is presented relating common red coloration to the nomadic and migratory habits of the hummingbirds in this region. Rapid recognition of hummingbird flowers by hummingbirds which frequently enter new feeding territories is selectively advantageous to the plants and their bird pollinators; a common floral color displayed by the different plant species facilitates this quick recognition. Common red coloration is an instance of a situation in plants comparable to the phenomenon of Mullerian mimicry among animal species.