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Botany Greenhouse
The Agents of Evolution - Pollination Syndromes - BirdBird pollination (Ornithophily)
Bat, Bee, Beetle, Bird, Butterfly, Fly, Moth, Snail&Slug, Water and Wind Some birds regularly visit flowers to feed on nectar, floral parts, and flower-inhabiting insects; many of these birds also serve as pollinators. In North and South America, the chief bird pollinators are humingbirds. In other parts of the world, flowers are visited regularly by representatives of other specialized (bananaquits, flowerpeckers, flowerpiercers, honeycreepers, honeyeaters, lorikeets and sunbirds) birds.
Although bird flowers have a copious thin nectar (some even drip with nectar when pollen is ripe), they usually have little odor, which is a corollary of the fact that the sense of smell is poorly developed in birds. However, birds do have a keen color sense (much like our own), so most bird flowers are colorful with red and yellow being the most common.
Bird-pollinated flowers include the red columbine, fuchsia, passion flower, eucalyptus, hibiscus and orchid families. They are large in terms of general size or parts of inflorescences. This features that can be correlated with their importance as visual stimuli and their ability to hold large amounts of nectar.
Bird and other animal pollinators usually restrict their visits to the flowers of a particular plant species, but this is only one factor promoting outcrossing (cross-pollination between individuals of the same species). For outcrossing to result, it is also necessary that the pollinator not confine its visits to a single flower or to the flowers of a single plant. When flowers are visited regularly by large animals with a high rate of energy expenditure, such as birds, hawk-moths, or bats, they must produce large amounts of nectar to support the metabolic requirements of these animals and keep them coming back. On the other hand, if an abundant supply of this nectar is available to animals with a lower rate of energy expenditure, such as small bees or beetles, these will tend to remain at a single flower and, being satisfied there, will not move on to other plants and thus bring about outcrossing. Consequently, in the course of evolotion, flowers that are regularly pollinated by animals operating at a high rate of energy consumption, such as hummingbirds, have tended to evolve flowers in which the nectar is held in tubes or is otherwise unavailable to smaller animals of lower energy consumption. Similarly, the color red is a signal to birds but not to insects since red is outside their visual spectrum. Birds, like ourselves, do not respond very strongly to odor clues. Thus, odorless, red flowers are inconspicuous to insects and do not tend to attract visits by them, an adaptation that is advantageous in view of their copious production of nectar.
Current Accessions:
· Allamanda cathartica - Golden Trumpet {Apocynaceae}
· Calliandra haematocephala - Red Powderpuff {Fabaceae}
· Fuchsia X hybrida - Fuchsia {Onagraceae}
· Heliconia spp. - Lobster Claw {Heliconiaceae}
· Hibiscus rosa-sinensis - Chinese Hibiscus {Malvaceae}
· Impatiens niamniamensis - {Balsaminaceae}
· Mimulus cardinalis - Scarlet Monkey Flower {Veronicaceae}
· Russelia equisetiformis - Firecracker Plant, Coral Plant {Plantaginaceae}
· Strelitzia reginae - Bird of Paradise, Crane Lily {Strelitziaceae}
· Tillandsia ionantha - Blushing Bride {Bromeliaceae}
