What “Took Out” the Dinosaurs and the Bees?

18 September 2014

            About 65 million years ago, the dinosaurs went extinct.  They weren't alone.  A large number of bee species went extinct as well.  The question: What took out the dinosaurs and the bees?

          The dinosaurs’ extinction is tricky because 65 million years ago, about 90% of the dinosaurs had already died out.  What was killing them?   A lack of oxygen.

            Remember in the film Jurassic Park.  Dino DNA was discovered in a mosquito sealed in a prehistoric piece of amber.  Well, I don’t know if anyone will ever find good dinosaur DNA, but scientists have found a lot of air bubbles in prehistoric amber.  So many air bubbles that it’s possible to know how much oxygen was in the prehistoric air. 

            When dinosaurs ruled the world, a whopping 35% of the air they breathed was oxygen.  This allowed them to have a relatively inefficient method of breathing.  On the other hand, mammals, like us, had, and have, a very efficient, low-energy respiration system.  But, then, so do insects, like bees.

            65 million years ago, the oxygen in the earth’s air was settling down to its current level of 23%.  The decline from 35% to 23% had spanned millions of years.  And throughout those millions of years, every time the oxygen in the air went down, the number dinosaurs alive on earth went down.

            Then, as the saurian’s teetered on the brink of extinction, something catastrophic happened.  A meteor hit the earth.  Meteors had hit before, but this wasn't your average meteor.  Any relief map of the U.S. will show Arizona’s Meteor Crater.  This easily visible monster of a crater (a bit under a mile wide) was made by a 160 foot-wide piece of space rock when it hit the earth. 

Meteor Crater Arizona

            But the meteor that hit the earth 65 million years ago was a bit bigger – over 40,000 feet wide.  And, when it hit, it was traveling at a speed of about 65,000 mile per hour.  

            This meteor made its mark.  It would have been easier to find its mark if it hadn't landed in the Atlantic Ocean just off the Yucatan Peninsula in Mexico.  The ocean-bottom crater stands as a testament to the size of the meteor and the event. 

Chicxulub Meteor Strike

            The result was dust.  More dust than you could ever imagine.  Blown into the earth’s atmosphere, the dust darkened to sun so much that the earth suffered a night that lasted more than a year. 

            Plants need the sun to survive.  A large chunk of the plant life on earth died.  The animals that fed on that plant life followed quickly.  But, a smaller animal had a smaller appetite and a better chance to live through that long night. 

            The dinos weren't small.  Extinction followed -- quickly.  But a lot of dino’s might have made it through this dusty night in the old days -- those oxygen-rich days when 10 times the dinosaurs roamed the earth and . . . breathing was easy. 

            But what about the bees?  Plants, and their nectar-filled blossoms, are the bees’ “bread and butter.”  And, for plants, the bees are the great pollinators.  Without pollination, there would be no seed for the next – lighter and brighter – season.  Many plant species didn't stand a chance. 

            But how can we know what happened to the bees?  The prehistoric bees left few fossils.  Unlike their prehistoric fellows, the dinosaurs, the bees didn’t hang-out around tar pits and other dangerous locations favorable to fossil formation.  Bees prefer flowers, nectar and sweet tree saps.  Sweet saps?  What happens to sap when it ages a few million years?  It becomes amber.  And, yes, some intact bee remains from prehistoric times have survived.

Prehistoric Carpenter Bee (Xylocopinae)

            Today, there is one “subfamily” of bees, Xylocopinae, with a traceable evolutionary history going back to the age of the dinosaurs -- the Cretaceous Period.  Most of the members of this bee subfamily are carpenter bees.  “Carpenters” are found throughout the modern world.  These bees look a bit like bumblebees.  The name “carpenter” comes from their nesting habits.  These bees build their nests by boring into dead wood – a habit that doesn't always endear them to homeowners.   

            The surviving modern descendants of these prehistoric bees are important to researchers.  We may not have so many bee fossils.  But we do have a sample of the DNA from a prehistoric bee.  We, also, can get a sample of the DNA from its modern descendant.  Comparison and the ancient and modern DNA can tell us a lot about the past.

            The study and comparison showed that the population of at least one group of bees suddenly and seriously declined at the just the time of the meteor strike – 65 million years ago. 

            The dino’s extinction may have more to do with oxygen-poor air than a meteor strike.  But the meteor strike left drastically fewer bees alive on earth.  But, for researchers, this isn’t the end of the story.  With this information, they are hot on the trail of the answers to other questions. 

            We know a lot about the numbers and types of plants that went extinct at the time of the meteor strike.  But, by carefully comparing the timing of the plant losses and bee losses, researchers hope to piece together just what that dusty atmosphere was like and exactly how long it lasted.

            Finally, the story of the prehistoric meteor has recently been pumped full of new life.  Not from a new discovery, but from some name-changing.  A few researchers have decided that the meteor was so big, that it should be reclassified as an asteroid or comet.  This may make little difference to the story of what happened to the dino’s and the bees -- but another day, another headline.

M Grossmann of Hazelwood, Missouri & Belleville, Illinois

18 September 2014

About the Author

When Good Bees Go Bad -- Bumblebees Turn to Nest Piracy

8 May 2014

            Because of their decreasing numbers, bees have been getting a lot of sympathy lately.  The bumblebee has taken a hard hit.  This wild, foraging bee has been the direct victim of human development. 

            Our new “intensive land use” style of agriculture has led to the elimination of fallow fields and breaks.  The bumblebee used to depend on the wild grasses and brush that grew in these open areas. 

            Then, at least in North America, a developing obsession with “neatly manicured” landscaping of any and every public area has resulted in the regular mowing of wild grasslands.   Again, this leaves the bumblebee to forage elsewhere. 

            In North America, alone, the bumblebee population have declined by millions.  At least it has everywhere, but in the mountains – where farms are rare, and wild grasses are valued for their beauty.  The Rockies are, still, the home to a healthy population of bumblebees    

            The bumblebee is a loner, unlike like its “oh, so social” cousin, the honeybee.  Or, at least, bumbles is the nearest thing to a loner that a bee can get.  The bumble bee forages for food alone.  These bees don’t build or maintain hives or even permanent nests.  A new nest is built and abandoned yearly.   That does seem like a lot of work.

            The bumblebee also has its predators.  One of those predators lives in the forests of the Gwanak Mountains not far from Seoul, South Korea.  It’s a bird called the “Varied Tit” (Parun varius).  Recently, South Korean conservationists have been provided nest boxes for these birds in the area around Seoul.  Some time after placing the nest boxes, the conservationists returned for a check.  They were in for a surprise.

            Over 20%, one in every five, of the nest boxes weren't occupied by birds.  Instead, bumblebees had made their nests in the boxes.  Were there too many nest boxes -- more than new bird families needed?  Was that why the bumblebees took-over the “unused” boxes?

            Guess again. 

            The bumblebees hadn't built the nests in the nesting boxes they occupied.  Every nest had been built by the birds.  Were the nests left over from the previous year?

            Guess again. 

            All the nests were new.  Each had been built by the birds and, then, abandoned.  Did the bumblebees just sort of “happen by” and discover the unused nests and move in?
            Guess again.

            Consider . . . imagine you are an experienced hunter who hunts, tracks, and kills mountain lions.  You know your pray, and you aren’t so afraid of the mountain lions while you're hunting them.  But what would happen if you went home only to be awakened in the middle of the night by the sound of mountain lions growling in your bedroom.  You'd do what I'd do -- get out of the house fast.

            This brings us back to our nesting bumblebees.

            It seems that bumblebees are smarter than we thought.  These bees knew they could, sometimes, scare a predatory bird away with their loud buzz.  Sometimes.  And, sometimes, not. 

            But the bumblebees had an even better idea. 

            These bees waited for the birds to build a nest -- one particularly suited to the bumblebees’ needs.  Then, when the bird was out, a bee or bees would sneak into the nesting box and hide inside the bird’s nest.  When the bird came back to relax in their nest-box/bedroom, the bumblebees would start their fullest out-loud buzzing.  And bumblebees are famous for their loud, vibrating buzz. 

            The terrified birds, thinking they were trapped and about to be stung, flee the nest and never come back.

            Then, the bumblebees move in and set up housekeeping in their new nest.

            Again, bumblebees are smarter than we thought.

M Grossmann of Hazelwood, Missouri & Belleville, Illinois

8 May 2014

About the Author

The Bee Rescue – Some Old Solutions to Some New Problems

13 March 2014

In an effort to maintain the population of bees and other pollinators, the United States Department of Agriculture has budgeted $3 million.  Most of the money will go to ranchers, farmers and beekeepers in a conservation effort to preserve and expand pollinator habitat.

WHAT’S HAPPENING TO THE BEES?

Bee populations have been declining for over 7 years now. First, termed a “disappearance,” then, a “die-off.” the continuing depopulation is, now, formally referred to as “Colony Collapse Disorder.” The continuing decline has been both rapid and widespread affecting perhaps the entire world.

Bees get a lot of scientific attention because they are vital to American agriculture, which is vital to the American economy. Without bees, production of some of our most profitable crops would be impossible. Every few weeks, a news article announces the discovery of “the cause” of the threatened bee “extinction.”  In fact, there probably isn’t a single cause. The current die-off seems to be the result of several factors working together.

The puzzle goes like this. A bee (1) has a parasite like varroa mites; (2) is exhausted by transport over long distances; and (3) is exposed to a particular pesticide. Alone, none of these factors would kill a bee. Even all of these put together wouldn’t kill a bee. However, all of these put together might weaken the bee’s immune system. Then, with a compromised immune system, the bee contracts, and dies from, a completely unrelated disease. That disease is the final cause the bee’s death. However, the underlying cause is an immune system compromised, not by one factor, but by a particular combination of several factors. For now, that combination remains a mystery.

A SHORT HISTORY OF AMERICAN AGRICULTURE

Modern agriculture has come to be dominated by a particular style called monoculture.  The modern farm is a study in intensive land use with about every square foot of available soil used for the continuous cultivation of crops – or more precisely a signal crop.  This modern style has little in common with the traditional agriculture of even a generation ago.

In the past, the typical farm included a fair number of fallow (unplanted) tracts of land in which wild brush and unmown grass were allowed to grow.  These tracts served several purposes.  They provided “breaks,” uncultivated buffer areas between cultivated fields of crops.  First, breaks slowed or prevented the spread of disease from field to field.  And, second, breaks prevented the seeds of one kind of crop from creeping into fields planted with another.  The third purpose of keeping some land fallow (unused) was to prevent soil depletion.  The practice of letting some fields “rest” for an a season was called crop rotation, which helped prevent a loss of, or restore,  fertility to tracts of land.

Traditional agriculture had always avoided modern monoculture’s practice of planting only one kind of crop.  The traditional reason for planting several different kinds of crops was, again, a sort of insurance against the spread of disease.  While one kind of crop might fall victim to disease, another would be less susceptible and survive to produce a much-needed yield at harvest.

What happened to traditional agriculture?  Advances in chemical fertilizers, herbicides and pesticides have dramatically reduced the need for crop rotation and fallow tracks of land as buffers.  But this created another problem.  The modern farm needs bees just as much as the traditional farm it replaced.  And bees need habitat.

DO BEES NEED HABITAT?

When we think of bees, we tend to think of the hive-dwelling honeybee.  The honeybee seemed to fit in perfectly with modern monoculture.  Like everything else needed by the modern industrial farm, when you need bees, you just order them “brought in.”  Beekeepers truck bees, sometimes hundreds of miles, to various locations during pollination season.  Then, the bees are trucked out when pollination is over.  At least, that was the plan before CCD and honeybee depopulation became a reality.

But, with or without depopulation, what’s with “habitat?”  The only thing honeybees need is a hive, a beekeeper, and the beekeeper’s truck.  Right?  Well, not quite.  Honeybees aren’t the only pollinators.  Worse, honeybees can’t pollinate some cash crops including certain varieties of tomatoes, cranberries, almonds, apples, zucchinis, avocados, and plums.  For these crops you need bumblebees.

So, why not truck-in some bumblebee hives?  And there’s the problem. Bumblebees don’t live in hives.  The plump bumblebee is the nearest thing to a loner within its social species.  Bumblebees don’t build permanent hives.  They build nests that are deserted for a new location on a yearly basis.  The bumblebees don’t forage (search for and find food) in swarms, but wander alone from flower to flower in open grasslands.

On the traditional farm, these wild bees made their nests in fallow tracks of grass lands or break areas between cultivated fields.  Because the bumblebee’s service as a pollinator is only needed seasonally, these bees survived during the rest of the year by foraging in the same wild grasslands in which they built their nests.

THE HABITAT VANISHES
Monoculture changed all that.  Fallow tracts, breaks, and buffers vanished with every yard of available soil planted with a crop.  Even the small islands of wild grass along the farms paths and roadways were pressed into service.  And the bumblebees left.

What did we lose?  A lot.  The bumble’s unique style of pollination is required, and accounts, for about 3 billion dollars in produce each year.

Fresh off the farm, the bumblebee made its way to the city or, at least, to more populated areas to find the welcome mat missing.  Modern urban and highway landscaping favors a neatly manicured look that requires the elimination of the wild grasslands required by the bumblebee’s lifestyle.  In parks and even around highway overpasses, that great enemy of bumblebee habitat, the lawn mower, doesn’t destroy the grass, but prevents the appearance the blooms and blossoms on which the bumblebees depend for food.  And worse, the lawn mower is the arch-enemy of bumblebee nests.

When the habitat vanished, so did the bumblebee.  Beginning in the late 1990’s, these bees all but disappeared from a vast area of their range extending from the Pacific Coast of California north into British Columbia.  Only recently have there been sightings of even a single bumblebee in several states that once supported an enormous population.

THE MOUNTAIN BEE?

It is said that those who felt uncomfortable in “civilization” used to become trappers and wander into the mountains — earning the name “mountain men.”  Well, maybe bumblebees did the same.  As these bees almost completely disappeared from their lowland range, their numbers were, and are, unaffected in the North American Rockies where they continue to live and thrive.  Mountains are not favored for agriculture and the rough beauty of mountainous areas is only enhanced by wild growing grasslands.  The mountain habitat is well within the bumblebees comfort zone.

THE USDA & A CHANGE IN ARGI’S “CULTURE”?

With all the developments in the efficiency of modern agriculture, it is a little surprising to read of a USDA spokesman discussing the use of cover crops, rangeland, pasture management and other practices that dropped out of modern agriculture decades ago.  But the purpose behind the reintroduction of crop rotation, breaks, and buffers makes sense if the purpose is to preserve native pollinators, most prominently the often forgotten bumblebee.

Without effective pollinators, there will be no harvest in spite of the most intensive and efficient use of the available land.  The USDA spokesman explained that these “new” practices “are expected to provide quality forage and habitat for honey bees and other pollinators, as well as habitat for other wildlife.”

M Grossmann of Hazelwood, Missouri & Belleville, Illinois

11 March 2014

About the Author