Rock Snot

Didymo - MDC

David Casaletto just beat me to the punch in posting an excellent article on Rock Snot, aka Didymo in Ozarks Water Watch.  As a native Kansan, I want you to know that "Rock Snot"has nothing to do with the KU "Rock Chalk - Jay Hawk - KU" cheer.  When I was in the 5th grade, there was a saying like "I thought that it was mucus but its not" (say it fast) that we thought was a really funny risque joke.  Unfortunately, rock snot is no joke if you are a critter living in a stream.

Rock snot is also called Didymo, short for Didymosphenia geminata. It is an algae whose infamy comes from its ability to rapidly proliferate and cover the bottoms of streams in dense mats, choking out the normal macroinvertebrates which are important links in the food chain for the fish we love to catch. In addition, it forms dense slimy sheets which cling to waders and fishing lines, eventually making fishing and swimming unpleasant or even impossible.

"Didymosphenia geminata is a diatom, which is a type of single-celled algae unique for their silica (SiO2) cell walls. The life history of diatoms includes both vegetative and sexual reproduction, though the sexual stage is not yet documented in this species.
The stalk can attach to rocks, plants, or other submerged surfaces. When the diatom cell divides, through vegetative reproduction, the stalk divides too, eventually forming a mass of branching stalks. The nuisance build-up is not the cell itself, but their massive production of extracellular stalks." *

While invasive species are frequently defined as non-natives or exotics (i.e. brought in from other regions), Didymo is a native to the Northern Hemispheres of both Asia, Europe and America. Over the last 20 years it has been proliferating in its native range as well as slowly expanding into other waters. It first appeared in New Zealand in 2004 and its spread there is documented in Wikipedia.

Once in the water, it is impossible to eliminate.  Prevention is focused on preventing the spread of the moist diatoms from one watershed to another.  Felt soled waders and moist boats and containers are the mechanism of spread and the article defines steps to avoid spreading the algae.  The steps of Check - Clean - Dry are outlined in today's News-Leader article on Didymo.

At last Rock Snot is getting the disrespect it deserves.

* The science of Didymo is in this Wikipedia article.

Tooting our MN Horn

The 2010 Annual Report of the Missouri Master Naturalists is out * and the results are impressive.

• During 2010, 180 new volunteers participated in training that was conducted by 8 Chapters
• Through December 2010, with combined efforts of 11 recognized Chapters, 981 volunteers have been trained as Missouri Master Naturalists;
• Approximately 8,400 hours of advanced training and continuing education were obtained by Master Naturalist volunteers;
• A total of 524 volunteers have become Certified Missouri Master Naturalists;
• During 2010, volunteers provided 36,410 hours of community volunteer service
• Over 110, 000 hours of volunteer service have been provided to local communities since 2004;
• Approximately 150 organizations have partnered with Master Naturalist chapters at the local level to accomplish natural resource education efforts and service projects within the community
• The economic impact of Missouri Master Naturalist volunteer service during 2010 is valued at $850,247.001
• The cumulative economic impact resulting from volunteer service provided by the Missouri Master Naturalist Program is valued at $2,531,129 **

Give yourselves a big round of applause with your hands, your paws,  your fins or "anything you got."

*  For the full 25 page report, email me with"Report" in the title.

** The value of volunteer service calculated using Independent Sector’s $20.85 per hour for 2010.  The hourly value is based on the average hourly earnings for private nonagricultural workers as determined by the U.S. Bureau of Labor Statistics.  This figure is then increased by 12 percent to estimate fringe benefits.  http://www.independentsector.org. The cumulative economic impact results from the value of volunteer service during the years of  2004-2010.

Ambrosia Beetle- Part II

The Ambrosia Beetles (Xylosandrus crassiusculus) that we discussed  in last week's blog is only a tenth of an inch long.  Unlike the beetles causing Thousand Cankers which bore just under the bark, the Ambrosia Beetle bores tiny tunnels deep into the wood and carries a fungus which eats into the xylem.  The beetle and its larvae then eat the fungal mycelium and clusters of its spores, their only source of food.   The relationship is symbiotic in that the fungus is totally dependent on the beetle to spread its spores and reproduce.

How does the fungus make the trip?  It travels in the beetle's mycangium, specialized structures for the transport of symbiotic fungus.  Many beetles with this feeding strategy can eat other things or even digest wood along with their fungal meal.  Some types of beetle mycangium are simple pits on the surface of their body where the fungi hangs on seemingly by chance.  Since the Ambrosia beetle won't survive without its fungal friend, it goes to greater lengths to make sure it survives the trip.

Ambrosia Beetle's mycangium have deep and complicated pouches.  They may have glands which secrete substances to support and feed the fungus.  Some even have fine setae (hairs) to scrape the fungal spores and mycelia from the tunnel walls into the pouch.

The spring and summer flights of the beetle can be monitored by the use of traps.*  The bait is ethanol which is normally extruded in tiny amounts by sick or dying trees.  The Ambrosia beetles are lured in to have a drink at their equivalent of the neighborhood bar and succumb to the soapy water at the bottom.   You might say that they get "really bagged".

*  More on traps at this site.
The Ambrosia Beetles article has detailed information about this creature.

Ambrosia Beetle- Part I

Gallery, larvae, and an adult beetle Wikipedia

I just came across an interesting article in the Missouri Environment & Garden Newsletter.*  In it, Christopher Starbuck, Associate Professor of Plant Sciences at Missouri University describes another doggone invasive species, this one with wings, legs and a bad case of fungus.

The Granulate Ambrosia Beetle (Xylosandrus crassiusculus) hitched a ride to South Carolina from Asia in the 1970's on packing crates.  It has gradually spread across the Gulf States and has now been found in Missouri on the MU campus. It seems to prefer ornamental trees such as dogwoods and fruit trees, but can be found on some oaks and walnuts. There are 30 plus Ambrosia Beetles found in the US but this Asian visitor is more successful than the others and can kill trees when present in numbers.

The diagnosis is made by finding tiny white "toothpicks" extending out from the bark (see picture). These are columns of frass (insect poop) extruded when the beetle is boring its tunnel. This is just debris as the beetle doesn't digest wood for nutrition.   Its sole food is the Ambrosia fungus that the female transfers into the tunnels.

There are several dozen species of Ambrosia fungi, all of which are only found in tunnels created by the Ambrosia beetle.  Their relationship is pure symbiosis, each dependent on the other for survival.

According to Wikipedia there are around 3000 beetle species in many different families which use this same fungus feeding strategy.  Many are not related and have developed this adaptation independently, an example of convergent evolution.

When the Ambrosia beetle larvae become adults, their next challenge is to go find a tree of its own.  The problem is how do you pack your lunch when you only eat a fungus growing in a tree that you mother planted it in?  The answer will be in Ambrosia Beetle- Part II, the next post.

* Dr. Starbuck's article is available at this site.  Select Volume 17 No.2 and click on "Granulate Ambrosia Beetle: Another Exotic Pest of Ornamentals to Watch For" to download the PDF.

Red Shouldered Hawk

Bob and Ruby Ball are genetically programed birders in addition to his professional photography.  They shared this story about their backyard hawk sighting.

RS Hawk with Mole (Bob Ball)

"We returned home after a birding outing yesterday and found no birds in our backyard.  Ruby quickly discovered a large hawk, which we first thought was a Coopers.  A few birds gradually began to move back into the yard.

We couldn't understand why the hawk didn't attack.  Suddenly, it flew to the ground and came up on our back fence with a MOLE in it's talons.  I can't begin to describe Ruby's jubilation!  She has been working on getting rid of those moles for several years and hasn't found a good solution.  She's hoping the Red-shouldered Hawk will come back soon.  It is a life bird for our back yard list."

While uncommon on the open plains to the north and west, we see Red-shouldered Hawks commonly along Bull Creek.  They prefer wooded streams and rivers, leaving the open fields and prairies to their commonly seen Red-tailed cousins.  Their "Red shoulders" are very hard to see while their banded tail is prominent in flight.  (See picture)

They have a distinctive call, repeating "Ker-yah" insistently at two to three second intervals as they circle in the sky (hear it here).  The Blue Jay has learned to mimic this call, scaring birds off their nest so it can fly in and feast on the abandoned eggs.

Red-shouldered hawk nest

You are more likely to see the Red-shouldered flush from a tree limb perch in the forest.  Their distribution follows their prefered habitat, extending from Missouri on to the East as well as along the West Coast, avoiding the Great Plains.

They either hunt from a perch or circle high in the sky, then folding their wings back to rocket to earth, spreading their wings at the last second as they nail their prey with their claws, a behavior called "stooping".

Red-shouldered Hawks are known to over-winter in the Ozarks along our streams.  Several years ago we had a pair build a nest along Red Bridge Road where we could monitor it all spring until the little fuzzy headed chicks finally fletched.  They hung out in our woods all summer like teenagers with a Nintendo before finally taking off to get their own apartments.

Red-shouldered chicks

Ruby's hawk perched on a low fence was both unusual and a highly successful strategy for a mole feast.  I am planning on building a perch in our mole infested front yard to recruit her hawk - sorry Ruby.

More at Wikipedia.

Spring is Humming

We are preparing for an attack on our natural resources at Bull Creek.  A highly mobile force will soon be attacking our deck, fighting among themselves as they suck up our carbohydrate resources.  I am speaking of the pending Attack of the Ruby-Throated Hummingbirds.  While there are occasionally other varieties such as Anna's and Rufous, most of us will see only the Ruby-Throats. 

You can follow the invasion on the maps at http://www.hummingbirds.net/map.html.  I have always assumed that the appearance is random but one scientific source says otherwise.  It is even possible that the hummingbird that left last fall (was it just a few months ago?) is the same one that you will see this year.

"Banding studies suggest that individual birds may follow a set route year after year, often arriving at the same feeder on the same day. We do not know if any individual bird follows the same route in both directions, and there are some indications that they do not."

These birds originated in the tropics but with the ending of the last Ice Age, they began to expand their summer range, now making the long trip north each spring.  They begin in Panama and Southern Mexico and migrate as individuals rather than flocks.  They fuel up on insects and spiders for high energy stores of fat - can you picture a fat hummingbird? 

"Some will skirt the Gulf of Mexico and follow the Texas coast north, while most apparently cross the Gulf, typically leaving at dusk for a nonstop flight of up to 500 miles, which takes 18-22 hours depending on the weather. Although hummingbirds may fly over water in company of mixed flocks of other bird species, they do not "hitchhike" on other birds. Some hummingbirds land on offshore oil rigs or fishing boats to rest."

There is more detailed information on the Ruby-Throated Hummingbird migration at http://www.hummingbirds.net/migration.html.

GOMOMS Forays

The Greater Ozarks Chapter of the Missouri Mycological Society has scheduled its first Mushroom Forays. 

• Valley Water Mill at 9:00 AM on April 10th.
•  Bull Mills on Bull Creek at May 8th at 9:30 AM.

Click here for Foray directions, either as a Doc file or a PDF.