Category Archives: Wild Garden Helpers

How to Really Save the Bees

agapostemon-virescens-in-ground-nest-3
A metallic green bee, identified by researcher Christy Stewart as Agapostemon virescens, emerges from a ground nest in her Wisconsin backyard. Most of North America’s 4,000 or so native bee species raise their young underground. Others are largely cavity-nesters, laying eggs in wood, twigs, and other materials. (Photo above by Christy Stewart. Featured image, top, by Megan E. Leach)

In a few short months, the sweet scent of thawing soil will have me searching under trees, along streams and in gardens for new life peeking into the frosty air. During the dark days of winter, it’s hard to imagine anyone more excited about spring’s brave first blooms.

But just below ground, creatures on a more important mission than mine will be getting ready to greet the plants, too. Mother bumblebees will emerge from leaves to start new colonies, timing their arrival for the flowering of Dutchman’s breeches and Virginia bluebells. Ground-nesting bees will dig through blankets of dirt to indulge refined tastes: Andrena erigeniae will turn to her exclusive culinary supplier, spring beauty flowers, to make pollen cakes for her babies; Habropoda labiorosa will get her groceries from blueberries, redbud trees, oaks and Carolina jessamine. Cavity-nesting bees—who’ve waited out the cold in logs and twigs—will also join the party.

As we awaken from our own kind of hibernation, many of us will walk by these animals without even noticing them. Though everywhere in the landscape, they occupy little space in the cultural mindset, much to the chagrin of scientists working to save them. If he had to pick one fact more people should know about North America’s 4,000 wild bee species, says conservation biologist Rich Hatfield of the Xerces Society for Invertebrate Conservation, it would be this: “That they exist.”

Image of Andrena erigeniae on spring beauty
Andrena erigeniae, a kind of mining bee, is a pollen specialist on the flowers of spring beauties (Claytonia virginica). (Photo by MaLisa Spring)
Image of bee nests by MaLisa Spring
Think these are anthills? Think again. They are the nests of native mother bees. (Photo by MaLisa Spring)
Image of bee emerging from ground nest
Unmulched areas near plants can provide ideal nesting habitat for many ground-nesting bees. (Photo by MaLisa Spring)

Their solitary nature, hidden nests and often diminutive sizes have made most bees historically difficult to observe, even for scientists. “Go back 20 years,” says biologist Olivia Messinger Carril, coauthor of The Bees in Your Backyard, “and the number of people that studied bees could be counted on your hands and your feet, total.” The obscurity of native pollinators also stems from a disproportionate focus on a single species imported from Europe 400 years ago. “Most people, when they think about bees, they have an image that pops into their head, and that’s the honeybee,” says Hatfield.

Image of honeybee on frost aster
Honeybees are important pollinators and deserve our help, but knowledge of their plight has tended to obscure the needs of the many other bees who don’t live in hives. (Photo by Nancy Lawson)

Critical to current agricultural systems that manage hives for food crops, the domesticated honeybee dominates headlines as beekeepers struggle to stop mass die-offs blamed on disease, mites, habitat loss and pesticides. But just as hard at work in our forests, fields and gardens are mason bees, mining bees, bumblebees and others whose services have produced fruits and seeds for countless animals—including people—for millennia. They, too, are at risk, dependent on ever-shrinking habitat to accommodate lifestyles that bear little resemblance to those of their captive-raised cousins.

Instead of adding hives, which may further increase competition for floral resources and transmit disease, add habitat.

The needs of wild bees are so different that, as some experts say, raising honeybees to save pollinators is like raising chickens to help birds. Though many homeowners respond to “save a bee” campaigns by purchasing hives, the practice is unlikely to improve honeybee health and may harm other bees by increasing competition for floral resources and exacerbating the risk of disease transmission. In the turf-dominated landscapes of suburbia, native bees need all the flowers they can find.

To benefit these special creatures as well as many other animals,  take these steps to enhance your backyard habitat:

Plant diverse native species and other bee favorites.

While some bees have long tongues to access tubular flowers, those with shorter tongues tend to visit shallower blooms. Many are dietary generalists, but pollen specialists rely on certain species. A succession of native blooms ensures there’s something for everyone. In my mid-Atlantic yard, that means leaving violets for their biggest fan, a mining bee known as Andrena violae, or evening primroses for the Lasioglossum oenotherae, a sweat bee they host. In the Southwest, it means nurturing cacti for Diadasia bees partial to their pollen. Across the continent, asters, goldenrods and sunflowers provide seasonal nourishment in autumn as other flowers wane. Bee experts also recommend supplementing native blooms with herbs and cottage-garden annuals attractive to bees such as hollyhocks, lavender, and zinnias.

Image of squash bees by Megan Leach
Squash bees, or bees in the Peponapis genus, depend on squash flowers and can pollinate them more effectively than honeybees. (Photo by Megan E. Leach)
Image of Melissodes agilis on sunflower
Melissodes agilis visits the Utah backyard of USDA scientist Jim Cane. The species specializes on pollen of plants in the aster family, including sunflowers, where gardeners are most likely to see them. (Photo by Jim Cane)

Set up maternity wards for mother bees.

Mother bees ask for little: Most nest alone in sunny dirt patches left unmulched. Some lay eggs in stalks of goldenrod, elderberry and other plants left standing, including dead or dying trees. Bumblebees, a more social species, colonize grassy tussocks, rodent burrows and other unmowed areas, where fallen leaves also shelter overwintering queens. The less you indulge your urge to “clean up” in the garden, the more you’ll help these hard-working creatures. Let fallen leaves lie, and resist the temptation to add mulch to exposed earth. Leave last season’s leftover stalks wherever you can; if you need to prune, give bee larvae a chance by propping the twigs against a tree or scattering long pieces between plants in your garden.

Lay down your weapons.
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The telltale signs of mother leafcutter bees building their nests appeared on my wild grapevine leaves in Maryland  last summer. (Photo by Nancy Lawson)

Some pesticides contaminate pollen and nectar, and others kill on contact. Before grabbing spray bottles, observe what’s really happening. Holes in roses may be the handiwork of leafcutter bees lining nests with petals and foliage. Instead of treating such phenomena as aggressive acts, be proud that you’re helping generations of bees—and many other animals depending on the incalculable services these unsung heroes provide.

Don’t blink or you’ll miss it! Check out this video of a bee returning to her underground nest by Dr. Jim Cane of the USDA’s Agricultural Research Service in Logan, Utah:

For further information

Specialist bees: About a third of the approximately 450 bee species native to the Mid-Atlantic and Northeastern U.S. are pollen specialists, relying on blooms of plants of a certain genus or even single species. In other regions like the Southwest, that ratio could be even higher. Read more here.

Citizen science: Of the thousands of native bee species in North America, only 46 are bumblebees. But these social creatures are some of our best pollinators. At least a third are thought to be in decline, however, and one hasn’t been seen since 2006. Help these animals and the scientists who study them by joining Bumble Bee Watch, a citizen science program that teaches you how to identify bees as you document sightings in your own backyard and community.

Guidelines for gardeners: One of the photographic contributors to this article, entomologist Jim Cane, has produced helpful guidelines for those interested in creating nesting and flowering habitat. Though some of the advice is specific to Utah, much of it is universal. See Gardening and Landscaping Practices for Nesting Bees and Gardening for Native Bees in Utah and Beyond.

Field guide: With the help of The Bees in Your Backyard and its authors, I’ve already learned to identify bees so tiny they used to look more like flies or wasps to me. Mixed with detailed descriptions of anatomy and lifestyles are fascinating facts about bee behavior and natural histories.

Mini field guide: If Bee Basics: An Introduction to Our Native Bees doesn’t make you fall in love with native bees, nothing will. This lavishly illustrated guide from the USDA Forest Service and Pollinator Partnership provides a gorgeous, empathetic look at everything you never knew about native bees and their lifestyles.

Planting guides: Created with more than bees in mind, these region-specific Selecting Plants for Pollinators guides from the Pollinator Partnership briefly explain why different kinds of blooms attract different species. PDFs tailored to 24 regions in the U.S. and Canada help gardeners learn how to plant for bees, butterflies, moths, beetles, flies, hummingbirds and bats.

For more tips on working with nature in your garden, check out my new book, The HumImage of Humane Gardener book coverane Gardener: Nurturing a Backyard Wildlife Habitat.

A shorter version of this article originally appeared in my Humane Backyard column in the January/February 2017 edition of All Animals magazine. A special thanks to MaLisa Spring, Megan E. Leach, Christy Stewart and Jim Cane for generously sharing their spectacular photos and video.

 

Spirit of the Evening Sky

Image of spectacled flying fox
Australia’s spectacled flying fox is one of about 1,300 bat species worldwide. (Photo by Jurgen Otto/Creative Commons)

They inhabit the ruins of a 14th-century empire in Africa, cling to 800-year-old cliff-side dwellings in Arizona, forage in old Indian temples and European churches, and occupy the decidedly less grand crawl spaces of our modern homes.

As the only true flying mammals, the world’s 1,300 bat species know how to get around. While some have esoteric lifestyles—roosting in unfurled banana leaves or tents carved from rainforest foliage—many are less specialized, building a life wherever people have already made their mark on the land. Now adapting to the latest artifacts of human empire, bats often trade their traditional caves and trees for abandoned mines and cozy attics.

Image of Honduran white bats
A plant to call home: Tiny Honduran white bats, whose lengths average 3.7 to 4.7 centimeters, create a perfect tent for roosting by cutting the veins of Heliconia leaves. (Photo by Tim Carter, courtesy Organization for Bat Conservation)

Though resilient, these animals—who account for a quarter of all mammal species—are in decline worldwide. The pace of development is much faster than it was in the days of ancient temple-building, with chainsaws destroying natural roosting sites, pesticides decimating food supplies, and wind turbines killing bats outright. Humans have even learned how to take to the skies themselves, their long-distance flights paving the way for the speedy transport of pathogens like the one that has killed nearly 7 million bats in North America in the past 10 years.

Image of little brown bat
Biologists band and track little brown bats as part of an effort to learn more about the devastating white nose syndrome. (Photo by USFWS/Ann Froschauer/Creative Commons)

The fungus responsible for white nose syndrome likely arrived on the clothing or gear of cavers, scientists or other visitors to hibernation sites. Not known to affect bats where it originates in Europe, here the pathogen causes bats to awaken too early from winter slumber, depleting their limited fuel reserves. Transmission is so rapid that little brown bats could be gone from the eastern U.S. by 2020.

“In just a couple of decades, we’re looking at going from an extremely common species to an endangered or nearly extinct species,” says Rob Mies, executive director of the Organization for Bat Conservation. White nose syndrome will likely affect more than half of the 47 bat species in the U.S. and Canada. “For us bat biologists, it’s just absolutely devastating.”

Their vanishing would be ecologically disastrous. Most bats are insectivorous, consuming up to 120 percent of their weight daily and contributing an incalculable amount of insect control services.

Image of Mexican long-tongued bat
Mexican long-tongued bats are important pollinators of agave and cacti. (Photo by USFWS/Creative Commons)

Some are pollinators, fruit eaters, and seed dispersers, playing an important role in forest regeneration and even in happy hours.  “When you go to a Mexican restaurant and you order chips and guacamole and a margarita, those things aren’t going to exist without bats,” says Mies. “Bats pollinate avocado trees, and they also protect corn—they’re one of the most important predators of the corn earworm moth. And they’re the only pollinators of the agave that we make tequila from.”

While certain locations—like the Congress Avenue Bridge in Austin, Texas—are known for harboring these quiet creatures of the night, bats are everywhere; we just don’t realize it. “When people are outside and bats are flying over their head, they don’t know they’re bats,” says John Griffin, director of the HSUS urban wildlife solutions program. “They think they’re birds.”

Image of bat at the Cape Wildlife Center
Wildlife rehabilitators take great care to avoid damaging the delicate wings of bats. (Photo by Heather Fone/The HSUS)

More closely related to whales than birds, bats can see but primarily rely on echolocation, emitting high-frequency sounds to find prey. Their wingspans belie their size; even a big brown bat is not so big at all, weighing less than an ounce, notes Deborah Millman, director of the Cape Wildlife Center in Massachusetts. Bats are so diminutive that rehabilitators feed them with tweezers and wear special gloves to protect both the handlers and the bats’ paper-thin wings.

In a retrofitted barn attic situated near night lights to attract insects, recovering bats at the Cape facility also feed themselves. Before the habitat was built, “we had one bat who was literally walking to the food dish,” says Millman, but now flying patients can build cardio strength critical to life in the wild. “We’re really bat-happy here. People are afraid of them, but they do a lot of good.”

Follow these tips to create safe spaces for these delicate creatures on your own property:

Plant a Bat Garden.
Image of bat garden sign
Hang a sign to encourage others to join the cause. (Photo by Nancy Lawson)

Masters of disguise, bats don’t reveal daytime whereabouts; red bats hanging from trees look like decaying leaves, Indiana bats blend into loose bark of dead and dying trees, and hoary bats’ coats mimic lichen. To help them evade predators and find roosting opportunities, leave tree snags in place and plant hickories, maples, oaks, spruces, pines, beeches, gums, and other species that will provide many nooks and crannies in the bark and trunks.

Bats eat moths and other nocturnal fliers attracted to flowers that open at sunset, such as evening primrose, or blooms that never close, such as wild bergamot. In many regions, fall is a great time to plant; find lists of recommended species, a bat garden planting guide, and bat habitat signs from the Organization for Bat Conservation.

Install a Bat Hotel.

Even if designed according to building codes specified by experts, a bat house may sit empty for years. But when an ice storm topples the preferred real estate of dead ash trees down the road, your hospitality will be well-received. “Bats aren’t going to leave a perfect place,” says Mies, “but when they need to relocate, that’s when the bat house is available.” Create your own backyard bat house with these helpful blueprints and guidelines.

Evict Humanely.

Tiny crevices leading to attics are invitations to bats. “They can virtually flatten themselves and get into really tight spaces,” says Griffin. To remove them safely, he covers gaps with a temporary fiberglass window screen open at the bottom. Called a “check valve,” the method allows bats to exit but not reenter; once they’re gone, openings can be sealed. For more information about humane eviction and exclusion methods, visit the websites of Bat Conservation International and the Humane Society of the United States.

Featured image of Rodriguez fruit bat: Alfred Viola, Northeastern University, Bugwood.org.

The original version of this article was published in the September-October issue of All Animals magazine.