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<a href="http://www.nwf.org/nationalwildlife/article.cfm?issueID=129&articleID=1735" eudora="autourl">
http://www.nwf.org/nationalwildlife/article.cfm?issueID=129&articleID=1735<br>
<br>
</a><b>NATIONAL WILDLIFE MAGAZINE<br>
</b>June/July 2009, vol. 47 no. 4<br><br>
The Buzz on Native Pollinators<br>
By Laura Tangley<br><br>
As European honeybees decline, indigenous bees and other pollinating
animals can provide a backupwith a little help from their human
friend<br><br>
<b>WHEN ECOLOGIST</b> Rachel Winfree set out to survey native bees in the
Delaware Valley of New Jersey and Pennsylvania, she was not optimistic
about her results. Not only is the region far from any known hot spots of
bee diversity, such as the U.S. Southwest, “New Jersey is also the most
densely populated state in the country,” says Winfree, an assistant
professor in the Department of Entomology at Rutgers University. “I was
worried that after getting funding and hiring a staff, the project would
turn out to be a waste of time.” <br><br>
Her fears were unfounded. “We found bees everywhere,” says
Winfreethousands of individuals of 46 different species. More
surprising, she and her colleagues discovered that the number of flower
visits by these natives was sufficient to fully pollinate the watermelon
crop on 21 of 23 farms in her study region. <br><br>
Gleaning such data was the goal of Winfree’s work. As European honeybees
decline in a mysterious phenomenon known as Colony Collapse Disorder
(CCD), “I wanted to find out whether native bees could fill in for them,”
she says. While Winfree cautions against extrapolating her results too
broadly to other crops in other parts of the country, “if we lost all
honeybees in this region to CCD tomorrow, between 88 and 90 percent of
the watermelon crop would be fine,” she says. “Native bees are providing
a backup planfor free.” <br><br>
Winfree’s results, published in <i>Ecology Letters</i>, have generated an
excited buzz among native pollinator proponents, a diverse group of
scientists, conservationists, gardening enthusiasts and others who are
sponsoring activities nationwide this June to celebrate the third
official National Pollinator Week. Yet even as they applaud her studyand
others that show wild bees contribute to the production of crops such as
blueberries, cranberries, peppers, tomatoes, alfalfa and squashthey
worry about the welfare of these unsung natives. <br><br>
<img src="http://www.nwf.org/nationalwildlife/images/062009/Pollinators_JJ09_01.jpg" width=534 height=350 alt="[]">
<br><br>
“There has been little effort to document the long-term status of
pollinator populations in the United States,” says biologist May
Berenbaum, chairman of the Department of Entomology at the University of
Illinois at Urbana-Champaign. Yet in a 2006 National Academy of Sciences
(NAS) report, a scientific committee chaired by Berenbaum found that in
cases where data do exist, pollinator population trends are “demonstrably
downward.” <br><br>
Pollinators comprise a diversity of wild creatures, from birds and bats
to butterflies, moths, beetles, flies and even the odd land mammal or
reptile. But “there’s no question that bees are the most important in
most ecosystems,” says Winfree, who calls the insects “the 800-pound
gorillas” of the pollinator world. Unlike social honeybees, imported to
North America in the 1600s, the majority of the continent’s native bees
are solitary, nesting in burrows on the ground or small holes in wood
rather than building hives. Worldwide, there are some 20,000 bee species,
4,000 of them found in North America. <br><br>
Bees and other pollinators are essential to human survival. “Without
them, you’d lose most of your plants, and ultimately everything else,”
says Winfree. To produce seeds and reproduce, three-quarters of the
world’s flowering plant species rely on animal pollinators. (The others
use the less precise methods of wind or water to transfer pollen between
male and female flower parts.) Animal-dependent plants include more than
two-thirds of the world’s crop species, whose fruits and seeds provide
more than 30 percent of the foods and beverages we consume. Scientists
estimate that in the United States alone, native bees perform up to $3
billion worth of pollination services annually. <br>
<img src="http://www.nwf.org/nationalwildlife/images/062009/Pollinators_JJ09_02.jpg" width=534 height=350 alt="[]">
<br><br>
Natural ecosystems and their inhabitants also rely on pollinators. Many
North American songbirds, for instance, feed on the fruits, seeds and
berries of plants pollinated by animals. Pollinating insects themselves,
especially their plump larvae, provide protein for adult songbirds and
their fast-growing fledglings. Even the notoriously carnivorous grizzly
bear depends more directly on pollinators than one might expect.
According to wildlife ecologist Kimberly Winter, NWF’s habitat programs
manager, in some places between 80 and 90 percent of the bear’s diet is
made up of fruits, nuts, bulbs and roots of animal-pollinated plants. On
an ecosystem level, “losing a pollinator can have a domino effect on
countless other species,” she says. <br><br>
To detect pollinator population trends, long-term surveys are essential.
“The few hardy souls who have undertaken such studies are finding
indisputable evidence of declines,” says Berenbaum. She cites the work of
biologist Arthur Shapiro, a professor of evolution and ecology at the
University of California–Davis who has been monitoring butterflies on
fixed transects across the state for the past 37 years. Many of the
several dozen species he has tracked have declined, some dramatically.
“Butterflies that were once considered utterly common are going into a
tailspin, and no one knows why,” says Shapiro. <br><br>
In addition to butterflies, the NAS report provides evidence of decline
in three other pollinator groups: hummingbirds, bats
andespeciallybumblebees. A 2008 report from the Xerces Society for
Invertebrate Conservation, a nonprofit based in Portland, Oregon, paints
an even bleaker picture of the familiar, fuzzy insects’ fate. Compiling
data from more than three dozen scientists and “citizen monitors” across
the country, the report concludes that populations of three formerly
common speciesthe rusty-patched, yellowbanded and western bumblebeehave
dropped drastically over the past decade. A fourth species, Franklin’s
bumblebee (restricted to coastal Oregon and Northern California), has
only been seen once in the past several years. <br><br>
Though the jury is still out on the cause of these declines, the most
likely culprit is an exotic disease introduced by commercially reared
bumblebees, says the society’s executive director, Scott Hoffman Black.
Between 1992 and 1994, he explains, queens of the western bumblebee, a
species commonly used to pollinate greenhouse tomatoes, were shipped to
Europe to produce colonies subsequently shipped back to U.S. farms.
Scientists suspect the bees picked up a fungal disease from European
bees, then spread it to wild bumblebees across the country as colonies
were moved among commercial growers. (All beleaguered species are closely
related to those that spent time in Europe.) “Like Native Americans
decimated by smallpox brought in by Europeans, our native bees have no
resistance to exotic diseases,” says Hoffman Black. <br><br>
Beyond diseasesuspected as a major cause of CCD in honeybeesblame for
pollinator declines runs the gamut: habitat loss and fragmentation,
introduced species, pesticides and global warming. “But in most cases, we
don’t know,” says Laurie Davies Adams, executive director of the
Pollinator Partnership, a San Francisco-based nonprofit working to raise
awareness about pollinators’ plight. “We simply haven’t paid enough
attention.” <br><br>
There are a handful of exceptions. In the U.S. Southwest, two species of
nectar-feeding batsthe lesser long-nosed and Mexican long-tongued
bathave declined due to destruction of their roosting caves. Pesticides
are implicated in problems facing several native insects, though given
the animals’ special sensitivity to these chemicals, “pathetically few
toxicity studies have been conducted, even on honeybees,” says Berenbaum.
<br><br>
<img src="http://www.nwf.org/nationalwildlife/images/062009/Pollinators_JJ09_03.jpg" width=534 height=350 alt="[]">
<br><br>
Like virtually all living things, pollinators are also threatened by
global warming. According to biologist David Inouye of the University of
Maryland, some are already beginning to respond to climate change. In the
Colorado Rockies, for example, he and his colleagues recently surveyed
the altitudinal distribution of several bumblebee species at the Rocky
Mountain Biological Laboratory (RMBL). They compared the results with
those of a survey they had conducted along the same transects as graduate
students more than 30 years agoand found that at least one species has
shifted its range upslope by 1,500 feet. <br><br>
Pollinators are particularly at risk to indirect effects of warmingwhen
changes in temperature or precipitation cause shifts in the distribution
of plants or the timing of nectar they produce. In another study at the
Colorado lab, Inouye and RMBL colleague Billy Barr found that springtime
emergence of Milbert’s tortoiseshell butterfly has been getting
progressively earlier since the 1970s. Yet blooming time of the region’s
spring wildflowers has not kept up. The findings demonstrate that
“pollinators and plants do not respond the same way to environmental
changes caused by global warming,” says Inouye. “This means they may lose
the synchrony they once had.” Inouye is particularly concerned about
hummingbirdsimportant wildflower pollinatorsthat migrate thousands of
miles between winter habitats in the Tropics and breeding grounds in
North America. Research shows that tropical and temperate ecosystems are
responding very differently to global warming, and there’s no way a
hummingbird wintering in Colombia would be able predict what the weather
is like in Colorado. <br><br>
<img src="http://www.nwf.org/nationalwildlife/images/062009/Pollinators_JJ09_04.jpg" width=267 height=345 alt="[]">
<br><br>
Fortunately, there’s good news as well. Thanks to the NAS report and
efforts of conservationists, there has been a flowering of appreciation
for native pollinators in recent years. Concern about European honeybees
has also helped. CCD, first detected soon after the report’s publication,
had “a silver lining,” says Hoffman Black. “Now many more people know
that their food is pollinated, and that we need bees and other animals to
do that.” <br><br>
Davies Adams agrees that “we see more interest in pollinators than just a
few years agoand more resources to help people help pollinators.” Among
her organization’s activities is the creation of a series of ecoregional
planting guides to advise gardeners on planting native species for
insects and other animals. Launched in 2008, the final set of 32 guides
is scheduled to be completed this June. The Xerces Society has published
the Pollinator Conservation Handbook as well as a series of guides for
farmers and managers of parks, golf courses and other lands. <br><br>
Perhaps the biggest coup scored by pollinator proponents came last year
with congressional reauthorization of the Farm Bill, which for the first
time has provided specific financial incentives to growers who restore
habitat for pollinators and authorized $100 million for research on the
animals. Winfree has applied for funding through the law to continue
working with USDA’s Natural Resources Conservation Service in New Jersey
on combinations of plants that attract the greatest diversity of
pollinators. She suspects the reason she found so many bees in her own
study is because the region’s small farms are nestled among suburban
gardens and scraps of native vegetation, habitats that provide nesting
sites and additional food for the insects. Similar research conducted
within vast monocultures of California’s Central Valley has so far been
less encouraging. <br><br>
Winfree, who launched her project in 2006, obtained equally promising
results during the 2007 and 2008 growing seasons. “When it comes to human
disturbances like fragmentation,” she says, “some bees may turn out to be
more robust than some larger animals like birds and mammals. And that
would be very good news for conservation.” <br><br>
<i>Senior Editor Laura Tangley provides food, water and nesting sites for
pollinators in her own yard.<br>
<font face="arial" size=2 color="#FFFFFF"><b>arden for Wildlife<br><br>
</i></font><font size=2>How to Plant for Pollinators<br><br>
</b>“The neat thing about pollinator conservation is that anyone, from
the owner of a golf course to an apartment dweller with a window box, can
do something to help,” says Scott Hoffman Black, executive director of
the Xerces Society for Invertebrate Conservation. All it takes is to
provide appropriate food and habitat for bees, butterflies and other
pollinating speciesand to avoid using the pesticides that harm them.
<br><br>
“Being pollinator-friendly also means you are being wildlife-friendly,”
says Kimberly Winter, NWF’s habitats program manager. “And you are
creating a sustainable ecosystem in your own backyard.” <br><br>
Here are a few suggestions to get started: <br><br>
To provide pollinators with the best sources of foodand to prevent the
spread of invasive specieschoose as many plants native to your region as
possible. For specific recommendations, consult the Pollinator
Partnership’s free ecoregional planting guide for your area
(<a href="http://www.pollinator.org">www.pollinator.org</a>); all you
need is a zip code. <br><br>
Select plants that provide a lot of nectar and pollen. Many ornamentals
have been specifically bred to produce little or none of these essential
foods. <br><br>
Plant a diversity of species so your yard will provide bees, butterflies
and other animals with nectar and pollen from spring through fall. To
attract bats and nocturnal moths, consider night-blooming plants in
addition to day-bloomers. <br><br>
Be a “messy” gardener: Leave some patches of unmulched soil and brush
piles that bees, birds and other animals can use to construct nests.
Consider building or purchasing a bee house for wood-nesting wasps and
bees. <br><br>
During hot, dry periods, provide water in shallow birdbaths or pools
where pollinators can easily alight. Some wasps and bees need mud to
build their nests, and butterflies like to gather in muddy puddles.
<br><br>
Do not use pesticides, and encourage your neighbors to reduce their
reliance on these chemicals. According to Winter, more pesticides are
used in urban areas today than in agricultural regions of the United
States. <br><br>
For more tips, check out these sites:
<a href="http://www.nwf.org/nationalwildlife//gardenforwildlife">
www.nwf.org</a> and <a href="http://www.xerces.org">www.xerces.org</a>.
<br>
</font><font face="arial" size=2 color="#FFFFFF"><b><i>riority<br><br>
</i></font><font size=2>Protecting Native Pollinators<br><br>
</b>Through its <i>Certified Wildlife Habitat</i>™ program, NWF
encourages the creation of habitat suitable for bees, birds, butterflies
and other pollinators, and educates landowners about appropriate host
plants as well as the risks of using pesticides. The program also offers
all the information needed to make your own yard welcoming to pollinators
and other native animals. Once you create this haven, you can have the
property certified as an official NWF wildlife habitat. To learn more, go
to
<a href="http://www.nwf.org/nationalwildlife//gardenforwildlife">
www.nwf.org/gardenforwildlife</a>.<br>
</font><font face="arial" size=2 color="#FFFFFF"><b><i>
<a name="challenge"></a>b Exclusive<br><br>
</i></font><font size=2>Photo Challenge: Plants and Pollinators<br><br>
</b>
<img src="http://www.nwf.org/nationalwildlife/images/062009/black_swallowtail.jpg" width=180 height=134 alt="[]">
</b>To celebrate National Pollinator Week (June 22–28), <i>National
Wildlife</i> is hosting a “Plants and Pollinators” photo challenge
competition on Flickr. We’re looking for images of bees, butterflies,
hummingbirds and other animal pollinators, as well as the plants that
depend on them for survival. If you’ve got photos fitting this
description, upload them to the
<a href="http://www.flickr.com/groups/nwmag?&s_src=Flickr_Photo_Challenge&s_subsrc=June_July_2009_NW_online">
<i>National
Wildlife</a></i>
<a href="http://www.flickr.com/groups/nwmag?&s_src=Flickr_Photo_Challenge&s_subsrc=June_July_2009_NW_online">
Magazine Photo Group</a> by June 28 (with the tag
"Pollinator-NW09") for your chance to win. In July, we will
select finalists among these images and ask Flickr members and others to
vote for their favorite. The top vote-getter will receive an official NWF
wildlife field guide and, if not already a member, a one-year membership
to the National Wildlife Federation. This membership includes a free
subscription to <i>National Wildlife</i> magazine.<br><br>
For more details about the photo challenge, visit the
<a href="http://www.flickr.com/groups/nwmag?&s_src=Flickr_Photo_Challenge&s_subsrc=June_July_2009_NW_online">
<i>National
Wildlife</a></i>
<a href="http://www.flickr.com/groups/nwmag?&s_src=Flickr_Photo_Challenge&s_subsrc=June_July_2009_NW_online">
Magazine Photo Group</a> page on Flickr. <br><br>
</font>Please help us to protect our natural resources, reuse or recycle
this paper when you are done.<br><br>
© 2009 National Wildlife Federation, All rights reserved. - Read more
great stories online at
<a href="http://www.nwf.org/nationalwildlife" eudora="autourl">
www.nwf.org/nationalwildlife<br><br>
<br>
</a><x-sigsep><p></x-sigsep>
*************************<br>
Scott Hoffman Black<br>
Ecologist/Entomologist<br>
Executive Director<br>
The Xerces Society for Invertebrate Conservation<br>
4828 SE Hawthorne <br>
Portland, OR 97215 <br>
Direct line (503) 449-3792<br>
sblack@xerces.org<br><br>
<i>The Xerces Society is an international, nonprofit organization that
protects wildlife through the conservation of invertebrates and their
habitat. <br>
</i> <br>
To join the Society, make a contribution, or read about our work, <br>
please visit
<a href="http://www.xerces.org/">www.xerces.org</a>.<br><br>
<br>
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