Monday, February 20, 2017

Jumping Spider


Silk under the bark

This time of year it is hard to find new subjects in nature so I was pleased to find a new spider when out hiking with Mark Bower.  He found this when he stripped bark off a dead tree in search of fungi. "When I stripped off the bark, part of a web was wiggling, and I had to kind of squeeze the spider out." This species uses silk to cover its eggs and also to create a winter home for itself.

Metallic chelicerae of a Phidippus species
After chasing it around in a coffee cup with my camera, I gave up and cooled it in the fridge before finally getting good pictures.  The bright metallic blue- green chelicera are a sign of  the genus Phidippus.  It has the large anterior medial eyes typical of Salticidae.  This is the Canopy Jumping Spider, Phidippus otiosus, which can be found from North Carolina to Texas.  Females lay eggs in the winter, positioning a single egg sac under the bark of oak and pine trees.

Jumping spiders are favorites of collectors and you can even buy them online.  Their popularity is partially based on their eye placement, giving them a distinctive face.  Their large eyes seem to study their surroundings with apparent intelligence including to appear to focus on our faces when viewed closeup.*



The coloration of the spots on the dorsal abdomen of P. otiosus vary from white to red on available pictures.  In general, colors can vary a lot between individuals but the pattern of spots on the back of the abdomen is a common feature.*  Many of the Phidippus species have sophisticated hunting strategies.
"Like most spiders, jumping spiders have 8 eyes arranged in a characteristic pattern with two large anterior medial eyes in the center.  Extensive studies in the 1960s described the eyes in detail.
Jumping spiders, also known as salticids, alternate between entertaining and alarming us by planning prey-capture tactics ahead of time, adjusting their hunting behavior in accordance with how the prey responds and giving us other examples of un-spider-like acumen.  (Harland and Jackson, 2004).
Underlying salticid behavior, there is a more basic defiance of common sense. We may think that spider-size eyes are simply not suitable for seeing a lot of detail, but salticids seem to be telling us to think again. Here we have a celebrated example of how seeing with high spatial acuity can be achieved at a high level by a lowly animal working under severe size constraints. " Jackson and Harland.
* Common Spiders of North America, Richard Bradley, 2013

Thursday, February 16, 2017

Another Wasp in the House

Yellow banding on abdomen helps identify P. fuscatus - REK
P. metricus
We have new boarders in our creek house as well as up at Bower's cabin.  This is Polistes fuscatus, the Northern Paper Wasp. After years of harboring dark red-brown Polistes metricus that occasionally come from nowhere to assert dominance with their stinger, we are hoping for a better relationship with P. fuscatus.  There are prettier pictures of it live but this one from Jan Bower is the way I like to handle them - dead. 


These are social wasps in a matriarchy with a solitary queen although her "court" sometimes has other female queens that serve her.  Occasionally they will share their paper nest with P. metricus.  When they first emerge there may be fighting between the females until one establishes dominance.  This is a battle of reproductive strength where the dominant queen usually has the largest and most developed ovaries.

There is evidence that the wasps can recognize individual nest mates by their appearance.  When an individual was painted with black and yellow paint to change its features, it was greeted with aggression which let up with time, unlike a wasp from another nest, suggesting that chemical clues are more important in nest mate recognition.


There is extensive information on every stage of P. metricus life here.  This was the species that was studied in understanding frass-flinging caterpillars.   Caterpillars of silver-spotted skippers (Epargyreus clarus) were paired with P. metricus to determine the benefits of "flinging" frass (caterpillar poop) shooting it away from their leaf shelters.  We have a video of the frass flying out here, a fun sight before delving into the scientific experiments.  I will try to keep in mind the wasps' contributions to entomological research the next time I find them inside our bedroom window.

Wednesday, February 8, 2017

Bear Den study


This is the time of year when the MDC bear biologists are checking collared female bears in their dens.  This is an opportunity to count and study any newborn bears and the health of the adult.  I had the opportunity to tag along with Jeff Beringer and his crew to locate a bear den last winter.  We were in the northern portion of the known bear range in Missouri.

The Moment of Truth - taken with a telephoto, I'm not stupid!
They knew the approximate GPS location and used a hand held antennae to localize it in the woods.  This bear was nestled in the base of a hollow tree, but sadly did not have any cubs.  Jeff crept up to estimate the size and then measure the dose of sedative.  He sedated the bear using a jab stick, a 5 foot long aluminum tube with a spring-loaded hypodermic needle on the end.  After waiting for the sedative to take hold, there came a "moment of truth" when he had to creep up and test the bear.


Measuring the den

Then they pulled the bear out and started taking detailed measurements of everything including the temperature and dimensions of the den.  The bear was weighed by moving it onto a sling with a scale attached and lifting it up with a pole.  Over 20 measurements of the bear were recorded on the sheets you can see in this folder.  Fine details included a dental exam and even measuring the size of the nipples.  Body fat, hydration and muscle mass were measured by an instrument with alligator clips attached to the bear's lip and anus, (which I considered another way of testing the level of sedation.)
"Say Awww!  Dental exam- notice the broken left lower canine - REK
You can see the tracks of all radio collared bears that have been recorded at this MDC link.  The latest locations aren't posted for the safety and privacy of our bear neighbors.  You can see the locations of this bear (1519) by entering the number in the "bear selector" box on the left.  Turning on "Paths" and "Markers" will show where she traveled on individual days.

More photos and detailed narrative of this bear den check are on Flickr at this link.

Monday, February 6, 2017

The Unicorn

Unicorn antler, draped in velvet - August 2016

Unicorn and friend - September 2016
Early this fall our friend Willie started seeing a "unicorn deer" on game cameras along the creek.  It became an obsession like Captain Ahab's chase of Moby Dick.  When he finally got a shot at it, the arrow deflected off a branch and it bolted away, leaving a trace of blood.  He spent days searching for it without success.

Fast forward to this January.  He was out again the last day of archery season with a tag left when he saw an antler-less deer approaching.  It was underweight and limping badly, unlikely to survive long.  He decided to take it as his last tag in an act of merciful euthanasia.  It turned out to be a buck that had shed its rack early.  Cleaning it he saw the leg wound in its knee, then noticed the pedicle scars where the horns had shed.  The right pedicle was large and irregular, suggesting that this was the "unicorn."
Pointing out the "unicorn" point
Pedicle and antler - perfect fit - Click to enlarge

A week later, Barb found a shed up on the glade.  We sent the photograph to Willie who excitedly reported that it was the unicorn antler.  He retrieved the skull which showed a perfect fit between the antler and the pedicle.

Barb started reading up on deer antler growth and said deer and other cervids such as moose and elk were the only mammals that could regenerate a lost organ.  I argued that an antler isn't an organ but was destroyed by her her resources.  (After 51 years of marriage I should have known better.)

Antlers contain skin, bone, cartilage, blood vessels and nerves while growing.  They are the fastest growing tissue in mammals and can grow an inch a day!  The skin (velvet) falls off on its own although helped along by rubbing.  I had heard theories that it itched but apparently only deer hunters have the itch as velvet has no nerves by the time it falls off.

Deformities can cause atypical racks and are prized by deer hunters.  They are caused by injury to the pedicle or to the tender velvet that is providing nutrition to the underlying developing bone.  Even a leg injury can cause alteration of growth to the antler on the opposite side.


Just when I thought I had read everything to know about "unicorn" antlers, Zoe, a WOLF school student, taught me one more fact.  Did you know that the national animal of Scotland is the unicorn?  Historian Elyse Waters recently described the source of this connection.  Folklore extending back 5,000 year to the Babylonians held that unicorns were bitter enemies with lions and elephants.  It was a symbol of nobility, purity and power, still believed in when King Robert adopted it as the Scottish national animal in the 1300s, putting it on his coat of arms.
https://talesofmidlothian.wordpress.com/tag/unicorn/

One last technical note.  A unicorn would likely have had a horn made of keratin (if it indeed existed) and our deer's antler is made of bone.

Addendum:  I was showing the shed to Jay Barber and VP Shelly Jones and I mentioned that I had found a pair of sheds 20 feet apart and wondered if the deer might shake it head to get the second antler off once it felt the lopsided pressure.  She showed me this video of a moose shaking off a loose antler.

A little Googling brought some confirmation of this.  Several sites talk about deer sheding their remaining antler by shaking or rubbing them, as in this note from Havalon.com:
"Antlers occasionally fall off together, but that’s somewhat rare. I do believe; however, that a mature buck will put quite a bit of effort into getting the other side off because of the lopsided feeling he has with one antler. He shake’s his head, rub the antler on trees and push it on the ground to work it off. If you find a nice shed, put an exhaustive effort into finding the other side. Chances are good that it’s close by."

Friday, February 3, 2017

Cedars Invade the Praries


Eastern red cedars, correctly a juniper, Juniperus virginiana, have spread astronomically over the last century.  Schoolcraft only listed them twice during his 3 month trip through the Ozarks in 1818.  Fire suppressed them until we began controlling wild fires the last 100 years.  A cluster of cedars gives robins food (cedar berries) and protection from the wind in winter, a debt they pay back by perching on fence lines and balds, pooping the seeds randomly.  Cedars cover the fields and glades, and our Ozark bald landmarks have become hirsute.

A story in Kansasagland.com highlighted the struggle of Kansas cattlemen to maintain their prairies for grazing.  Groups are coming together to create prescribed fire associations because cedars are killed by fire which will spread rapidly through a field.  The Anderson Creek wildfire last March has been called an "ecological cleansing," clearing cedars in 574 square miles of Kansas and Oklahoma.  It would have cost $56 million to achieve with standard removal practices of land clearing and cedar mulch production. This however was at the cost of destroyed homes and fences and the death of livestock.
Cedar cut for glade restoration, 1998  - REK
Texas has a similar problem with Ashe Juniper invasion that is nothing to sneeze at.  In addition to "cedar fever," the allergies that lay Texans low in the winter as the junipers begin mating, they are contributing to the water shortage and fire risk.  A mature tree sucks up 33 gallons of water a day, robbing needed soil moisture as well as ground water. After the Anderson Creek fire, ranchers reported “We’ve got water in streams that haven’t run for years because the fire decimated so many cedars.”


Even our humble efforts of clearing cedars and burning for glade restoration on our land are a lot of work and expense.  The cost of clearing these grass lands is great but the cost of fire risk and the loss of prairie lands is even greater.

Read more here: http://www.kansas.com/news/local/article105463466.html#storylink=cpy


Wednesday, February 1, 2017

Winter Oyster


Hiking the woods on a dreary winter day, exciting finds are rare but I hit the jackpot with these beauties.  They were in clusters on the lower eight feet of a shagbark hickory as well as a group on an exposed root covered with dead leaves.  These are winter oyster mushrooms, Pleurotus ostreatus as Mark Bower reminded me.  These fresh specimens have a rich glistening brown top, darker than their more common summer cousins, the pale Pleurotus pulmonarius.  

Gills run all the way down the stalk
Prying up the bark
Both species grow shelf-like, initially somewhat firm but never hard like the brackett fungi.  A distinctive feature of Pleurotus species are the whitish gills that run down the stem to where they join the log.  These fresh specimens were firm enough that they were actually pushing up the slabs of bark.

Pleurotus species are saprobic, meaning that they live on dead or dying wood, eventually producing a white rot.  The front half of the tree was riddled with damage from a very determined pileated woodpecker, exposing the rot.
Crazy P. pulmonarius log

For several years we had a mother lode of P. pulmonarius on two long downed logs.  There was even one day that Barb said "Don't bring in any more oysters!" but then she relented.  Oysters are one of our favorite mushrooms, versatile in the kitchen as a substitute in Oysters Rockefeller,  mixed in scrambled eggs or simply cooked in a little butter. (OK, sometimes a lot of butter.)

Speaking of butter, these mushrooms eat decaying logs but they aren't vegan.  They need a little nitrogen to grow and they get it by becoming a predator.  Like Audrey in Little Shop of Horrors, they can eat meat!  Well, that is if you consider nematodes meat.  Rachael Sargent describes the process.

Pleurotus attacking a nematode- photograph by Greg Thorn
"First, the oyster mushroom fungus plays a trick to attract nearby nematodes: it exudes chemicals that smell like dinner. Once a hungry nematode ventures close enough, the fungus uses a weapon called a “sticky nob,” which Thorn described as looking like a tiny lollypop. These nobs stick out like spines from the fungus' hyphae. In some carnivorous mushrooms, the ball of the lollypop has a glue that is especially sticky to nematode skin, but the oyster mushroom uses a different strategy. Its “sticky nobs” aren't sticky; instead, they have a toxin that paralyzes nematodes.

Once the nematode is immobilized, the fungus can harvest the victim’s nitrogen by sending hyphae through its body. Thorn described the moment of capture: “Watching through the microscope, you can see the nematode make one last pathetic attempt to wriggle away.”

We aren't the only species that eats oysters.  There was one batch chewed down to a nubbin, possibly by a squirrel.  There are at least 136 taxa of beetles that eat them, 60% of which are obligate mycetobionts (must live in fungi some time in their life cycle).  Note to self: Inspect the gills carefully.

Never eat any mushroom that hasn't been identified by an expert.  The next time you eat a oyster mushroom, just remember to look for the beetles and think of the tiny worms that were digested by the mushroom.  If that thought bothers you, contact me and we will take the oysters off your hands.

Wednesday, January 25, 2017

Foam on the Water


Following several days of modest rain there was water once again flowing down the hollows into Bull Creek.  These are ephemeral streams, flowing only after a rain, then holding pockets of water for weeks until they gradually dry out.  Foam appearing in pockets of turbulence always raises the fear of pollution.  So what else could cause foam?

Actually foam like this is a natural phenomenon.  Like the suds in a bath tub, it is caused by a surfactant that lowers the surface tension of water.  Soap is a surfactant made from oil and lye (sodium hydroxide).  This creates a molecule that is water soluble on one end and not on the other,  creating a thin layer of lipids on the surface.  Think of the solution that kids blow bubbles with.

In nature there are natural surfactants called DOC (dissolved organic carbons).  These are formed by the decomposition of algae, aquatic plants, dead leaves and animals that produce oil in the form of simple fats.  As they break down over time they produce fatty acids that are lighter than water and won't mix but lay on top in a thin layer.  In quiet waters this can appear to be a thin layer of oil.  Turbulent water flow mixes air in and viola!...bubbles.

Foam at the falls on Bull Creek
There is frequently a collection of bubbles in an eddy below a little water fall at our swimming hole.  Occasionally this collection will be quite large and can collect little particles on top.   Some biologists use this as a means of looking for exuvia (molted insect skin), aquatic fungi, moss spores, etc.

Of course, foam can also come from pollution so if in doubt, it pays to check.  More details are here.

Good Read:
Insect brains- bigger than you think