Nature Blog Network

Thursday, November 20, 2014

December Phenology 2014

Phenology - the scientific study of periodic biological phenomena

By now the male black bears will be denning up, usually a few weeks after the females.  Black bear cubs are born this month but you will never know it.  They are curled up in dens and the mothers will be sleeping through much of their nursing.  Human mothers, eat your hearts out!  The cubs won't make their debut for another few months.




Red squirrel drey
When winter weather is cold and wet with icy winds, squirrels will gather in their leafy dreys nestled high in tree forks; this is to conserve energy. Yet late December brings mating season when males can be seen chasing females, as well as chasing off other suitors. This ritual of chasing, occurs through the trees at top speed, performing some of the most breathtaking acrobatics imaginable.
 

Christmas fern is the largest of the evergreen ferns in our region.  Snow may flatten its fronds to the ground, but once the snow melts, the Christmas fern will reappear in all its green glory.


Barred Owl
- Wikimedia
Barred owls call "Who - Who cooks for you - who cooks for you all?"  Courtship begins in early December and although owls are more elusive to see at this time, their courtship “hoots” can be heard.  Two to four eggs will be laid in hollow trees or hawk nests in February or March.

Great Horned Owl - Greg Hume

Great horned owls' courtship "hoots" can also be heard beginning in early December.  Less common than the barred owls, you may want to refresh your memory of their calls.  Listen to this "Hoo  Hoo-hoo    Hoo-hoo." After mating they will adopt an unused hawk or eagle nest and lay one to six eggs in January or February.



Shelf or bracket fungi that grows on trees, stumps and fallen logs are very much part of the winter scene as they are very obvious and attractive when the foliage is off deciduous plants.  Look for the various colors of tan, brown, pink and rust found on the top surfaces.
White crowned sparrow- Wikipedia
Dark-eyed junco - MDC

Don't forget to stock up on bird food.  Winter is when the insects and fruits get scarce and nutrition is important for overwintering species.  All the usual suspects will show up at the feeder but be on the lookout for some winter species.  Dark-eyed juncos return, not dramatic in color but they make it up in "cuteness." You might also spot a white throated sparrow, visiting for a Christmas vacation.  They breed in Canada and come to "snowbird" in Missouri.

Bats Jamming for Food

Mexican free-tailed bat - Wikimedia
In a previous blog we discussed how tiger moths elude bats by jamming their sonar. Bats have poor eyesight and hunt by echo location, sending out high pitched sounds that bounce off objects.  They can judge the size and speed of prey with this.  Tiger moths can produce a series of high speed clicks that confuse the bats.  "Since the attack sequence of a bat lasts less than a second, the moths have to react fast.  Fortunately, the moths can produce up to 450 clicks in one-tenth of a second."*

While studying this phenomenon, this same team of scientists discovered that bats can jam the signals of other bats competing for their prey.  A story from  Livescience.com reports that William Conner, a biologist at Wake Forest University, discovered a strange sound that Mexican free-tailed bats made only when another bat was homing in on a moth they were competing for.
"Competition for food can be fierce, and Mexican free-tailed bats emit a special call that can interfere with the sonar of other bats that are pursuing a meal. "They get into amazing aerial dogfights," said study leader William Conner, a biologist at Wake Forest University in Winston-Salem, North Carolina. "One will jam the other, and the other will jam back."
The bats would produce a "terminal buzz" just as they were about to capture their prey.  When the researchers played the interference sound, the bat was 86% more like to miss the prey.  Do other animal species use similar tricks?  Stay tuned for further research.


Other news from the bat world highlights the danger of wind turbines to bats.  They are apparently drawn to them by confusing them with very tall trees.  Birds face their greatest danger when the blades are turning at high speeds.  Although they look slow as we drive by them, the tips of the blades reach between 138 to 220 mph.  Bats are attracted when they are moving slowly, apparently avoiding the high speeds which create greater air turbulence.  Details at this link.

* More on moth jamming bats at Discovermagazine.com. 

Monday, November 17, 2014

Acorn Weevil


This August I found this long-nosed beetle in a patch of oak trees.  Although it looks dangerous with a snout almost as long as its body, you should "fear no weevil," for it attacks only plants.  With its long slender beak and its sharply elbowed antennae, it is identified as a nut and acorn weevil, a member of the genus Curculio with over 30 species on our continent.  Many of these make their living on oaks.

Curilio female weevil.  Females have the longer beak
Last week we traveled to Taneyville to make nature mobiles with the 5th grade class.  The class had collected a variety of nature finds for elements on the mobiles including bags of acorns.  At the end of the session, John Shelton came up to me and generously offered me part of his collection of acorns to use for another class.  I sealed them in a ziplock bag and 24 hours later I found a Curculio larva in the bottom of the bag adjacent to a newly drilled acorn.

Once out of the bag, it laid still for a minute and then started to make its getaway, looking for some nice soil to pupate in for a couple of years.  It was slow moving so I had lots of time to set up for this macro movie to document its progress.

Inserting the egg - USFS

Life begins for a weevil when a female bores into a green developing acorn and deposits a single egg.  She seals up the tiny hole with her fecal material and the larva will emerge from the egg to find shelter and sustenance.  After consuming most of the nut's contents, it carves out a round hole and struggles out of the acorn.  The larva will then crawl off into the soil to pupate.

The pupa may not emerge for over a year, coming out as an adult in the summer, hopefully at the time the acorns are greening up.  After mating, the female begins a long climb up a mature oak to start the cycle again.

Larva in acorn - USFS
The whole process is shown in this short National Geographic video.









Friday, November 14, 2014

Harvestman Mating


Gala Solari Keller sent me this picture of two harvestmen head to head, asking if this was predatory or mating.  A "female harvestman" is a bit of an oxymoron, as would be calling her "daddy longlegs" or "granddaddy longlegs."  For that reason I will refer to them by their order name, Opiliones.  Not only are there female "daddies," some species' females can reproduce by parthenogenesis without male fertilization.  Take that, you sexist naturalists!

Opilione - note combined cephalothorax and abdomen into a single body segment.- Wikimedia
Brown recluse body-
Separate cephalothorax and abdomen
Opiliones (pronounced O-pill-e-on-es )are frequently confused with spiders which are in a separate order, the Araneae.  There are two key characteristics which separate the orders.  Opiliones are easily distinguished by a single globular body segment, unlike the spiders which have their abdomen separated from their cephalothorax by a constriction.  They also have a single pair of eyes versus 3 to 4 pairs in spiders, a distinction almost impossible to make on a living specimen as most of their bodies are tiny, typically less than a quarter of an inch.

There is a common misconception, perpetuated in some web sites, that Opiliones can bite humans or that their venom is more toxic than that of a spider.  They actually don't have venom glands or even suck their food as liquids like a spider does.  They actually take in small pieces of insects, plant material, fungus, or even dung.  These are stalkers, not trappers- they don't make webs and don't even have silk glands.

As slow moving creatures they are vulnerable but have several interesting defenses.  They have scent glands which disuade predators such as ants and even birds.  They may bob up and down when disturbed.  They also will sacrifice a leg (after all they have 8), a practice called autotomy.  Because there is a separate pacemaker in the femur, the leg can twitch for a prolonged period, much like the tail of a skink, distracting the predator while the victim sneaks away. 

A predator is not the only cause of the loss of legs.  This video shows the perils of sex in Opiliones.  Males may fight over the female's charms and use their jaws to amputate a rivals legs.  Notice at each attempted mating the pair are face to face.

Mating - note the red mites, a common problem among Opiloines
The closeup of Gala's original photograph above shows the smaller male, on the left, head to head with the female.  A few mites don't seem to be slowing them up.  Mites are a common problem for them, usually one or two per customer.  The one I photographed on Bull Creek had a major infestation and was moving slowly, not attempting to escape from my camera.  These Erythraeidae mites have larvae which parasitize Opiliones, sucking fluid from their legs.

Now back to the original question - dinner or sex?  It turns out that Opiliones mate face to face as seen in this video and lots of pictures including Gala's.  The male has a penis and mates by direct copulation.  This research paper has more details on the anatomy describing how this occurs and may be more than you  want to know.  The important thing is that they know it.

Finally, Opiliones are frequently gregarious, gathering in large masses.  This video is not for the reader with arachnophobia.


Concise information about harvestmen (and women) is at  David Darling's Encyclopedia of Science.

Wednesday, November 12, 2014

Small World

Jumping spider eyes (20x) - Third Place, Noah Fram-Schwartz
As the cold weather settles in, it is a good time to sort through favorite nature pictures.  I was reminded of this by seeing the winning entries in the Nikon Small World 2014 contest.  My personal favorite is the jumping spider eyes at 20x above.  You can see all of the winning entries at the Nikon slideshow site, using your right arrow key to thumb through the pictures.

Each year the MDC Nature Calendar contest brings out the competitive urges among our members (Jay is a perennial favorite), and several of their pictures have been selected.  I suspect that many of you have favorite pictures hidden away on your computer.

Most of us carries a camera around daily that has more capability for high quality photography than was available 20 years ago in high end equipment.  The digital era and the cell phone has made photographers out of all of us.
Larva crawling out of a grey headed coneflower seed head after the seeds were removed.
Here is a challenge to our Springfield Plateau MN members.  Email me your favorite nature pictures for a future show of Best Shots.  You can pick them for beauty, unusual subject or just an interesting discovery you made as above.  We will all be winners. 

Monday, November 10, 2014

Slime Mold Beauty

Mark Bower shared this set of pictures from one of his early morning forays. It really begins with the photograph below.  The story is in his words.

Physarum polycephalum on a tree trunk -  all pictures from Mark Bower
Close-up of the "heads"
"This is Physarum polycephalum, the "Many-headed Slime", or the "Grape Cluster Slime". This is the plasmodial phase after the single celled organisms have "decided" to coalesce into a creepy yellow mass with bulbous areas (these are the "heads"). These pictures were taken at Valley Water Mill. The second picture (on the right) is a close-up of the "heads"."
Notice the faint streak of yellow in the green bark furrow
"The next day, I excitedly went back to the tree for some better pictures and I thought it was gone (light was dim). I thought the darned thing had slinked away. After scouring the area around the tree (20 yard radius, I gave up on finding it. However, when I went back to the tree, the light was better and it appeared that it was still there, but had changed color to a greenish hue, (see above) and it had developed the grape-like spore stalks."(see below)
  Note that most had turned dark green, now with grape-like spore stalks
"I collected some of these green spore clusters and took them home. After arriving home about 1 1/2 hours later, the green clusters had already turned yellowish. The next day, they broke open and released the brown spores."
Green clusters had already turned toward yellow
Next day - Broken open and releasing spores
Mark's notes led me into a maze of reading on myxomycetes* and P. polycephalumIt is usually found in shady, cool, moist areas, such as logs like Mark's as well as decaying leaves. It seems to sense light causing several reactions.  While light can trigger spore growth it also can repel the slime mold.  Since it is easy to grow and has interesting growth patterns, it has become a favorite "lab rat" for myxomycologists.

Yes there are myxomycologists, and we will all have a chance to meet one who literally"wrote the book" on slime molds.  Dr. Steve Stephenson is a Research Professor in the Department of Biological Sciences at the University of Arkansas.  He wrote Myxomycetes: A Handbook of Slime Molds as well as many other books and papers on related fields.  He will be at the Springfield Conservation Nature Center on Friday, November 21 at 7:00 PM discussing "Myxomycetes- Slime Molds in Nature."  This is a great opportunity to hear more fascinating details from the expert.

P. polycephalum is not just another pretty face.  Although a single celled organism, it seems to be able as a mass to make decisions that our congress might envy.  More on that in a future blog.

The Kingdom Fungi, Steven Stephenson, Timber Press, 2010.

Friday, November 7, 2014

Sycamore Assassin Bug



I have been seeing the creature above around our creek house the last few weeks.  Although it is only 1/2 inch long, I can now recognize it by the distinctive color and slow direct flight, usually only going a few feet before landing.  The distinctive shape and snout is typical of an assassin bug.


Searching Bugguide.net for 'assassin bugs' I paged through the images until I found one with the distinctive banded legs.  This was in the genus Pselliopus, and the 'info' site gave a key to the species.  Clicking on the choices, up jumped pictures of Pselliopus barberi species, a perfect match.  (It isn't always this easy but that is the fun.)  The 'info' page says the Pselliopus comes from the Greek psellion 'anklet/bracelet' + pous 'foot', a reference to the banded legs.

Orange Assassin Bug with Tobacco Horn Worm - Pselliopus barberi
Sucking juices of a tobacco horn worm - James VanCleave
Once you have identified a genus and even species, you can click on 'images' and find pictures of the larva and sometimes even the eggs.  There usually are some high quality pictures of the insects (or arachnids) eating, procreating, or just hanging out like these here.  Many of the contributors are generous enough to share their pictures.  The 'info' button will usually bring up details on range, habitat, size, season and life cycle.

Mating P. barberi - Matthew Roth
Bugguide.net is a great resource to identify insects and arachnids and learn about your finds.  If you can't find a match, join (free) and send in pictures.  You will usually get information from their many knowledgeable volunteers within a few days.  At times it will be referred to an expert specializing in hard to identify species who will later respond with difficult species identification or pointers.

Just looking good!   Shelly Cox of MoBugs
Finally, by searching using the genus and species rather than the common name you are more likely to find detailed information from reputable sources.  Also called a sycamore assassin bug, it is usually found on flower heads in the summer until it migrates to tree bark and sometimes houses to overwinter.  I came up with more details on our P. barberi on this Americaninsects.net link.  Now wasn't that easy?


What is this which is coming next week to the blog?