Any major disturbance of either the plant community or the pollinators can result in a decline, perhaps catastrophi- cally, of the other group, with a possible cascading effect reaching to the animals dependent upon the plants directly for food, or indirectly by supporting prey. Specialists are adapted in structure, behavior, and periods of activity to exploit efficiently one, or a few, species of flowering plants. Often a plant is also highly dependent on its specialist pollinators to be fertilized and set seed. Generalist pollinators visit a wide variety of flowers and usually are not dependent on any one species for their success. Generalist pollinators, like specialists, typically pollinate the flowers they visit, but they usually are not as efficient as specialists, and sometimes simply rob the floral nectar without pollinating the flower.
Honeybees are native to Africa and Western Eurasia.
Historically, Organ Pipe Cactus National Monument was a complex of subtropical thorn-scrub and other communities that was pollinated primarily by specialist pollinators. Honey bees first arrived in the environment a few hundred years ago with colonizing Europeans, who brought with them their honey bees. The effect of these feral European honey bees on the monument is unknown because they arrived before any floral surveys were conducted. There is also uncertainty about their impact because European honey bees do not seem to develop populous and abundant colonies in the harsh climate of the monument. These bees are much more vigorous competitors in tropical climates than their feral European cousins and might adapt better to the climate of Organ Pipe Cactus.