The pivotal role of Baja Arizona foodscapes in bee and butterfly recovery.
Go to the produce section in any Whole Foods, AJ’s, or Sprouts in the Tucson area, and at least 237 of the 453 fruits and vegetables found there were brought to you by a now-imperiled fleet of flying pollinators. While scientists and farmers in Baja Arizona were among the first in the country to sound the alarm about pollinator declines, they are also leading the way in on-farm pollinator recovery that may ultimately ensure our own food security.
We can thank the local pollination ecologist Gerald Loper for much of what we know about the causes and consequences of honeybee declines in our region. In 1988, Loper began hiking down Camp Grant Wash near Oracle Road, searching for feral colonies of honeybees—those stashes of hives found in rock crevices, caves, and hollow trunks made famous by Winnie the Pooh. Over the next five years, he located 245 nest sites for honeybees, 100 of which he revisited twice a year through 2009.
Loper, now 89 years old and still active, recalls that he soon began seeing significant changes in the number of sites that the bees were occupying from year to year: “I got pretty good at guessing which ones would be occupied or abandoned. Once in a while, I would even record one being reinhabited.” But he couldn’t have fathomed in 1988 the severity of changes wrought by drought, parasitic mites, and Africanized bees to the feral honey bee populations of the Sonoran Desert.
In 1989, just a year after his survey began, a tracheal mite parasitic on honeybees was recorded in Arizona for the first time. In 1992, varroa mites, another form of deadly parasite, arrived in the Tucson Basin. Then, in 1994, Africanized bees that first had escaped into Brazil were seen in the Rincon Mountains, and along Santa Cruz River tributaries. Suddenly, the pollinator landscape of Baja Arizona was irrevocably changed.
By 1996, only eight of the 208 colonies Loper recorded at nest sites near Oracle in June of 1993 remained alive. As he broadened his survey to include rangelands near Sierra Vista and Mammoth, Loper determined that only about 15 percent of the bee colonies known at the start of the 1990s had survived into the next millennium. Today, the honeybee colonies in Baja Arizona have rebounded to a third to four-fifths of what they were when Loper began his surveys, but we know now that at least 24 other countries worldwide have also suffered significant honeybee and bumblebee declines.
There may be fewer bees left on this planet than at any point in our lifetimes, prompting Loper’s former colleague Steve Buchmann to declare that we are facing a global crisis in pollinator availability. “We have noted disrupted relations between plants and pollinators, diminished numbers of seeds per fruit among rare plants as well as commercial crops, and declining populations of animal pollinators,” he said.
“In our studies along the Mexican border with the United States, only 27 percent of cereus cactuses were pollinated. In one area sprayed with pesticides, only five percent produced fruit. In areas free of agrichemicals, between 60 and 100 percent of the plants would have been pollinated, and between 75 and 100 percent would have borne fruit. Those findings have been echoed the world over, in habitats as dissimilar as the tallgrass prairies of Iowa and the dry Chaco Serrano scrublands of Argentina.”
Honeybee pollination services to agriculture in the United States alone are now valued at around $30 billion a year, but honeybees are but one of many species of pollinators whose populations have plummeted over the last quarter century. Bumblebee and monarch butterfly populations have also reached all-time lows. These declines have prompted recent outcries from everyone from farmers and beekeepers to President Obama and Secretary of Agriculture Tom Vilsack.
Baja Arizona’s prevailing drought over the last 15 years has not helped honeybees nor their keepers. Jaime de Zubeldia of ReZoNation Farms is both a natural beekeeper and a grower of vegetables and fruits, and said that the drought has many impacts on his managed bees and nearby swarms: “We started tracking bloom times relative to colony buildup since 2010 or 2011. This year, warmer weather [earlier in winter and spring] resulted in earlier bloom times by about three weeks. So far, our notes from year to year show a gradual warming extending earlier into the year as time goes on. This means longer summers that we need to adjust to.”
De Zubeldia added that drought and heat can also trigger abandonment of former nest sites, swarming, and colonization of new areas by bees. “This year we recorded just over 50 swarms as a result of much earlier than expected warmer weather. If it had been a normal year, hive expansion would have taken place well in advance, avoiding swarming activity that affects the total honey yield and profits.”
Remarkably, the hive survival rate at ReZoNation Farms has held at around 95 to 97 percent as measured by those colonies that over-winter successfully. Many beekeepers across the Southwest are now suffering losses of 25 to 30 percent, which make their beekeeping operations unsustainable. There is much to be learned from Jaime and Kara’s successes; twice a year, they hold a natural beekeeping school at their farm in Marana, including an upcoming course this October. Among their time-tried strategies for success are:
- Keeping the immune defenses and digestive tracts of their bees in top condition by shielding them from exposure to neonicotinoid pesticides.
- Growing bee forages or locating colonies in habitats with abundant native flowering plants rather than offering supplemental feeds such as sugar syrups or soy protein patties.
- Breeding queens from regionally adapted, disease resistant stock from their own best hives and discouraging drone production from poorly producing hives.
While beekeepers like Kara and Jaime de Zubeldia are doing their part for pollinator recovery by promoting bee health, others are restoring flowering plant diversity to migratory pollinator corridors running across Baja Arizona’s farms and ranches. In collaboration with the University of Arizona’s Sustainable Food Systems Program, Borderlands Restoration has been helping farmers, orchard keepers, vineyard managers, and ranchers with pollinator habitat restoration on private lands since 2012. At least 10 farms, ranches, and community gardens have recently been certified as Pollinator-Friendly Habitats or Monarch Waystations in Baja Arizona for their efforts to provide both nectar sources and larval host plants for monarchs and other butterflies, squash and gourd bees, carpenter bees, blue orchard bees, hummingbirds, and nectar-feeding bats.
The native plants that do best at attracting and sustaining migratory pollinator populations are being featured for sale at the Borderlands Restoration nursery in Patagonia, a town that recently declared itself the Pollinator Capitol of the United States. The city boasts that within just a few miles of the Pollinator Gardens on its village green, naturalists have documented more than 600 species of native bees, 16 species of hummingbirds, 150 or more butterflies, and two nectar-feeding bats.
Nearby, Southwest Monarch Study’s Gail Morris and others have been tagging monarchs in the Canelo Hills and learning that that butterflies from this area migrate both to the California coast and to the mountains of Michoacan, Mexico. It is likely that the presence in Santa Cruz County of 19 different kinds of milkweeds—perhaps more than in any other county in the country—have much to do with making the Canelo Hills a butterfly mecca.
Back in Tucson, a new coalition of pollinator researchers, conservationists, educators, and habitat restorations have come together, calling themselves the Southern Arizona Community of Practice for Pollinator Habitat Recovery. The goals of this group include the design and implementation of recovery plans for most groups of imperiled pollinators residing in or migrating through Baja Arizona. The University of Arizona’s Laura López-Hoffman is also helping guide a transborder monarch butterfly recovery plan mandated by an agreement between President Obama, Canadian Prime Minister Stephen Harper, and Mexican President Enrique Peña Nieto at their historic “post-NAFTA” summit in Toluca, Mexico, this last February. Since then, Arizonans have participated in a White House Pollinator Summit in Washington, D.C., and a Trilateral Meeting on Endangered Species and Ecosystems in Queretaro, Mexico.
In the late 1960s, Arizona farmers themselves successfully lobbied for a state ban on the use of DDT in farmlands to protect pollinators from excessive spraying that had caused millions of dollars of crop losses in melons and other crops. Their efforts preceded by several years the national initiative, in honor of Rachel Carson’s Silent Spring legacy, to ban DDT on American croplands and to establish the Environmental Protection Agency. Wouldn’t it be fitting if Arizonans again assumed national leadership in protecting our pollinators not only from toxins, but also from habitat loss, climate change, pests, and diseases? With such tireless innovators in our ranks, Baja Arizona is positioned to offer some of the solutions required to deal with the global pollinator crisis. ✜
Pollinators Bees / Illustrations by Robert J. Long
Gary Paul Nabhan is based at the University of Arizona Southwest Center, where he facilitates pollinator recovery alliances. Learn more at makewayformonarchs.org. He is the co-author of Stitching the West Back Together (University of Chicago Press, 2014).