Pollinators
Written by Rhonda KranzRevised June 2011
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PollinatorsWritten by Rhonda KranzRevised June 2011 |
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Pollinators come in all shapes and sizes. More than 200,000 invertebrates and 2,000 vertebrates serve as pollinators worldwide including insects, birds, mammals, and even reptiles. The co-evolution of these pollinators and their host plants is one of nature's unique solutions to the dilemma of sexual reproduction.
Test your knowledge about pollinators with our Pollination Quiz
Pollination is central to successful reproduction in most plants. It is the transfer of pollen grains from the anthers of one flower to the stigmas of the same or another flower. Movement of pollen via wind is a common strategy and in our region we helplessly encounter this each spring as large quantities of oak and pine pollen move through the air in the hopes that some of it will land on flowers of the same species. Although rare, water can act as a medium for pollination. But worldwide, more than 70% of flowering plants rely on animals to transport pollen for them.
The relationships between flowering plants and their pollinators have been evolving since the early Cretaceous (140 million years ago). These are mutually beneficial relationships in which the animal gains food and nutrients, and the plant is assisted in reproduction. The plants produce nectar, a nutritious sugar-based substance that attracts the pollinator, and the pollen is picked up in the process of collecting the nectar. There are species that cheat of course, and have become adept at "nectar robbing," by taking nectar without passing the anthers of the flower where pollen is located. It's fun to watch a mixed group of bee species on flower garden plants such as Hasta to see which of them enter through the mouth of the flower and which ones make but a brief stop at the base of the flower, where a tiny hole divulges their more direct route to the nectar.
Flowers use color, shape, odor, and timing to appeal to pollinators. "Pollinator Syndromes" describe flower characteristics, or traits, that may appeal to a particular type of pollinator. Plants such as the Maryland state flower, the Black Eyed Susan, provide easy access to nectar and attract a variety of pollinators. Others such as the Trumpet Vine have evolved to minimize the amount of pollen wasted by random visits of pollinators to other flower species. With its bright red flowers and deep tubular blossoms it specializes in attracting hummingbirds which can reach the nectar with their long straight bill. If you encounter Skunk Cabbage in bloom in early spring along local creeks you may be put off by the skunk-like odor, but it is a siren call to beetles and flies.
Pollinators come in all shapes and sizes. At least 200,000 invertebrate species act as pollinators including bees, butterflies, moths, flies, beetles, and yes, even mosquitoes. (While the female mosquito is extracting blood to produce eggs, the males are extracting nectar.) There are an estimated 2,000 species of vertebrate pollinators. Hummingbirds and bats of course, but also surprises like doves, opossums, and lizards.
Pollinators provide indispensable ecological and economic benefits. Several species do both. The Mexican long nose bats pollinate both the saguaro cactus, which provides homes and food for a multitude of desert species, and the Agave, which supplies us with tequila for our margaritas. Globally, pollinators are important for the production of roughly 30 percent of the human diet, edible oils, fibers such as cotton and flax, alcoholic beverages, and medicines created from plants. In the US more than 150 food crops like almonds, apples, blueberries, tomatoes, and squash rely on pollinators. A lot of our favorite imports - like chocolate and coffee - too.
Insects are the dominate pollinators world wide, and bees are considered the most important. There are over 4000 species of bees in the US, and with a few exceptions they are wild bees native to the US. But despite this, when people hear "bee" most think of the honeybee. Honeybees were brought here from Europe in the seventeenth century as a crop pollinator and they have become the single most economically important pollinator in the US. Several estimates of the yearly agricultural services provided by pollinators exceed $15 billion. Pollination services provided by wild bees are also important and have been estimated at $3 billion per year.
In 2006, the National Research Council put out a report, Status of Pollinators in North America, which documents a serious decline in native pollinators. The report identifies the main causes as habitat loss, pesticide use, and diseases. Habitat destruction is caused by changes in land use. When people convert wild lands for domestic uses the food and nesting requirements of many pollinators are disrupted. Pesticides are a major threat to insect pollinators, although precautions such as better regulation, avoidance of overspray, and changes in the type and timing of pesticide use can reduce the threat.
The US Fish and Wildlife Service lists over 50 pollinator species as threatened or endangered. Continued declines in pollinator activity could mean rising costs for pollinator-dependent fruits and vegetables and the disruption of entire ecological systems.
There are some encouraging responses such as the creation of new habitats in some unlikely places: the US Golf Association's Wildlinks Program is creating wildlife habitat along golf courses; the Farm Bill provides incentives for farmers to build permanent vegetative buffers next to agricultural fields; and PEPCO has been preserving open sunny pollinator friendly habitats along its transmission line corridors such as east of New Hampshire Avenue in lower Sligo Creek Park.
Questions and Answers: Colony Collapse Disorder
USDA 2010 Honey Bee Colony Collapse Disorder Progress Report
PBS Nature "Silence of the Bees"
Honey Bee Disappearance (CCD) and What You Can Do
Checklist of Butterflies of Sligo Creek
Butterflies and Moths of North America
Flora of the Washington-Baltimore area
University of Maryland, Department of Plant Biology - James Reveal's page
The Flora Project, native plants of Alexandria, VA
What You Can Do To Protect Pollinators Fact Sheet
One of the easiest (and most rewarding) ways to provide suitable habitat for pollinators is to plant a wide variety of locally native flowering plants in your garden. Beyond your own backyard, you'll find many other places where pollinator habitats can be restored or protected. Through community or school gardening programs, you can encourage the planting of native flowers in local spaces such as parks, playgrounds, roadways, golf courses, and around public buildings. Vegetable gardens are another great way to provide food for both you and native pollinators.
Pollinator Partnership, Pollinator Gardening resources
Fish and Wildlife Service Plant a Pollinator Garden
US Forest Service, Gardening for Pollinators
Pollinators are Garden Essentials
All Vegetables Require Pollination, But Not All Achieve it the Same Way
Botanical Garden, the Butterfly Garden
Gardening Tips from the Smithsonian Butterfly Garden - Video
Pollinator Friendly Planting Guides, NAPPC
National Wildlife Federation's Backyard Habitat Program
Xerces Society for Invertebrate Conservation Resources "Attracting Native Pollinators"
National Arboretum Gardening Page
Each year the final week of June is celebrated as "National Pollinator Week" with a variety of events across the US. In September 2006 the US Senate signed Resolution 580 designating National Pollinator Week to recognize "the importance of pollinators to ecosystem health and agriculture in the United States". The Secretary of Agriculture followed with a proclamation "calling on the people of the United States to join in celebrating the vital significance of pollinators". www.fws.gov/pollinators/pdfs/pollinatorweekres580.pdf
June 21 (Tuesday) - Beltsville Bee Research Lab - Open House 10:00 a.m. - 3:30 p.m.
The BRL will host an open house for the public to highlight honey bee research activities conducted at the nation's capital by the USDA Agriculture Research Service. Visit the lab and hear about our research, advanced beekeeping techniques, and how to identify bee diseases.
www.ars.usda.gov/sp2UserFiles/Place/12750500/brl-pdf/OpenHouseSchedule2011.pdf
June 21 (Tuesday) - Maryland Pollinator Conservation Planning Short Course
The content of this course is tailored to the needs of NRCS conservation planners, Soil and Water Conservation Districts, Cooperative Extension, state agencies, crop consultants, farmers, land managers, and master gardeners. Beltsville, MD
events.r20.constantcontact.com/register/event?llr=tnjebhdab&oeidk=a07e3ld3g5zb8f79c5d
June 25, 2011 - Rockwood Honey Bee Festival - noon - 5:00 p.m.
There will BEE something for everyone of every age; music, face painting, arts and crafts, bee items for sale such as beeswax candles and local honey, refreshments, games, nature activities and more. There will be informative programs about backyard beekeeping, gardening for bees, current apiculture news and more. Plus view our live honeybee observation hive. Sponsored by the Rockwood Park Backyard Beekeepers Association. Details: 804-674-1629 or email mrbeeva@yahoo.com. Rockwood Nature Center, 3401Courthouse Road, North Chesterfield, VA,
www.chesterfieldoutdoorprograms.com/rockwood.html
Pollination in Poetry and Prose
Pollinator Conservation Factsheets
Pollinator Partnership education resources
Ecological Society of America Communicating Ecosystem Services Project, Pollination Toolkit
Natural Resources Conservation Service's Backyard Conservation Program
National Wildlife Federation's Backyard Habitat Program
The Inouye Database: An Interactive Bibliography of Pollination Publications, NBII
Wings of Fancy, Live Butterfly Exhibit at Brookside Gardens, May - September
Pollinator Live, a Distance Learning Adventure
DC Area Butterfly Garden Beginning to Grow
North American Butterfly Association
Butterflies and Moths of North America
Monarch Watch (University of Kansas Entomology Program)
Celebrating Wildflowers, Bumblebees by David Inouye
Bat Conservation International Photo Library
North American Pollinator Protection Campaign
The Xerces Society for Invertebrate Conservation
Pollinator Conservation Consortium - Arizona-Sonora Desert Museum
Bat Conservation International
Fish and Wildlife, Pollinators
In 2007 the Post Office released a Pollinator Commemorative Stamp, an intricate ecological masterpiece of bee, butterfly, hummingbird and bat busily at work in full-color flowers.
www.fws.gov/home/feature/2006/USPS_pollinator_stamp.pdf
Takoma Park Crosses Finish Line in Race to Become First MD Community Wildlife Habitat
www.fosc.org/WildlifeHabitat.htm
Pollinator Nature Walk in Sligo - June 30, 2007
www.fosc.org/PollinatorWalkJun2007.htm