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A Pollinator’s Job Description and Why We Should All Care About Them

Pollination 101

Pollinators are not only beautiful but are also integral to our food system. Unfortunately, pollinators are in trouble.

Fig. 1 Plants can’t move around to have sex; they employ pollinators to do it for them. source: Wikimedia Commons

A Pollinator’s Job

The stationary life of plants presents them with several major complications. Not only can they not escape herbivory (being eaten by animals), but they also have a hard time mating with other plants. To overcome this challenge, plants have evolved several methods to mate at a distance. For example, conifers and grasses rely on wind carrying their pollen grains (male genes) across large distances. However, this strategy is very inefficient. The probability of any single pollen grain landing in the female receptacle of another individual is infinitesimally small. Ever notice there are more kinds of flowering plants than conifers? That is because flowering plants have evolved a more efficient method to disperse their genetic material. Flowering plants, being immobile, rely on insects or other animals to carry their pollen to the stigmas of other plants. This is the way most flowering plants reproduce [1].

Fig. 2 In addition to the European honey bees that we all know, there are a multitude of native pollinators that do the same job, if not more efficiently. Credit: Steve Buchanan

Fig. 3 Although honey bees and bumblebees are well known pollinators, birds, bats or butterflies can also pollinate plants. Credit: Steve Buchanan

Pollination is most aptly referred to as the movement of pollen from one flower to another, typically through bees and other insects. However, pollinators don’t do this for free. Plants must offer a reward for the pollinator to visit and carry their genes off to another flower. Rewards offered can just be sugary nectar and protein-rich pollen. Some plants offer scents used by pollinators to attract mates and sometimes, plants just trick male bees into thinking they are female bees. Although paying pollinators for their services is not cheap, it is far more efficient than other methods of reproduction such as wind-mediated transport of pollen. This mutualism between flowering plants and pollinators is so strong that some plants cannot reproduce at all without being visited by a pollinator, and some pollinators feed exclusively on pollen and nectar.

Why We Should Care

Over the past decade or so there has been an explosion of interest in pollinators, whether they are honey bees, bumblebees, or monarch butterflies. Public interest has sparked scientific and conservation efforts for our oft-ignored flower-loving friends. So, why the sudden rise in interest and why should people continue to care about them?

Although small and seemingly unimportant, pollinators are essential to humans. A large fraction of our agriculture is dependent on these small insects; 87 of the 115 most important crops are pollinated by animals [2]. Most fruits on our tables are pollinated by bees: the plum tomato in my sandwich, as well as the half eaten apple on your desk. The problem is that pollinators are currently under severe stress. Honeybees face colony collapse disorder (CCD), bumblebees are infected with aggressive diseases, and there is a lack of quality habitats left for pollinators altogether. Some studies have shown that in certain places up to half of bee species have disappeared over the last hundred years [3]. All of these factors, along with others, have triggered a rapid decline in pollinators–a cause of great concern for farmers, beekeepers, scientists, and the general population [3,4].

So what does all of this mean? Even if you have no interest in bees or butterflies, you will still probably suffer the consequences, most likely by paying a lot more for fruits and vegetables when you visit the supermarket. We can all help conserve pollinators by planting more pollinator-friendly flowers in our gardens, planting more hedgerows, and spraying less pesticides. If you want to find out more about how to help conserve pollinators, or just about pollination in general, visit the USDA’s Natural Resources Conservation Service.

References

[1] Willmer, Pat. Pollination and floral ecology. Princeton University Press, 2011.

[2] Klein, A. M., Vaissiere, B. E., Cane, J. H., Steffan-Dewenter, I., Cunningham, S. A., Kremen, C., & Tscharntke, T. (2007). Importance of pollinators in changing landscapes for world crops. Proceedings of the Royal Society of London B: Biological Sciences, 274(1608), 303-313.

[3] Allen-Wardell, Gordon, Peter Bernhardt, Ron Bitner, Alberto Burquez, Stephen Buchmann, James Cane, Paul Allen Cox et al. “The potential consequences of pollinator declines on the conservation of biodiversity and stability of food crop yields.” Conservation Biology (1998): 8-17.

[4] Burkle, Laura A., John C. Marlin, and Tiffany M. Knight. “Plant-pollinator interactions over 120 years: loss of species, co-occurrence, and function.” Science 339, no. 6127 (2013): 1611-1615.

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