Pollinators Under Seige
Surfing the Net one morning, I came across an intriguing conversation. I was trying to find some new plants for my butterfly garden, when I encountered "Honeybees, where are you?", a web site inviting answers to the question, "Have you seen any honeybees in your yard this year?". As I eavesdropped through the entries, I was amazed how few honeybees had been sighted in backyard's across the country. "..west Thennessee...lots of bumble bees but few honeybees. My clover covered hill is pretty quiet too." "I've not seen any honeybees the last two years. Lots and lots of bumblebees, many butterflies too, no honeybees." My curiosity peaked and I decided to delve deeper for information.
Apis mellifera, our common honeybee, arrived here with the pilgrims over 375 years ago. Since that fateful day, it is impossible to find any place in the world that is free of managed or feral bees. Honeybees are the cattle of the pollination world and the agricultural industry relies heavily on them. They can be easily managed in large hives while most other bees are ground nesting or solitary; the hives can be rented out at the right time and trucked to the desired location to help pollinate the crops; and they produce the added benefit of excess honey. A strong hive yields about 88 pounds of surplus collectible honey. In contrast, the equivalent amount of honey takes 102 colonies of bumblebees (which are choosey in their nest-sites and prefer hollows) or about 200-400 carpenter bees scattered over many square miles of desert.
But our beloved honeybee is in trouble, grave trouble as the web-site conversation indicates. Two mites, the tracheal and varroa (possibly carried here by Africanized bees), along with pesticides, and fungal, bacterial and viral diseases, have reduced our feral bee population by 90 percent while 50 percent of our managed hives have been hit. In fact, if you examine managed honeybee colonies in the United States over the last 75 years, the numbers peaked in 1947 at 5.9 million. Since then, with the increased post-war use of organochlorine pesticides, these numbers have declined to only 2.6 million managed hives in 1995. With the European honeybee hit hard from all these different directions, I wondered what that meant for our farmers, as well as our eco-systems in general. Were there other pollinators that could take up the slack for the honeybee?
By beginning this seemingly innocent computer search, I had stumbled into an ecological house of mirrors, an unending complexity of plant/pollinator relationships. I was soon to discover these fragile relationships are unraveling, beseiged by habitat destruction, pesticides, and other modern-day factors. The price we pay sits right before us at our dinner table.
Although the pieces of this gigantic puzzle are not all in place, scientists around the world are coming to the alarming conclusion that our animal pollinators are in trouble, and this in turn has major consequences for the world's flowering plants--plants we depend upon and take for granted in our everyday diet. As the story unfolds, even botanists are amazed, for what they once took to be a small piece of natural history--pollination--they're now realizing has ecosystem-wide consequences. An endangered plant or its pollinator can cause whole eco-systems to crumble--what biologists refer to as "cascading extinctions". To begin to understand one of our least understood stories in biology, we must start with the basics.
Every school child learns about the basics of pollination. Essentially the job of the flower is to produce the sexual parts for reproductory purposes. Anthers produce pollen. These are the male parts of the flower. Somehow this pollen must be transferred to the female parts, the stigma, in order to begin the process of pollination, and fertilization, which produces the fruit and seeds. This process of transferring pollen from one plant to another can be done in essentially two ways: through wind pollination or through an animal delivering the pollen package.
Wind pollination is chancy at best. In order for it to be effective, plants must produce massive amounts of gametes. That is why we often see pines raining yellow clouds. It is pure luck where the pollen falls. Only some of it will hit its mark, and the key is for these plants to grow in large stands. Grasses such as bamboos, and conifers, like firs and pines, still use this primitive method.
As evolution progressed, another method, much more effective, unfolded. Early plants are thought to have evolved alongside insects, making their relationships fantastically intertwined. These early flowering plants took advantage of the mobile abilities of insects and their regular feeding routes. By evolving specific rewards for insects, the insects in return delivered the plant's pollen package door-to-door over long distances.
In this way a forest, or a desert, can contain much greater bio-diversity, since many different kinds of animal-pollinated plant species can co-exist. As a testimony to this, today's modern tropical lowland forests contain less than 3% of plants which rely on wind pollination. Animal-pollinated plants are the clear winners in the most bio-diverse habitats.
The earliest flowers looked a lot like Magnolias, with large broad leaf-like stamens that attracted beetles. These plants produced no nectar, but provided bright yellow, oily, pollen grains containing white protein-rich 'food bodies'. In addition, the beetles could take shelter in these large flowers, as well as procreate. The rich food drew the beetles away from devouring the tender parts of the plant, and some of the pollen stayed on their hard bodies as they moved from one plant to the next. Because beetles like to defecate and copulate a lot while moving the pollen around as well, biologists coined the technical term "mess and soil pollination".
As early insects were more regularly rewarded with nutritious treats for dispersing pollen, some began to specialize by seeking particular kinds of blossoms, which led to greater diversity of flower shapes, sizes, and blooming times. By the end of the late Cretaceous Period (100 million years ago), at least 22,000 plant species had developed and bees had diverged into their modern families. Coevolution of plants and hummingbirds came later (about 65 million years ago) with vertebrate pollinators such as bats being, of course, the last to develop.
Although some plants can self-pollinate, most prefer to cross-pollinate,which produces greater seed set and less in-breeding, and therefore is a much wiser survival technique. Plants even go so far as to prevent self-pollination. Stamens and carpels of a single flower might mature at different times, or these organs may be specifically arranged within the flower so that self-pollination is unlikely. Still, especially on islands where pollinators may be scarce, there exist plants with the ability to self-pollinate. But be forewarned, this ability is an evolutionary strategy which develops over evolutionary time, not human time.
Early on flowers began to develop specific strategies for luring insects. Flower depth and shape evolved to suit their host(s). A marvelous example is orchids. Orchids have a little package of pollen which appears like a miniature egg yolk wrapped in a leathery brown and sticky sac. Each orchid genus has specific body locations on its visiting bee to which it glues this sac. Until that bee finds the correct and corresponding orchid which will dislodge this package, he can go for days with the pollinia stuck between his eyes, or on his abdomen, or where ever the exact mapped location is for that orchid genus. When the correct flower mate is found, it's shape forces the bee to twist and turn, thus dislodging the pollen package and pollinating the flower.
In return for their labor, orchids provide these special bees, called euglossine bees, with unique scents. The bees scape the fragrances up from the flowers and somehow process them biochemically in glands in their hindlegs, transforming them into aerosal aphrodisiacs which make the males irresistible to the females. So the flower in turn acts in the bees survival as the bee acts in the flowers interests.
Flower shape plays an important part in the rampant success of our non-native, the Scotch Broom (Cytisus scoparius). It's need for a weightier pollinator invites our native bumblebees to fill this niche. In a young flower which is not yet open, the keel and wings form one unit, the keel "hooked in" by a tooth on each side. Like a lock waiting for the exact key, the right pollinator will spring the mechanism, like a mousetrap, popping the stamens out to powder the visitor's belly and back with pollen. Only the heavier bees, the carpenter and bumblebee, are weighty enough to trigger this mechanism. Going from flower to flower, they trigger explosions all over the place, with the air full of pollen. Honeybees, on the other hand, being much lighter, have to work very hard to get anywhere and tend to steal the nectar without tripping the mechanism.
Colors became fine-tuned to the color-spectrum seen by the potential animal pollinator. Flowers pollinated by bees often have invisible nectar guides, markings that help direct the bee as it taxies to the nectaries. These markings are in ultraviolet. Bee's eyesight reflects a shift toward the ultraviolet, in others words, they cannot see our reds, but can see ultraviolet rays as well as yellows and blues. Red is a color usually reserved for bird pollinators. Night pollinators such as moths and bats are attracted to white flowers as white shows up more brilliantly at night.
Even smell has specific appeals. Carrion and dung flies are lured to plants smelling like rotting flesh; bird pollinated flowers have no odor since birds can't smell; beetle pollinated flowers have a strong, fruity smell.
Then there are variations on these themes. The moths that pollinate desert Yuccas have an elaborate symbiosis. Female moths will gather and carry pollen around most of their adult lives. When the time comes to reproduce, the female cuts into the yucca flower ovary, deposits her eggs, and stows a small amount of the pollen she has saved. As the larva hatches, it eats only a small portion of the developing seeds, leaving many intact. Interesting enough, the yucca plant tends to shed flowers with high levels of eggs in them, especially if they've been visited only a few times by the moths. In this way the plant naturally selects for moths that produce just enough eggs to get by and will pollinate dependably and repeatedly.
Around the turn of the century, a botanist named Paul Knuth began to categorize these characteristics. By 1954, Stefan Vogel, a famous German biologist, coined the term 'pollinator syndrome' and further refined all the known information. Organized charts with flower traits, such as color or flower shape, were matched to their pollination 'vector' or animal method of transport. The pollinator syndrome method persisted until the early '70's, when botanists began to uncover increasingly complex information and relationships that defied the simplistics of the charts. Plants visited by hummingbirds did not always conform to a 'bird pollination syndrome'. Plants don't always time their flowers to open with the migration of their seeming pollinator. Plant/pollinator syndromes was simply too easy an explanation and underestimated nature's complex relationships.
A new understanding, called plant/pollinator landscapes, began to emerge among botanists in the 1970's. This new concept was based on a more thorough observation of an entire eco-system---it's plants, pollinators, and flowering times. The concept of plant/pollinator landscapes assumes there are key traits of flowering plants and pollinators that cluster together in time and space, instead of varying independently between species or genuses of plants, as with the pollinator syndromes theory. Traits could vary within a species as well as between species. For instance, our native spice bush (Calycanthus occidentalis) which is beetle pollinated, flowers in one landscape at a different time than in another landscape cluster, and might attract a different beetle. Likewise, some beetles may actively pollinate spicebushes while some prefer to visit other neighboring plants. This kind of categorizing requires observing entire ecological interactions.
This new way of viewing plant/pollinator relationships is critical, because it allows us to view whole systems, rather than single plant species, and reveals the dependencies of one species upon others within that system. Scientists agree that information on pollinator interactions with plants is often the weakest link in our chain of understanding of how ecosystems function. Viewing plants within plant/pollinator landscapes allows us to see how the decline of one species, either the plant or the pollinator, could cause other animal or plant species to decline. This understanding is the beginning of working out methods to protect whole eco-systems, rather than isolated parts of the whole. Judith Bronstein has developed five different types of plant/pollinator landscapes revolving around pollen and nectar availability, ranging from generalist migrator landscapes to specialist pollinators visiting plants with prolonged bloom times in environments without seasons, such as tropical figs and their wasp pollinators.
When we talk about plant/pollinator landscapes, we focus in on ecological systems. And if these systems are disturbed--fragmented-- we find species in danger of extinction. Referred to as the 'extinction debt', a debt that will come due in future generations, it has now been verified that even a slight increase in habitat fragmentation threatens many species, particularly in places where a large portion of a habitat has already been fragmented. Beverly Rathcke and Eric Jules of the University of Michigan echo these concerns when they say "Habitat fragmentation is often considered to be one of the greatest threats to terrestrial biodiversity ....All available evidence shows that pollinator abundance and diversity decline with fragmentation".
For a graphic example of natural habitat fragmentation, one need only look at islands. In the South Pacific, 'fragmented' islands depend on a keystone pollinator. A keystone species is a species that is so essential to the landscape, that if removed or reduced, causes a domino effect of extinctions to occur. Flying foxes fill this niche among these islands. They are the only animal available to move pollen from one tree to the next, or from one island to the next. But when a naturally fragmented, and therefore fragile, system is disturbed, decline occurs at a rapid rate, and this is exactly what is occurring. Flying floxes are in serious decline throughout the world, including the South Pacific and Australia. In the Philippines alone in the 1920's, over 150,000 used to congregate in areas. Now there are seldom more than a couple hundred seen together at any one time. Three species are already extinct in the Pacific Islands. The loss of flying foxes, or bats, will have serious consequeces for the long-term viability of isolated island ecosystems.
Islands are no longer the most isolated systems. Our large land masses are being carved up into island-like patches, with keystone pollinators removed from their nectar sources. Take Good's Banksia in Western Australia, where farming and roadside development have cut the countryside up into semi-arid fragmented habitats. This banksia is one of the extinction debts that will come due in our lifetime. B.B. LaMont, an expert on Australia's disappearing banksias, states there are only 16 remaining small populations, with 9 of the 16 averaging only eight plants per patch. The larger populations average 150 plants, but these are isolated within farmlands or nature preserves. Among the large populations, seed production is declining, with decreased cone production and also cones not being fully fertilized. This seems to be due to either poor soils or increased competition within the patches.
In the smaller patches, even though the plants are relatively the same size as the larger patches, five of the nine had no fertile cones for over a decade, with the remaining sections producing extremely low seed set. The prominent pollinators, the nocturnal honey possum and the honeyeater, have not been sighted among the seedless plants, even though the roads nearby have limited traffic in the evening when they are most active. The roadside populations are simply too small to attact their pollinators.
From his extensive work, La Mont concludes that "the sobering message...is that a series of small populations may not have the same conservation value as a larger one with the same total population size...[There] may be a threshold below which local extinction is inevitable."
The Evening Primrose (Oenothera deltoides subspecies howellii) is a victim of modern-day encroachment, like an island being eroded away by the industrial seas.
The Antioch Dunes evening primrose is a rare subspecies found within a natural dune field where the Sacramento River meets the San Joaquin in California. Once over 200 acres, the dunes have been reduced to less than 30, with the rare flower growing in only 12 of those acres. It was the first "critical habitat" designation along with the plants' stature of endangered species. For more than a century Antioch Dunes has been beset by a variety of man-made problems: exotic grasses threatening to choke out natives, a wallboard factory smothering the area with gypsum dust, tourists and recreational visitors trampling the dunes, and insecticide spray on adjacent vineyards.
Oenothera deltoides is an obligate outcrosser--that is, it must transfer pollen between plants to reproduce. The term pollinator limitation is a key term used by biologists to mean a plant is not receiving enough visits from pollen-carrying animals frequently enough to ensure high seed set per fruit. Some types of flowers may require only one or two visits for good seed set, while other kinds of plants require multiple visits. If a plant is inadequately pollinated, it will either not set fruit or it's fruit will be misshapen with low seed production.
The main pollinator of this primrose is the hawkmoth, which flies by night. Botanist Bruce Pavlik has studied Antioch Dunes for years. "We stayed out night after night, hoping to catch a hawkmoth, and never noticed a single one of them." Hawkmoths have been scarce to the dunes for over 35 years, probably due to the heavy pesticide use on the vineyards. Although the vineyards have been abandoned for years, the moths have not reemerged. In 1987, 20% of Oenothera ovules developed into ripe seed. This is a third of the normal seed set. Pavlik estimates that pollinator limitation was responsible for over 65% of the total ovules failing to produce mature seeds. Pavlik guesses that bumblebees, which although not prevalent at the dunes, have been sighted with large amounts of pollen on their abdomen, are responsible for the seed set that is occurring.
Genetic drift is occuring at the Dunes. Genetic drift takes place in small isolated populations of plants and animals and refers to the loss of genetic traits from a species. In a large population of living organisms, any specific trait is likely to be carried by at least a few individuals, and will continue unless it is biologically undesireable. Genetic drift leads to loss of survival traits in a species. Fewer potential mates among any small plant population leads to inbreeding, which increases genetic erosion, produces lower seed set and lower seed germination rates. Smaller plant populations attract fewer pollinators, who now abandon the site. Recalling plant/pollinator landscapes, other plant species that these pollinators serviced may decline as well. Rathcke and Jules state clearly that "the pollination success of one plant species can also be influenced directly by the presence of other plant species that maintain pollinators. The disruption of such sequential mutualisms could cause cascading extinctions through the community".
Like the flying fox, an animal pollinator, a plant can also be a keystone mutualist in a landscape. In tropical forests, figs hold the eco-fabric together. Seventy percent of the vertebrates of these forests depend on figs for their diets. There are over 750 different fig species in the world and the majority rely on different species of tiny wasps as their exclusive pollinator. The figs need the trees of the tropical forests to establish themselves, and the wasps to propagate them. Through either logging and clear-cutting, or pesticides which wipe out the wasps, a decline in the fig population affects all the animals that feed upon these figs. A series of cascading extinctions would then be eminent. As Judith Bronstein points out, "monkeys would radically shift their diets or starve. With fewer animals feeding on fig fruits and seeds, perhaps there would be reduced food for predators such as raptors and jaguars. This isn't a trivial example but a very real threat due to tropical deforestation. " When we shift our gaze from pollinator vectors to whole eco-systems, the wider, dynamic view comes into focus. In this case, if the keystone species falls, then the bridge it holds together comes crumbling down.
Another type of plant/pollinator landscape that has been greatly disturbed by habitat loss is the migrating pollinators. Monarch butterflies are locally endangered, even though the species is not globally endangered at this time. The phenomenon of the migratory habits of the monarchs is well-known. There are only a few sites which the monarchs have chosen to over-winter at in Mexico and California. Interestingly enough, it has been proposed that Monarchs only began these migratory patterns after Europeans arrived and so dramatically. altered the landscape. Deforestation led to fewer overwintering sites, while the opening of forests into meadows resulted in the proliferation of milkweeds, a plant the larvae and adults rely on. The theory goes that the monarchs actually expanded their range while narrowing their overwintering sites to a few chosen spots.
Monarchs are very specific about their overwintering needs, and choose sites which have suitable forest canopy cover, specific climactic buffers, winter nectar sources, and enough standing water. Many of these sites have been irrevocably altered or destroyed. In California alone, more than 21 sites have been destroyed, with 7 of the remaining 15 sites dramatically altered by land developers over the last twenty years. In Mexico, the monarchs cluster on the slopes of Sierra El Campanario, Michocan, over 8,700 feet high, in the oyamel firs, or "sacred firs" as the locals refer to them. The monarchs arrive from their 2,000 mile journey, exhausted, with little fat reserves left. Up to 20,000 die per acre over the winter due to exhaustion, hunger, or cold. There are over 30 million monarches situated within 12 acres. Because these forests have been logged, or cleared for farming and grazing, the monarchs have been squeezed into a tighter and tighter space, with 10 sites left, only 5 of which are protected sanctuaries. With monarchs confined into small spaces of historically high concentrations, any shift in the landscape--an extreme climactic fluctuation; logging; loss of trees due to natural causes such as bark beetles or disease--will spell certain death for unusually high numbers of butterflies.
If those risks weren't enough, the monarchs must contend with habitat loss along their migratory corrider, for they depend on flowers to be providing nectar and host plants to lay their eggs while they pass through areas. Empty lots full of weeds, including milkweeds for monarch larvae to feed on, have been bulldozed into homes and shopping malls. In addition to habitat destruction, migrants face the dangers of pesticide sprays along their routes. The spraying of paraquat on marijuana fields alone in Mexico has eliminated butterflies from entire valleys.
Land development, farming, logging, and industrialization aren't the only factors creating habitat fragmentation. As mentioned before, pesticides and herbicides play are huge role. In some of the most biologically diverse countries in the world such as Ecuador, Brazil, Malaysia, and Mexico, pesticide use is unregulated and on the increase. Chemicals are used by people with no knowledge of safety issues. With the opening of trade between the United States and Mexico, (NAFTA), importation of pesticides has increased. Chemicals that are banned in the United States are legal for export to other countries. 471 species of butterflies are found in Mexico while only 292 are known in the United States, and yet 12 of the chemicals currently in use in Northern Mexico causes damage to the endrocrine systems of animals, as well as pollinators.
Brazil is the major user and producer of pesticides in Latin America. The country is among the world's most diverse in species, as well as boasts 3rd in endemic (found only in that country) plants and animals. Deforestation is followed by agricultural pesticide use to control weeds, cotton pests, and mosquitos at the rate of 5 pounds per year for each of the 23 million and growing farmworkers.
Although DDT has been banned in the United States and Canada and replacement chemicals may be safer for birds, some have proved deadly for pollinators. "They're not a magic bullet aimed at just one organism. They're quite toxic to a broad sweep of organisms, including bees and butterflies", says Stephen Buchmann, coauthor of The Forgotton Pollinators. "Not all insecticides are created equal. DDT is moderately poisonous to honeybees and for solitary bees, while highly toxic killers include such formulations as malathion."
A good illustration of our own pesticide decimation of pollinators is the alkali bee. Alfalfa flowers are very similar to scotch broom flowers with the keel and wing petals needing to be "unhinged". We saw that honeybees rarely trip this mechanism, but alkali bees are masters at this. In the 1940's in the Great Basin area of Utah, farmers realized that alkali bees, not honeybees, were responsible for pollinating more than 50% of alfalfa flowers found in their fields. The reason Utah was the principle producer of alfalfa seeds in the 20's and 30's was because of alkali bees, whose nesting sites at that time ran into the millions. Once farmers discovered the secrets of their high productivity, they began managing these bees. Since the alkali bee is a ground-nester, they formed troughs along the edge of their fields and lined them with special materials to provide suitable sites for alkali bee burrows. With that care and attention, alkali bees became the first ground-nesting bee to be managed.
But troubles began in the late 1940's, when the increased demand for seed caused the farmers to plough new sites, inviting hugh flocks of gulls to eat overwintering bee larvae. Then with increasing pesticide use in the 50's and 60's, the alkali bee numbers dwindled. Today their numbers are nothing compared to what they once were.
Pesticides aren't the only problem here. The alkali bee story illustrates as well what happens when adjacent wild lands are cleared for greater crop production. Most bees are either solitary, or ground-nesting, or both. When native vegetation is cleared and nothing but cultivated, managed fields remain, there are no nesting sites or nesting materials for these bees.
Blueberries have tiny vase-shaped flowers which are simply too deep for the honeybee's tongue. Thus they are ineffective pollinators. When the southeastern blueberry bee does it's work, blueberry production soars . The long tongue of the southeastern blueberry bee is finely equipped for this job. Honeybees are simply ineffective at this work. Still, hungry for profits, farmers have enlarged their fields by clearing and planting neighboring wildlands, destroying the homes of the very bee that services them most effectively.
All this land clearing and destruction of wild forages actually explains why our European honeybee has been so successful. Honeybees, like their African cousins, love to follow humans around. They are a disturbance-loving bee. As tropical rainforests are cleared, Africanized bees are the first bees to colonize the slash-and-burn areas, competing with the now displaced natives.
Honeybees also have competed and displaced our native bees for over 300 years. It is impossible to know what the North American native plant/pollinator landscapes looked like, as its' been so altered by the European honeybee. Little Apis mellifera accomplishes this not by aggression, but through simply overwhelming natives with the sheer force of their numbers, as well as foraging in the early morning hours when temperatures are lower and nectar production may be at its apex in many plants. Bumblebees, in contrast, are large and slow-moving, barely sipping fast enough to feed themselves, let alone their brood.
Each year, growers rent over a million honeybee colonies which pollinate $10 billion worth of crops. More than 100 crops in the United States are pollinated by winged insects with honeybees leading the pack. As honeybees displace our natives, and mites, pesticides, and other factors decimate our honeybees, who will pollinate our crops? These eminent threats to the honeybee population, even if reversible, reveal the wisdom in managing and preserving our native pollinators.
Of the 800 species of plants that are cultivated world-wide for human food, at least 150 rely to some extent on wild pollinators. Only 15% of these crops are pollinated by honeybees. For the United States, out of 60 crops critical to our economy, seven currently worth $1.25 billion a year are pollinated primarily by wild insects. These include cashews, squash, mangos, cardamon, cacao (chocolate), cranberries and highbush blueberries. Natives can fill the niche left by honeybee losses. According to Stephen Buchmann, if no native pollinators replaced the honeybees lost for over 60 crops in the United States, our annual losses would be up to $5.7 billion a year. With alternative pollinators included in these figures, these projected losses amount to $1.6 billion.
Preserving our natives obviously takes some forethought. Maintaining wild fields adjacent to and interspersed within our croplands, moving toward more integrated pest management with less emphasis on pesticides, and a global policy on pesticides are all first steps. Sara Stein, author of Noah's Garden, advocates a 'mosaic ecosystem suburbia', planned communities of adjacent lots connected by hedgerows, thickets, and dotted with flowering meadows, giving our wildlife feeding corridors in which to graze.
There are some good signs. By restoring 2 1/2 new acres at Antioch Dunes with trucked-in sand and newly planted buckwheats, the metalmark butterfly population has responded dramatically. Biologists are cautious though, and remind us that eco-systems cannot be moved around like rugs. There is still alot to understand about the dunes. The metalmarks visit some buckwheats but not others, especially avoiding those near the old vineyards, possibly due to the residual sprays. In addition, the metalmarks prefer certain microclimates to others--ones that have a special mix of sunlight, protection, and other vegetation. But understanding the exact recipes for their preferred sites is not known.
Communities are popping up in the spirit of Stein's 'mosaic'. In the midwest there are several planned communities, including older communities, that have decided to rebuild, that have large community gardens, preserved open space, and intentional landscaping to preserve hedgerows and meadows.
School children can make surprising changes. Here in my community in the north Bay area around San Francisco, a fourth grade class decided to study a locally endangered fresh-water shrimp. They researched the problem and decided a cattle crossing across a local creek, as well as restored creekside vegetation, would be the best way to help boost the shrimp's population. Some of the class sent letters to raise money and awareness, some talked with the local ranchers, some planted new vegetation, while others monitored the creek and the shrimp. The one year project turned into a four year project, with each successive fourth grade inheriting it. The class raised enough money to build the bridge, restore the creek, and do other restorative work. They became nationally recognized and several students were sent to Washington D.C. to speak to politicians. Their project served as a model for project-based learning.
Elizabeth Donnelly, creator of The Journey North, an on-line program for school-aged children, involves more than 25,000 children a day in tracking the journeys of several migratory species. By simply logging on, students and teachers alike can follow the progress of monarchs, bats, and other backyard wildlife, and make entries with their observations. If backyard gardeners were to become involved in similar programs, we could have volunteers doing yearly counts of migratory species, following their routes, and helping to ensure continuous nectar corridors. These groups could link up with others farther down the line in order to spot any hazards or barriers along the corridors.
What about pollinator gardens? How effective are they? One pollinator garden an ecosystem does not make. A small garden or even series of gardens cannot possibly duplicate or conserve precious populations of threatened species. But we can learn several important lessons from them. First, combined with other larger efforts to save wildscape, pollinator gardens can be a laboratory in which to learn new techniques of healing and preserving our eco-systems. Second, they are a pulse on the local habitat and it's health. And last, along with our neighbors and friends, these gardens preserve a link to our own sense of wonder and wildness.
If we and our children stay engaged in the brillance of nature, we will be moved to protect it. Watching birds, butterflies and bees in our own backyards may stir our experience and help raise our voices to protest pesticide poisoning, or unbridled development.
Thirty years ago, environment education was a local or national phenomenon. Now educators speak about environmental damage and it's healing as a global necessity. There are 16 families of butterflies who regularly visit flowers, 15,000 species of wasps which pollinate, at least 45 families of flies visiting flowers, 1,500 bird species pollinators, and 75 species of bats visiting flowers. In all, some 130,00 to 200,000 invertebrate and vertebrate species regularly visit flowers which depend on animals for cross-pollination. "Pollination is amazing," says Ian Cox, botanist from Brigham Young University. "It's sort of like the sun rising. We've always taken it for granted. But if you lose a species of bee, you can't get it back. I think it's safe to say we're in trouble. What we don't know is how big the trouble is."
For an in-depth presentation of the crisis in our world's pollinator's and plants, please read The Forgotten Pollinators by Stephen Buchmann and Gary Nabhan.
Leslie Patten is a landscape designer in San Rafael, Ca. She is the author of BioCircuits:
Amazing New Tools for Energy Health.
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