Monday, August 30, 2010

Black Cherry Trees Invade Europe

Black Cherry flowers
We have long known that plant and animal species are successful in becoming invasive when they arrive in a new land without their usual predators.  Now there is more evidence to support this theory.
Black Cherry have long been successful in growing in our forests, sometimes to the point that they are sometimes considered a nuisance species.   Like most native species, they have reached a a balance with their neighbors without out-competing them. Our black cherry trees however have become an invasive species in Europe.
Pythium is a fungal pathogen which causes a disease in black cherry trees called damping-off disease.  The disease kills seedlings in fields and greenhouses.
Studies reported in Sciencedaily.com found that Pythium could be found in 20 comparable forests in North America and in Europe.  However, its ability to kill trees was far less in Europe's forest's strain.
"Reinhart and colleagues tested the virulence of each Pythium isolate. They then used DNA sequencing to identify each isolate. They found that some non aggressive Pythium types were common in both ranges, but aggressive types were found only among samples from the tree's native range."
This study suggests that Pythium serves as a natural control in our forests to keep the population in balance.  Human pathogens such as E. coli and influenza virus vary in their virulence or ability to cause disease.  This is evidence of the same mechanisms in plant fungi.

Sunday, August 29, 2010

Egg Shell White?

Wild Turkey Eggs
What looks like a white egg shell to us may be an egg of a different color to a bird.  This is because birds see more color than we do.  According to livescience.com, ultraviolet pigments that are invisible to us may help birds distinguish between their eggs and those of another species.
"Unlike humans, birds can see ultraviolet (UV) light, and they have four – rather than three – color receptors in their eyes, allowing them to better distinguish between hues."
While we can recognized many of the differences between different eggs, we can't recognize the UV spectrum of short wavelength light seen by birds.  Nest parasites such as cowbirds and cuckoos lay their eggs in other birds nests.  Unsuspecting birds may nurture these eggs to the detriment of their own eggs.  Scientists suspect that the differences in UV colors play a part in the recognition and rejection of  these foreign eggs.
The article discusses the coloration of egg shells by two pigments and the mysteries of how and why these developed.  The basic egg is white from its calcium carbonate.  Any color which appears, solid or speckled, comes from a mixture of "blue-green biliverdin, and red-brown protoporphyrin, which are both breakdown products of hemoglobin."

While different colored eggs allows species to detect their own eggs, the colors also may serve to camouflage eggs from predators, act as a sun block or actually strengthen the shell.  Even a single bird's eggs may vary in color as the last eggs may have more speckles as the supply of calcium for egg shells is depleted.  Wikipedia on egg biology



Mysteries remain.  We are all familiar with the beautiful powder blue eggs of bluebirds, yet 5% of nestings produce all white eggs.  At times there is a slight pink or bluish tinge to the eggs but all the eggs will be the same color and produce normal colored chicks.  Apparently a bird will always produce the same color eggs.  If a egg of another color appears in the clutch it was dumped by another bird. 
Bluebird eggs- white

The biology and genetics of bluebird egg color is still in debate.  Some birds hatched out of white eggs subsequently lay blue eggs.  Sialis.org  has a lot more information on the subject.

Friday, August 27, 2010

Horsehair Worm

You may recall the amazing video we previously posted showing multiple parasitic wasp larvae emerging from caterpillars like something out of Alien.  How about an equally startling finding- stepping on a cockroach and facing this creature crawling out of it?  Tim Smith discussed this horsehair worm in his Fresh Afield blog in July.
I have seen these adult worms swimming around the edge of creeks and ponds but wasn't aware of their other life.  Their larvae emerge from eggs and then penetrate their hosts such as crickets, grasshoppers, cockroaches or beetles.  They inhabit spaces between their host's organs, absorbing its blood and lymph borne nutrients through their skin.
After several molts, they are ready to crawl out of their host (or emerge when it is stepped on as above).  They then start a free life in a moist environment, looking for love.  When they encounter a mate, they form a tight knot together, leading to their other name, the Gordion worm.   It is doubtful that they are aware that Alexander the Great sliced through the Gordion Knot or they might try another strategy.
You might think about them the next time you think about killing a cockroach- but I doubt it will stop you.
Details are in Wikipedia.

Dobsonfly is not a Fly

Dobsonfly- click to enlarge
When is a "fly" not a fly? When its name runs together, such as dobsonfly, mayfly, dragonfly, etc.  True flies including mosquitoes and gnats are distinguished by a single pair of wings.  Their common names are always separated such as house fly or fruit fly.
A News-Leader MDC article in July discussed the Dobsonfly (remember, it is not a true fly).  I had just identified one of these which had landed on my truck.  It is uncommon to see these adults which do not eat and live for only a few days.  They are five inches long nose to wing tips which extend far beyond the tip of the abdomen.
The adult male has impressive pincers used to grasp the female during mating.  They are so long that they don't have the leverage to pinch your fingers.  Not so for the female, whose short pointed pincers can hurt you.
Hellgrammite- Wikipedia
Dobsonfly larvae, called hellgrammites, are commonly found in streams and river bottoms and are beloved by stream fishermen.  These primitive looking creatures also come with a set of impressive pincers.  They live up to four years, going through molts and reaching up to four inches in length.  They are apparently considered a delicacy by trout and smallmouth bass and therefore of interest to the fishing set.
The hellgrammite breathes with gills along its sides and lives off of stream creatures which it grabs with its powerful pincers.  Rural children had a measure of bravery. It was tested by putting a finger under a rock and pulling out a pinching hellgrammite before pulling it off with the other hand.  Finally the hellgrammite crawls out of the water to pupate, forming the cocoon in which it will survive the winter.  Come spring, the Dobsonfly will emerge to resume the cycle.

Thursday, August 26, 2010

Insect Eggs

Zebra longwing butterfly egg- NG
The latest issue of National Geographic has an story on insect eggs.
You can argue that insect eggs are the seeds of life, for without insects there would be no human life on earth.  Love them or hate them, insects are a critical part of the food chain and the web of life on earth.
These tiny remarkable structures are nearly invisible to us in our daily encounters with nature.  Demonstrating butterfly eggs at Springfield Conservation Nature Center's Insectorama last night, I didn't encounter a single adult who had ever seen an insect egg although they are constantly around us.
Where can you find insect eggs?  Look for them buried deep in wood by the female's ovipositor.  Also in soil, on leaves, floating in the wind, suspended by fine threads or attached to the backs of flies.  Some even lie in water, breathing through long tubes.
Life is hard if you are an egg.  You are a delicacy to surrounding life forms, while others will stick their eggs in you to feed their next generation.
The National Geographic article gives a brief overview of these complex structures.  The whole photo gallery can be viewed at this accompanying web site.

Wednesday, August 25, 2010

Butterfly House

The Bill Roston Butterfly House at Close Memorial Park has been humming with activity since May.  Actually the hum is more a murmur of amazed children and adults, seeing the whole life cycle of butterflies up close and personal.  Frequently they can see this on a single plant as a butterfly flutters between heads to deposit eggs on a plant all ready hosting several instars of caterpillars.
Occasionally an excited child will point out a new emergence from one of the many moth cocoons or butterfly chrysalis in the house.
Master Naturalists have been heavily involved this year in the project.  Many listed below have served as docents in the house during weekly hours of operation.  Others have manned the Caterpillar Petting Zoo and Lifecycle stations during the Butterfly Festival.  Also some such as Buck and Charley have risked death and injury (well then, maybe ticks and chiggers) while tromping through the wild collecting fresh butterflies for the house.
Hands on Experience
The House is open weekends from 10 AM to 6 PM, Tuesday and Wednesday 5:00 to dark, and to groups by appointment (860-8272). For more information got to
Thanks to the following MN crew:
Rose Atchley, Doris Ewing, Caryn Fox, Carl and Janet Haworth, Karolyn V. Holdren, Sue Jeffery, Connie Johnson, Buck Keagy, Barb and Bob Kipfer, Steve and Linda Kittle, Joe Kleiber, Marlyss Simmons, Carol Snyder and Sherryl Walker.

Tuesday, August 24, 2010

Plastics Potpouri

Our Oceanic Garbage Patch 
We have all heard of the Great Garbage Patches floating in the oceans.  One question has been why the patches are not increasing over 20 years with increasing plastic production and trash dumping.  This report in Live Science suggests that one reason may be that the plastic pieces are breaking down to particles too small to be retrieved in their nets.  While we may envision a huge floating island of bottles and bags, the area apparently looks normal to the naked eye.  The nets pick up fragments as small as 0.3 millimeters (think a period in this paragraph).  Fragments are sorted and counted by students during the Sea Education Association's SEA Semester annual voyages.
"The term "garbage patch" does not necessarily mean a visible island of trash floating on the waves, researchers said. Only 62 percent of net tows by ships have contained detectable amounts of plastic.
"What we're collecting are really small fragments of plastic from larger consumer items," Lavender Law explained. "If you're on the deck of a ship, you normally can't even see the plastic pieces."
Each half-hour net tow typically turned up just 20 plastic pieces equivalent to about 0.3 grams in all. By comparison, a U.S. nickel weighs 5 grams."
The tiny fragments have bacteria living on them which are not normally found at the oceans surface.  Do the microbes degrade and eventually dissolve the plastic, use it as food, or just a place to attach?  Stay tuned for further research.


BPA or Not-BPA?
 According to a column in "Harvard School of Public Health" researchers have found that college kids who drank from polycarbonate bottles showed a two-thirds increase of the chemical bisphenol A (BPA) in their urine." This has several interesting implications.

The good news is that (a) the levels were slightly higher than a trace, way below the "harmful" range and (b) it was outward bound in the urine.  The bad news is that it did pass through the bloodstream on its way to the kidneys and we don't know how much was stored in fat along the way.  Since we as a nation have accumulated more fat in recent decades, the national BPA storage facilities have increased.  A cynic could say that we may be reducing the environmental levels by our habits.

Does BPA stay in the body?  An article in Environmental Health Perspectives Journal suggests that it does.
"Vandenberg et al. (p. 1055) reviewed 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, and found that these studies overwhelmingly detected BPA in adults, adolescents, and children."
Does it matter and what can you do about it?  The risks of BPA in humans is currently unknown.  The article entitled Live Science has information on the numbers on containers that identify which plastics contain BPA.  Meanwhile, recycle and live green as the modern world will let you.

Monday, August 23, 2010

Alligator Snapping Turtles

Ritter Spring's alligator snapping turtle
Melvin Johnson sent me this interesting story from observations he made at Ritter Springs Park, confirming their suspicions that there was an alligator snapping turtle living in the pond.
"Both Kara Warren and I were sure of what we were seeing.  Finally, after some six years of  my trying to get photo verification documentation, MDC has verified from the below photo that there are alligator snapping turtles at Springfield – Greene County Park Board’s Ritter Springs Park."

This makes Ritter Springs Park unique in its natural habitat as it already contains federal endangered gray bats and Missouri bladderpod.

Alligator snappers are rare in Missouri.  They are up for review for the “Concern List” in Missouri as well as being up for review and nomination to the Federal Endangered Species List.  They are a protected species in Missouri.

Alligator snapping turtles (Macroclemys temmincki) are described in Wikipedia as being one of the largest freshwater turtles in the world.  They are carnivores, eating anything that they can catch, including both live and dead meat.  Much like me, they can eat a vegetarian diet when meat is not available, but prefer meat.  The average adult size is around 175 pounds with a 26 inch shell length, although several are known to weigh in at over 235 pounds. 

If you get to Ritter Springs you might be lucky enough to see this big boy.  For a more urban experience look in the tank at the Bass Pro Shop.



Wednesday, August 18, 2010

Miscellaneous Stories

Mockingbird Mischief

I recall a KSMU interview by Mike Smith a few years ago, discussing mockingbird stories.  Someone told about the bird outside their bedroom window that had perfected the sound of their alarm clock, only the bird was set for much earlier than the alarm.  Another bird had learned to mimic the sound of their flushing toilet.
Wonder how and why they develop this talent?  There is more on this in this Freshare.net article.  Or for a concert of their songs, hit this Birdjam site. 

Oaks Farm Bacteria

What do you do if you are an oak tree trying to grow in acidic soil without accessible mineral nutrients?  You might try growing bacteria around your roots that can breakdown inorganic minerals so you can absorb them.  More on this at Freshare.net.

Monday, August 16, 2010

Cyrano Darner- Our Dragonfly

Today it is time to learn about the dragonfly that is the emblem of the Missouri Master Naturalists.  Cyrano Darner - Nasiaeschna pentacantha is also known as the Harlequin DarnerThey tend to fly slow patrols over lazy streams and ponds in late morning, chasing off other dragonflies.  Their peak flying time is June and July when they may be found feeding along woodland edges and streams.
Like damselflies, dragonflies larvae live in water.  While damselflies are usually close to water, dragonflies are stronger and may be found farther from water.   Adults and larvae are predatory, with the adults feeding on small flying insects which they catch on the fly.  They are referred to by the endearing term "mosquito hawk."  

Dragonflies have narrow bodies, thicker that the needle-like bodies of damselflies, making them threatening in appearance  but they are harmless to humans.  Their membranous wings which are frequently clear, are held out horizontal to their bodies at rest. 

Missouri Conservationist 2000 had this information on how to catch a dragonfly by hand. 
"Approach them with one hand making erratic circles in front of the insect. A few failures will indicate how close you can get.  Slowly move the other hand in from the rear and pick the dragonfly up by its tail. Then switch your hold to its thorax. When calmed down, they will accept and eat offered insects, such as mosquitoes." Editor's note:  There were no instructions on how to hold the mosquito you are feeding it.
Identification of these creatures is aided by the program at Discoverlife.org.  By choosing wing patterns, tail shape, eye color, etc, you may be able to narrow your search.
Wikipedia has a lot of general information on dragonflies.
Henderson State in Arkansas has a great website with photographs of the Odonates (Damselflies and Dragonflies) of Arkansas
Thanks to Lee Ruth for the picture of our Master Naturalist symbol.

Sunday, August 15, 2010

Hummingbird Rescue

I was recently sent this story by our partners at Audubon.  It gives the back story of the five minute video below of a hummingbird baby's rescue.  While we know to leave baby birds that fall from the nest alone, this one was handled intelligently.

You may recall from the July blog Hummingbird Hows that a newborn hummingbird weighs almost twice as much as its poor beleaguered mother.   Note the size of the baby compared to momma. 
"This is actually a pretty amazing story about a baby hummingbird that was found on a sidewalk.  He couldn't fly, so I took him under my wing.  At night, he would come home to our house for safety.  During the day, he was in the backyard of the house near where I found him.

About 4 days after I found him, I was holding him in my cupped hands when his mama came by to feed him.  She had seen me around, I guess, because she just flew over, perched on my hand and then fed him.  This happened a number of times, so I called a friend who is good with a video camera, and he came over to film some of the amazing goings on that I told him about."
I hope this is enough info to give you some context for the video we posted to YouTube at http://www.youtube.com/watch?v=l7xBLvMIBZU."

Saturday, August 14, 2010

Impala and Elk

Impala and Cheetah
"The lion and the calf shall lie down together but the calf won’t get much sleep."
                                                        - Woody Allen

This story from the Daily Mail of a trio of cheetahs making friends with a young impala is touching.  Fortunately they had just finished dinner.



Elk Restoration in Missouri?
"This ridge appears to be a favourite haunt for elk and bear, which have been frequently seen in our path. The enormous size of the horns of the elk give that animal an appearance of singular disproportion, but it has a stately carriage, and in running, by throwing up its head, brings the horns upon its back, which would otherwise incommode, if not entirely stop, its passage through a thicket."
While this may sound like a passage from Lewis and Clark's journals or an early description of Yellowstone, it is from Missouri.  The date was November 19, 1818 and Henry Rowe Schoolcraft was traveling along the North Fork River.
Now there is interest in reestablishing elk in this area of the state.  You can learn more from this MDC site.

Friday, August 13, 2010

Jellyfish- Fresh Water and Foul

Jellyfish- MDC
The Thursday News-Leader carried an MDC story about Freshwater Jellyfish that was news to me.  These exotics were accidentally introduced in the 1800s from China, possibly with importation of exotic fish.  They are found in still waters of lakes and ponds, blossoming unpredictably in some summer months.
"Freshwater jellyfish are about the size of a quarter. The best time to see them is in mid to late summer floating or swimming at the water's edge. Sightings occur in a somewhat yo-yo cycle. Numerous sightings one year will be followed by no sightings at a site for a year or more. This is one of the mysteries associated with the organism."
Jellyfish are the adult stage of their life, much like the caterpillar-butterfly life cycle.  After spending most of their life as polyps attached to the bottom structures of quiet water, they split off a bud which drifts off as a jellyfish, reproducing by releasing eggs or sperm which fertilize and settle on the bottom to start the cycle again.
Jellyfish eat zooplankton, worms and other small creatures.
"Once prey come in contact with the tentacles, venom is injected from the tentacles and the paralyzed organism is brought into the jellyfish's mouth and digested. The stings these tiny tentacles inject pose no threat to humans."
Once again, the biodiversity of the Ozarks amazes me.  Intended or unintended, we seem to have it all.  I am waiting for the first report of a polar bear any day now.

Jellyfish Gone Wild
Smithsonian has a big article on jellyfish titled The New King of the Sea.   It highlights the rapidly exploding jellyfish populations in recent years.  Not only are numbers of jellyfish expanding exponentially, but the previous seasonal patterns are disappearing as masses of jellies are showing up any time of the year.  The shear bulk of these swarms has had a significant impact on human and marine activities as described below.
"Nightmarish accounts of “Jellyfish Gone Wild," as a 2008 National Science Foundation (NSF) report called the phenomenon, stretch from the fjords of Norway to the resorts of Thailand.  By clogging cooling equipment, jellies have shut down nuclear power plants in several countries; they partially disabled the aircraft carrier USS Ronald Reagan four years ago. In 2005, jellies struck the Philippines again, this time incapacitating 127 police officers who had waded chest-deep in seawater during a counterterrorism exercise, apparently oblivious to the more imminent threat. (Dozens were hospitalized.) This past fall, a ten-ton fishing trawler off the coast of Japan capsized and sank while hauling in a netful of 450-pound Nomura’s jellies."
The NSF 2008 report,  Jellyfish Gone Wild mentioned above lists many interesting jellyfish facts as well as the more dramatic incidents.
  • Twenty to forty people die in the Philippines each year from box jellyfish stings that can kill within three minutes.
  • Chesapeake Bay reports over 500,000 jellyfish stings each year.
  • One third of the weight of all life in Monterrey Bay is made up of jellyfish.
  • 400 vast Dead Zones in world oceans are too polluted for almost all life except jellyfish.
  • 500 million refrigerator-sized jellyfish float into the Sea of Japan daily during blooms.
These exploding populations can severely impact the vast waters they inhabit.
"During the 1990s, a voracious, invasive jellyfish-like creature known as the comb jelly was introduced into the Black, Azov and Caspian Seas.  Uncontrolled by natural predators, comb jelly populations quickly ran wild.  The rise of the comb jelly contributed to crashes in the populations of anchovies in the Black and Azov seas and to crashes of a small commercial fish known as kilka in the Caspian Sea.
How did the comb jelly damage the populations of these commercial fish?  By eating their eggs and larvae and by eating the same zooplankton prey they eat. "
As usual, the role of human activities in the dramatic increase of jellyfish population is unknown.  Whether "global warming," acidification of the seas due to carbon dioxide or pollution are major factors is unknown.  But in the words of the NSF report,  "The global influence of jellyfish on marine ecology warns all of us: Ask not for whom the jellyfish’s bell tolls; it tolls for thee."

Update 9-22-2015
The Ozarks Water Watch contains information on their presence in our local lakes. 
The NSF report Jellyfish Gone Wild is full of information on the life cycle of jellyfish as well as their swarming locations and impacts.

Wednesday, August 11, 2010

Birds Gotta Fly- But Where?

One of the frustrations of air travel is the inability to fly to nearby locations by a direct flight.  Birds have a similar problem.
Logic would tell us that birds are free to fly anywhere to find better food or cuter mates.  It turns out that they operate within the same boundaries as many ground based animals.  A Bird's Eye View on Freshare.net discusses research on flight patterns of Missouri's resident birds such as jays, woodpeckers and cardinals.  
Dylan Kesler, assistant professor in fisheries and wildlife at the University of Missouri’s School of Natural Resources has radio-tagged red bellied woodpeckers, then tracked and plotted their movements with GPS.  To quote:
Those studies provided preliminary confirmation of what has been suspected by conservationists since the 1990s – that birds make landscape-influenced flight decisions along paths where they can immediately dive into tree cover to escape predators and readily find food.
The research also revealed that the birds avoid large areas without trees. Such exposure can make them easy pickings for predators. These open habitat features include roads, rivers and forest gaps, as well as other man-made landscape features where there is no easy cover.
Highway W- Click to enlarge
Their research shows that the birds limited their flight to corridors of trees.  Now click on the picture of a typical "rural" landscape south of Ozark and envision their flight possibilities.
This has important implications in our time of habitat fragmentation.  We are steadily reducing their territory and fragmenting their populations.  How small is too small?  O nly time will tell.
I would encourage you to read A Birds Eye View and look at their maps. 

Tuesday, August 10, 2010

Purple Martin Megaflock

Photo by Chris Barnhart- Click to enlarge
Chris Barnhart put us on to the annual pre-migratory flocking of Purple Martins which are collecting at sunset north of Division at Old Orchard Road.  This is an annual event as they prepare for their trip south to the Amazon for the winter.  They routinely gather at various sites in North Springfield, covering the skies as they swoop into the trees for the night.  They are frequently mistaken for starlings flocking, but as swallows, their distinctive graceful flight is easy to distinguish.

You commonly hear that they eat lots of mosquitoes, but unfortunately it isn't true.  According to the MDC,
"These aerial acrobats catch flying insects on the wing.  They are not major predators of mosquitoes, which fly much lower than martins do.  A martin colony, however, may catch and eat several hundred beetles, horseflies, grasshoppers, dragonflies and wasps each day. Because inclement weather can greatly reduce the availability of flying insects, an extended period of rainy or cold weather can cause massive mortality in purple martin populations."
Purple Martins are the largest North American swallow and are sometimes called "America's Bird. " Originally they were cavity nesters, but early Native Americans began providing them gourd homes and European immigrants took up the habit more formally.  Over time east of the Rockies they have become completely dependent on humans, living only in human provided martin houses.  Now there are Purple Martin Societies, blogs, clubs, magazines and a large commercial market for houses and other paraphernalia.  There is extensive information about their life at Purplemartin.org.
Pre-migratory resting- Click to enlarge
Purple Martins begin to arrive in Missouri in late March and follow the blossoming insect populations north all the way into Canada.  After monogamous mating, they raise their chicks in the summer and then fuel up for the return to the Amazon.  Their pre-migration flocks can measure in the hundreds of thousands.  Having lived in apartment houses, they are very comfortable clustering together on tree branches as they prepare for their big trip.

Currently they are filling the skies (See this map) around 8:10 and settling in around 8:30.  You can probably catch the show for another 10 to 20 days.

Thanks to Chris and Deb Barnhart for the call and the pictures.
More on Purple Martin dwellings is available at missouribirds.com
and a pdf file with house designs at mdc4.mdc.mo.gov/Documents/12199.pdf 

Monday, August 9, 2010

Radioactive Boars

Spiegel Online
Missouri has a feral hog problem which has increased over recent years which we discuss below.  So far the damage hasn't reached the levels seen in Germany where the boars all but glow!
Hunting native wild boar in Europe has been a sport for thousands of years there, and its meat is still a popular menu item.  Spiegel On Line reports that in recent years, an increasing number of boars are contaminated with radiation, the results of the fallout of Ce-137 from the Chernobyl disaster in nearby Ukraine.
Boar are fond of mushrooms and truffles which are particularly efficient at absorbing radioactivity, even as other vegetation's cesium-137 levels are falling.  By German law, the government must compensate hunters who shoot boar subsequently testing out with high radioactive levels.  This payout doubled to $550,000 last year.
Increasing numbers of wild boar are occurring across Germany.  Last year 650,000 wild boar were shot, breaking the previous record of 287,000.  This population explosion is attributed to milder winters and the increasing growth of corn on farms. Human encounters are becoming much more common.  "Boars have stormed churches, chased police, rampaged through stores and living rooms, knocked an elderly woman off a bicycle, attacked a wheelchair-bound man, dug up corpses, and caused as many as 25,000 traffic accidents a year." change.org
Feral Hog- Click to enlarge

Back to Missouri
Our feral hogs are genetically a mix of breeds, combinations of Russian or Eurasian wild boar (razorbacks) and an assortment of domestic varieties.  The population has been expanding over the last 20 years as European wild boar were raised for hunting in licensed shooting areas. Many hogs escaped or were released on public land, and by 2000 private landowners were complaining of damage. Hunters are encouraged to shoot feral hogs on sight. This MDC article goes into more detail.

Feral hogs cause a lot of agricultural damage as well as soil disturbance and they even devour wildlife such as ground nesting birds and fawns.  Best classed as omnivores, feral hogs eat about anything they find, including sheep and goats. They are frequently attracted to birthing areas and most often take lambs or kids. They consume these newborn animals so completely that there often is little evidence that birthing and predation have occurred.
Of potentially greater economic damage, they can transmit diseases such as pseudorabies and swine brucellosis to domestic hogs.  Infection in a domestic farm's population could require destruction of the whole herd,  which occurs around six times a year in the US.  Swine brucellosis has been found in wild pigs in ten states and is known as undulant fever in humans.

Everything you need to know about Feral Hogs of Missouri is at the MDC Feral Hogs site.

Sunday, August 8, 2010

Tumbling Creek Cave

Amazing Cave
On Saturday, an intrepid group of Master Naturalists* braved the heat to explore the land as well as the depths of the Ozark Underground Laboratory at Protem.  This remarkable 2600 acre site represents the incredible passion and chutzpah of its owners, Tom and Cathy Aley.
What else could explain the success they have had in buying a cave and spending over 30 years in protecting its 9 square mile watershed?  In their spare time they have invested in a wide variety of conservation projects, including an advanced septic system for a nearby school, all to protect a unique snail (and while they are at it, other unique threatened species and all the rest of the environment.
It is impossible to hear Tom's humor-laced lessons of the interaction of water, rock, chemistry and animals (humans included) without being swept along like water through our karst topography.  A brief description of the tour is found at their web site under Field Programs- Surface and Underground Tours.

Webworm- Jennifer Ailor- Click to enlarge
One highlight was finding the fungus webworm.  OK, it sounds like a weird highlight but stick with me.  They spin their webs of long vertical strands in small rocky shelves.  The tiny worm hangs suspended from a series of vertical silk threads which it travels across in search of small flies and other trapped critters which depend on bat guano for their imported nutrition. 
After 9 months of growth and development, it forms a pupa, much like a butterfly except a tiny gnat emerges.  The fungus gnat lives its brief anonymous life around the entrance to a cave.  After unseen mating, it flies deep into the darkness, looking for an area rich with bat guano.  There it deposits it eggs to resume the cycle.
Webworm-- Click to enlarge
The detailed Fungus Webworm story from Dr. David Ashley is here.

Webworm dining picture is here.
There is a story about Tumbling Creek Cave in Weird Missouri.

Survivors of the Expedition to Tumbling Creek include Marlyss Simmons, Allan Keller, Jaretta Beard, Caryn Fox and her husband Steve, Bob and Barb Kipfer, Billy Thigpen and Linda Coroleuski from Sierra Club and our fearless leader Jennifer Ailor.

Friday, August 6, 2010

Phytoplankton and You

Humpback Whales Bubblenetting- click to enlarge
A new study in Nature, reveals for the first time that microscopic marine algae known as "phytoplankton" have been declining globally over the 20th century.  They found a decline of almost 1% per year.  Why should we, far away in the Ozarks, care?
How about breathing?  Phytoplankton is tiny but its mass absorbs CO2.  Of more immediate importance to mammals, it produces half the oxygen we breathe.  
"Phytoplankton forms the basis of the marine food chain and sustains diverse assemblages of species ranging from tiny zooplankton to large marine mammals, seabirds, and fish." says lead author Daniel Boyce.  "Phytoplankton is the fuel on which marine ecosystems run.  A decline of phytoplankton affects everything up the food chain, including humans."

This trend is particularly well documented in the Northern Hemisphere after 1950, and would translate into a decline of approximately 40% since 1950. The scientists found that long-term phytoplankton declines were negatively correlated with rising sea surface temperatures and changing oceanographic conditions.
A more detailed explanation of these findings can be found in Science Daily.

The impact of phytoplankton decline on the planet is hard to predict but I would hazard a guess that it ain't good.  As the base of the oceanic food chain it is bound to affect fish and mammals such as whales as well as all species in between.  There will likely be far more losers than winners. Those of us at the top of the food chain should be concerned.
 
Mean global temperature anomalies- 1880-2001 NOAA
Baby Fish don't like CO2
 http://www.sciencedaily.com/releases/2010/07/100707091211.htm
 There is still a lot of healthy debate about the role of human activity in producing global warming.  Either way, there are two facts that can no longer be ignored.

  1. There is a global warming trend over the last 50+ years.  
  2. From Wall Street Journal- click to enlarge
  3. There is an increase in carbon dioxide in our atmosphere.  
In 2005, global atmospheric concentrations of CO2 were 35% higher than they were before the Industrial Revolution.  There are two main engines that remove carbon dioxide and convert it to oxygen- trees and phytoplankton.  We now have evidence that both are declining.  You do the math.

Tuesday, August 3, 2010

Polyphemus' Perilous Perch

Polyphemus- Click to enlarge
My granddaughter spotted this Polyphemus moth, clinging below a rock shelf by a little waterfall. It was in the shade all day, had a cooling mist off the waterfall and was out of reach to most of its normal predators.  Its wingtips were barely an eighth of an inch above the water but the view must have been worth the risk.
This moth probably was tired after a long night of courting.  Unlike most other lepidoptera, its lacks a functioning digestive system and never feeds.  It exists to breed and lives only six days, so it probably earned a rock with a great view.
Polyphemus, Antheraea polyphemus, is the second largest moth in Missouri.  Named for the one-eyed cyclops in Greek literature, it has a single large eye spot on each hind wing.

Wikipedia gives a lot more information including these facts:
  •  A Polyphemus moth caterpillar can eat 86,000 times its weight at emergence in a little less than two months!  It has several broods between May and August, its caterpillars feasting on 20 different tree species including maple and oak.  The caterpillar usually wraps a host plant leaf around its cocoon. 
  • Males can be distinguished by their feathery antennae,  which are more plumous than the females.  Yes, I know- I had to look it up too- its Latin for "full of down or feathers".  (see photograph) 
  • The females emit pheromones which the male can detect through its large, plumose antennae.  The pheromones are released at a species-specific time, referred to as the "calling time". This “calling time” can help prevent moths with similar pheromone chemicals from finding the wrong mate.  (MDC)  Polyphemus' calling time is between 11 PM and 1 AM, and again from 3 AM to dawn.*   
  • Males can fly for miles in order to reach a female. After the moths mate, the female spends most of her remaining life laying eggs, while the male takes off and may mate several more times.  Editors note: No surprise there!

    Note Feathery Antennae- click to enlarge
    * Butterflies and Moths of Missouri, Heitzman

Monday, August 2, 2010

Dog-Day Cicada Revisited

The continued cicada chorus has been almost deafening, reminding me that I hadn't been able to memorize their Latin names.  On further reading, I came up with the common names of the most frequently heard cicada so I am expanding the previous posting.


Scissor Grinder cicada
Annual cicada, aka dog day cicada are discussed in an MDC article.   
The cicada singing now are the Tibicen species .  These are familiar to most of us because of their stout green and black body.  Their transparent wings extend beyond their abdomen, looking like they could never get them off the ground.*
The males make a loud mating call to attract a female, varying between a rhythmic buzz and a rattle that is an insect version of "So, do you come here often?"  The sound emanates from specialized membrane organs on their abdomen.  The sound and time of day is unique to each species.  Play the sound files below and you will immediately recognize the sounds. 
  • T. robinsoniana (Robinson's cicada) makes this saw-like repetitive call (the loudest of any insect in North America), during the day.  It lives in forests and cedar groves.  When it starts its call, it is frequently joined by others in a mighty chorus.
  • T. chloromera (Morning cicada) makes its familiar call during the day, a chatter which slowly builds to a crescendo, then slowly dies away.  They tend to live in shrubs and tall weeds along creek banks.  They have a long larval underground life cycle, but since these overlap, there are adults around every year.
  • I know you will recognize the evening call of T. pruinosa (Scissor Grinder cicada), a rhythmic buzzing chirp, increasing in frequency before it dies away into a fading buzz.  They call from June to September.(see picture)
They lay their eggs at the base of trees and the emerging nymphs feed on the xylem of roots for 2-3 years before reaching adulthood.  Adults obtain sap from twigs and stems with their long beaks.  They molt several times, leaving their familiar dry paper-like husks on trees and buildings, a perfect mold of their last shape.  We used to see who could collect the most when I was a kid.  I know, my mother could never understand it either.
They have a large number of predators, the most impressive of which is the Eastern cicada killer.  This looks like a yellow jacket on steroids and you may see one emerging from its small hole in the ground to hunt its prey.  After paralyzing a cicada with its stinger, (see video) it laboriously hauls it back to the hole and lays eggs on the body.  Much like parasitic wasp eggs on a caterpillar, the larva feed on the paralyzed cicada, careful not to kill it until they are ready. The cicada killer won't attack us but may use its stinger for defense.  At 2 inches long, I don't think you will be tempted to pick one up anyway.**
Addendum:
An interesting time-lapse video on the cyclic 17 year cicada life cycle is at youtube.com.***
Tim Smith of MDC has posted Cicadas and Their Killers  on the MDC Fresh Afield blog
* Picture from Bugguide.net

**Picture from Texas A&M.
*** Sent by Hiltrud "Sam" Webber of Friends of the Garden.
Most information obtained from the MDC Poster, Singing Insects of Missouri.