University Extension agent discusses promoting positive habitat for pollinatorsWritten by Natasha Wheeler
“Worldwide, there are about 20,000 species of bees,” notes UW Extension Educator Tina Russell.
There are nearly 4,000 species of native bees in the United States.
“Bees are important pollinators,” Russell continues. “They actively collect nectar and pollen. Nectar is their energy source, and pollen is their protein.”
About one in three mouthfuls of food, either bites or drinks, are a result of pollination.
“If we didn’t have pollinators, our diet would be very minimal and less varied,” she explains.
Scientists and researchers predict that wind-pollinated plants, such as grain crops, would still persist as a food supply without pollinators, but there would be much less variety in our diets.
“The estimated dollar value of pollinated crops is $217 billion, worldwide,” she comments.
Pollinators include bats, birds, wasps, flies, beetles, butterflies and even lemurs.
“Lemurs are animals that pass plants and accidentally pollinate other flowers,” Russell says.
Physical and behavioral characteristics of bees make them some of the most efficient pollinators in the ecosystem.
“Bees have adapted to the flowers. They are able to fit inside and move pollen around to other flowers,” notes Russell.
Bees also have hairy bodies that trap pollen on their legs, backs and abdomens.
“A lot of bees also have the ability to buzz pollinate. They crawl into the flower and use their leg muscles to vibrate the flower and shake the pollen loose,” she says.
Although honeybees do not have this ability, bumblebees and many native species use buzz pollination.
“Many species have a generalist feeding pattern, which means that they visit a lot of different flowers,” Russell adds.
Although some species are specialists that only visit specific plant types, many of them contribute to pollination on a large, broad scale.
“They also have flower consistency on foraging trips,” she says.
This means that insects may target a specific plant when they leave the hive or nest. After they return to drop off the pollen and nectar, they may target a different plant on the next trip.
“Flower consistency is something characteristic of bees, and it really helps with pollination,” she explains.
Studies have shown a noticeable decline in commercial honeybee populations, which are European bees that are not native to the U.S.
“Populations have been declining since about 1980, and crop production has been declining due to a lack of pollination since about 1990,” Russell comments.
There were approximately 5.9 million honeybee hives in 1947, and there are only about 2.5 million today.
“These are just honeybees or commercial bees managed in croplands. This doesn’t account for native bees,” she adds.
There has been less research concerning native species, but evidence shows that their populations may be threatened as well, and researchers have identified a number of different factors.
“One of the biggest impacts is habitat loss,” says Russell.
Large bees, which travel further than smaller species, cover foraging ranges from one to three miles.
“It is hard for them when they have habitat loss, fragmentation and fewer nesting options,” Russell continues.
Scientists believe that climate change and pesticides may also be contributing factors.
To encourage increased populations, Russell notes, “There are four things we can all do.”
Learning to recognize pollinators and their habitat, protecting habitat, providing new or enhancing existing habitat and adapting long-term management practices are Russell’s suggestions for promoting pollinators.
“Generalists, like the honeybees and bumblebees, have longer lifespans and can live four to five months,” she says. “We want to plant plants that bloom throughout the growing season.”
Specialists, or bees that concentrate on specific plant types, may only harvest pollen and nectar for five or six weeks.
“We will focus on different plants and different bloom periods,” she continues in reference to different bee varieties.
Nesting requirements are another habitat consideration, as some bees nest in the ground and others prefer a cavity or wood.
“It depends on what kind of bees we have and what kind we want to attract,” she says.
Leaving sandy, uncovered dirt patches attracts some species, while green grass and shrubbery attracts others.
“If we have some old standing trees in our yard, we can drill holes in them to create habitat,” she suggests, “or if there is a place where woodpeckers have been and we leave that alone, it is beneficial for bees.”
More attractive plant species include those in the buckwheat family, lupine, roses, apples and carrots.
“A lot of bees also like herbs such as rosemary, thyme and mint,” Russell adds.
On the farm, hedgerows, windbreaks, native plants and weeds such as clover are beneficial to native bees.
“If we are able to use green manures or ground cover, these provide erosion control as well as food for pollinators,” she describes.
She also encourages allowing for riparian buffers along streams.
“This is good for erosion control, water quality and the pollinators,” she adds.
Reducing pesticides and herbicides, providing a diversity of agricultural and native plants and reduced mowing can also encourage increased populations.
“Our farming and ranching practices affect pollinators. Some of them we can’t avoid, but there are some things we can do to promote positive habitat for pollinators,” Russell says.
Tina Russell spoke at Fremont County Farm and Ranch Days in Riverton on Feb. 12.