Too Many of the Birds, Bees, and Butterflies That Pollinate Crops Face Extinction
There are an estimated 2.74 million honeybee colonies kept by beekeepers in the United States. It’s a number that, for much of the last decade, has been the subject of much consternation each spring, when researchers announce how many colonies were lost—died off—over the past winter. The numbers have been high, and persistently so, with total annual losses hitting 45 percent in 2012–13, a particularly bad year. This has led to some new terms: colony collapse disorder, pollinators, and neonicotinoids, to name a few. With a third of fruit and vegetable crops depending on pollinators, bees regularly dying in droves, and pesticide use increasing, it can seem like honeybees are the only things keeping us fed—and that they might soon go away altogether.
The relationship among bees, other pollinators, and the food supply is indeed a vital one, but it is far more complex than pitting one bee—Apis mellifera, the European honeybee—against one class of pesticides, such as neonics. Take the new report released Monday by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (which functions much like a United Nations for biodiversity issues) looking at the plight of pollinators and how their decline puts the global food supply at risk.
One of the major takeaways from the study has nothing to do with honeybees but rather the 20,000 wild bee species found around the globe, which also contribute significantly to pollinating food crops. According to the report, more than 40 percent of invertebrate pollinators—wild bees and butterflies in particular—are facing extinction. Similarly, 16.5 percent of vertebrate pollinators (bats, birds, and the like) are threatened by extinction.
While honeybee declines are worrisome, the species itself is by no means at risk of being wiped out. The annual loss stats may be stark, but beekeepers hedge against the die-offs, producing additional hives to replace those that don’t make it through the colder months. A less commonly reported stat in stories about bee losses is the overall population of managed honeybees in the United States, which has remained more or less stable in recent years. The same cannot be said for wild bees, of which there are 4,000 species in the U.S.
“Habitat loss, pesticide usage, bee disease, and climate change are the major threats on wild bee populations,” Insu Koh, a postdoctoral researcher at the University of Vermont’s Gund Institute for Ecological Economics, wrote in an email. (Koh was not involved in the new assessment.) “Our recent national study projected wild bee declines in 23 percent of the contiguous U.S. between 2008 and 2013.”
The study Koh worked on, published by Proceedings of the National Academy of Sciences in December, is one of the latest to focus on native bees and their unwitting contribution to the global harvest that relies on pollinators—estimated in the new IPBES assessment to be worth as much at $577 billion. While bumblebees and butterflies are showing up in places like almond orchards and watermelon fields for the flowers, they have a significant effect. A 2013 study of wild pollinators found that native bees, butterflies, and other nonhoneybee species were twice as effective as their domesticated counterparts at pollinating more than 40 crops. Not only did these wild species do better “work,” but the managed hives didn’t replace the labor of native species—it only added to what the wild pollinators accomplished.
The new assessment states that the role of pesticides like neonics in pollinator losses remains unclear—but less so for wild bees. According to a press release, “A pioneering study conducted in farm fields showed that one neonicotinoid insecticide had a negative effect on wild bees, but the effect on managed honeybees was less clear.” Another threat, said IPBES, is the erosion of indigenous farming practices, which, in some regions, predate contemporary obsessions with “sustainability” by centuries, if not longer.
However, contemporary farmers and agricultural researchers are considering many options that could help make farmland a more welcome place to pollinators—honeybees, butterflies, and native bee species alike. Be it native hedgerows planted alongside orchards in California or strips of native prairie interspersed with row crops such as corn and soy in the Midwest, there are ways of making a farmed landscape look more like home to the ag industry’s tiny, vital workforce—but few, if any, have gone from being experimental to the status quo.
“Pollinators are important contributors to world food production and nutritional security,” Vera Lúcia Imperatriz-Fonseca, who cochaired the assessment, said in the statement. “Their health is directly linked to our own well-being.”