Saturday, March 31, 2012

An Old Maple Seed Pod Is Still Spectacular

I've clowned around with a Maple seed "helicopter" stuck on my nose, have you?

Well, look who is wearing one now! 
Maple seedling with its seed's samara
This tiny maple tree seedling wears its old seed pod, or samara, (maple seed's helicopter) very well.
When I saw this maple seedling spotlighted by the spring sun's rays, I began to think all kinds of thoughts about spring.
Maple seedling with its old seed pod
   When I see signs of spring, I think about how the tilt of the earth on its axis causes the change of seasons. The change in orientation of the earth's axis changes the amount and angle of the sunlight reaching our part of the earth.  This changing photoperiodic stimuli, and other factors, "turn on"  the chemical signals that initiate germination in the long dormant seeds as well as the other new life that is springing forth.
 The maple seedling wearing its funny hat made me think of other things...
  • I thought about seed dispersal... how, last year, the samara fluttered here from the woods across the yard.
  • I also thought about the maple tree's pollination that happened last spring and very soon will happen again.
  • I also thought about photosynthesis and other processes that are happening in the little seedling.
   One of the processes happening in that seedling's leaves is the production of ATP.  Here is a link to a good animation of ATP synthase (basically a micro electric motor) in action.
 
   Now, this maple seedling may look like it is clowning around.... that "helicopter" may look a bit like a dunce cap... but, if you ask me, the seedling can wear its "hat" with a spectacular flair... and that is how to wear a samara!

Monday, March 19, 2012

Sallow the Maple Sap Thief

   This sallow moth, or wintermoth, showed up at a friend's maple sap bucket on February 28.
A winter flying moth feeding on maple sap
  This moth is from a family of amazing winter-flying moths which have the ability to fly at much colder temperatures than many other insects. These moths spend the winter as adults hiding in the leaf litter and emerge during milder days to feed on sap. The flying stage in their life-cycle is from late fall to early spring.  (I've previously posted about another sallow moth which I found flying in late November.)
  I called this moth a thief in the title, but come to think of it, this sallow was more like an opportunist than a thief since it was just availing itself of maple sap that leaked from around the maple taps. 
  I have asked myself, "How would the moth find its supply of sap to sip if people wouldn't tap maple trees?"  Well, one likely source of the moth's food supply is sap leaking from wind damaged branches and other naturally wounded trees.  I've also read that some squirrels nip notches along the top of branches.  In these notches sap will puddle... then squirrels can enjoy a sweet treat.  I expect the moths avail themselves of the squirrel's sweet spots as another source of sap.
A winter-flying moth - a sallow - enjoying maple sap
I happened to capture a few photos of the moth's proboscis.  What a spectacular "tongue"!
Sensilla on a moth proboscis - for tasting the sweet maple sap
 All those finger-like projections are called sensilla.  From what I read these function as taste buds.  Perhaps these sensilla also perform other sensory functions.  I wonder if they also help in the gathering of sap?
 I've been looking at the 90-degree bend in this moth's proboscis and it is obvious the proboscis is definitely more of a high-tech apparatus than a "straw".  I cropped the picture for a closer view of the bend/kink in the proboscis (see the photo below). 
   Winter-flying moths also have some other unique, high-tech design features.  I'm especially fascinated by the ones which allow the moths to function at much lower temperatures than many other insects. One of the moth's most obvious cold weather survival features is shivering... this warms them up for flight.  Another feature is the thoracic pile, or fur coat.  This "fur coat" (see the photo below) helps insulate the moth and helps it maintain its temperature above the surrounding air temperature.  The amazing moth has other heat distributing and thermoregulation features which are internal.
 I see this sallow moth's wings are worn... making its markings are barely visible.  That wear is evidence of the moth's habit of hiding out in the leaf litter all winter long. 
Wintermoth - a sallow moth - feeding on maple sap
 I like these moths with their unusual life-cycles and winter-flying abilities.
 That is one sweet moth!

Friday, March 9, 2012

Yellow-Spotted Salamander's Night At The Pool

   Wow! Last night was "Salamander night"!  

   Here in north-central Pennsylvania it was the first (this spring) warm, rainy night after a stretch of mild weather. Since that's what brings the Yellow-spotted Salamanders (Ambystoma maculatum) out of the woods seeking the vernal pools in order to mate, we went out "salamandering".  Yes, we found the salamanders in a frenzy of activity at the vernal pool.  The salamanders were also out in force crossing the roads as they migrated from the forested mountains down to the pools.
Yellow-spotted Salamander crossing a road
Yellow-spotted Salamander crossing a road
   Here in this photo I can see three of the Yellow -spotted Salamanders.  The boys are "measuring" one of them.  Another one is to the right near the youngest boy's foot.  The other salamander is way back in the brightest glare of the car's headlight reflection on the road.
Salamander night

   Yellow-spotted Salamanders weren't the only amphibians out crossing the roads during this rain storm.

 We saw many frogs and some other kinds of salamanders as well.  Oh, the carnage on the busy paved roads.  The squashed salamanders on the dirt road was bad enough.
 Anyway, here is a picture of a Yellow-spotted Salamander.
Yellow-spotted Salamander - Ambystoma maculatum
Yellow-spotted Salamander - Ambystoma maculatum
   Aren't they cute?  The rows of yellow spots contrast nicely with the salamander's black body.  These salamander grow fairly large... many of the ones we saw probably measured about 7 inches long.
   All this road crossing and crawling about is for the purpose of getting the salamander's eggs fertilized and deposited in the temporary pools. The benefit of having their larvae hatch in a temporary pool, is because the pools will dry up in the summer = no fish and therefore less predators.

The next photos show some of the incredible gathering of Yellow-spotted salamanders in the vernal pool.

A group of these salamanders is called a congress. What a sight!
Yellow-spotted Salamander mating congress in a vernal pool
Yellow-spotted Salamander - Ambystoma maculatum - mating in a vernal pool
   Last night, when I took these pictures, there were, perhaps, a hundred spotted salamanders in this small vernal pool.  Tonight I looked again at the vernal pool.... not one salamander was visible.  Last night really was "Salamander Night".
  Soon the salamander egg masses will show up in the pool.  In the photo below, a female salamander is plump with eggs.
A female Yellow-spotted Salamander - Ambystoma maculatum
Here is a photo of a mass of Yellow-spotted Salamander eggs.  Unbelievable, eh?
Yellow-spotted Salamander eggs
How does the salamander lay all those eggs?  ...see my post on salamander egg masses.

These spotted salamanders are really cool-looking.  Even more amazing are the salamander's larvae as they gaze out of their green eggs...they have truly "gone green"... see my post from last spring about the
Salamander's green egg
solar powered salamander eggs and my other post about the eggs' algal symbiont, Oophila amblystomatis.
Yellow-spotted Salamander
Yellow-spotted Salamander - Ambystoma maculatum
These amazing salamanders had their night at the pool last night.... I'm thrilled to have again witnessed that event.
Just think; soon all those hundreds of salamanders will disappear into the woods for another year.
Meanwhile, back at the quiet pool, some fascinating things will still be happening with the salamander's eggs.  (see the links above )

Saturday, March 3, 2012

The Rock Cap Polypody -or- Ferns On A Random Rock Part 2

   The Rock Cap Polypody, also called the Common Polypody, (Polypodium virginianum) drapes gracefully over this rock. I recently (at random) picked that small center rock for a closer look at its plant community. Since the Rock Cap Polypody grows right on the top of this rock (just like its name suggests), I'm posting about it first.
 The Rock Cap Polypody is a medium-sized evergreen fern.
This fern seems to love growing on rocks.
 The fern can be found growing in a small cluster from a crack in a rock or from a cliff face.
Common Polypody  Polypodium virginianum
 The fern is also encountered in colonies, like this Polypody patch capping the large flat boulder on a talus slope.
Rock Cap Polypody ferns have a distinctive look... see the photo of the Polypody frond below.
Rock Cap Polypody - Polypodium virginianum
The leaflets, or pinnae, almost seem to zig-zag up the frond.
Here is a photo of the sori, or fruitdots, of the Polypody.
Sori of the Common Polypody, Polypodium virginianum
   This close-up (below) picture of the Polypody's sori reminds me of a row of big hair-dos from the '70's.
Actually, the sori are more interesting than they appear.  Even though these photos show spent spore cases (Polypodies release their spores in the fall), they remind me of the fascinating hygroscopic movements of the sporangia as they catapult their spores.

 Each sorus is a mass of sporangia.  Here is a photo through my microscope showing a spent sporangium near the tip of the pointer. It looks like two clear cups connected by a spring.
  The annulus (the "spring") is wrapped around the capsule from the stem up over the top of the spore containing capsule and down to about the 4 o'clock position.  As the annulus dries, it tears open the capsule, revealing the spores in their "cups"... ready for launch. Later, as it dries further, the annulus snaps forward and launches the spores in a manner similar to a catapult.
Yes, ferns have an ingenious spore dispersal system.
  There are many rocks on the mountain which are capped with Polypody ferns.  There are many other rocks, like the rocks in these two pictures, where the ferns may have recently gotten their foot-hold with the help of the fern's effective hygroscopic catapult spore dispersal system.  Once established on the rock, the fern can also spread across the rock by means of spreading rhizomes.
   The young fern in this photo looks like a fairly new arrival on this moss and lichen covered rock.  I wonder who will win the competition for the rock's surface: the moss, the rock tripe, or the fern?  Perhaps someday a Polypody colony will "cap" these rocks and drape gracefully over the cliff face where the ferns can nicely catapult their spores into the wind.  Presently though, the fern, lichen, and moss are sharing the rock just like they are on the Random Rock of this post series.
See Random Rock part 1