Native Plants, Habitat Restoration, and Other Science Snippets from Athens, Georgia

Friday: 29 January 2010

Public Service Announcement  -  @ 16:51:32
As with their biological cousins, you seldom come to know how you caught a virus, or how your computer became infected with an electronic one. Despite all the precautions and adherence to good common sense, it has happened. Maybe from a virtual toilet seat, but no doctor would believe that, now would they? Mmm hmmm.

I claim dust on my mouse, which at least sounds credibly dirty. The cursor wandered, I think, without my awareness before I clicked, to the side of the page of a trusted blogger who chose without concern to let advertisers take over that very clickable side of his (her) page. The equivalent of that toilet seat. Mmm hmmm. Sho 'nuff.

This one was a particularly noxious virus. It popped up yesterday as "XP Guardian 2010," goes by several other names, and as I gradually discovered, set about disabling my usual antivirus software so it couldn't scan. It emerges everytime you attempt to execute a program, and will not allow you to use a browser. Ironically it emulates trial windows antivirus/firewall protection software, periodically presents a list of fake infections, and popup windows every thirty seconds or so telling you you are infected, invaded, infested, and basically screwed. But you know that by now. The only cure, it would seem, is to give them your credit card number so they can send you the whole package.

Fortunately Glenn's computer was not affected so he was able to do the dirty work and come up with a solution. My Anti Spyware had a set of directions, only the slightest bit complicated, that had me load a little fixit routine into my registry and remove the rogue's distortions. Then Malwarebytes, suitably downloaded and executed, scanned and rooted out the offending virus. That was it. I was expecting a long treatment of arsenic for syphilis and what I got was a quick antibiotic.

It does make me sweat to have to deal with the registry. *That's* scary. But the script from My Anti Spyware worked perfectly to repair it.

Our antivirus software, from AVG, apparently did not have this particular signature on its definitions, since the virus gained a foothold unimpeded. Once activated, the virus disabled AVG so it couldn't take action even if. It was a little like CDC failing to include the very flu virus that actually wreaked havoc in 2008 in its triple flu vaccine for that year.

I will say though, that once Glenn notified AVG, they replied immediately with clear instructions for obtaining files of diagnostic data from the infected computer so they could try to figure out a solution. Eventually that came to nothing since Malwarebytes had taken care of the problem but AVG did respond in a productive manner.

It does cause me to ponder the unbelievable degree of sociopathy that it takes to write a rogue virus program that is so thoroughly obnoxious, and to no particular end that does even the sociopath any good. I've been told by *revere*'d experts that no one would unleash a potent biological weapon because it would hurt them as much as it would hurt their adversary. Hah.

Wednesday: 27 January 2010

Pipe Dreams  -  @ 06:01:14
A few days ago I presented a decidedly low and wet place in the floodplain alongside Goulding Creek in the western portion of the property. In comments we discussed the proper word for this wet area. Vernal pool doesn't quite make it, for geographic, hydrologic, and seasonal reasons (although different people have different rigors of definition for this term). Still, moderate rains will create standing water that can persist for days, and the pool, although only a few inches deep, harbors right now a multitude of chorus frogs.

Woodland hollow (although it's not much of a hollow), occasional wetland, and occasional puddle seem a little more descriptive.

Whatever we call it, here's something I didn't show. I paced this ditch out to about 200 feet, leading behind me to Goulding Creek, and ahead of me to the occasional puddles. The ditch is about a foot or two deep at most, and runs pretty much straight though land that has virtually no slope to it. The draining water is coming at me in this photo, and the word "draining" seems appropriate.

The pink tape marks the property line. We own the property to the left of the line, although the ditch itself probably marks the boundary.

Because of its straightness and its presence in an area that is fairly level, I'd say this was a dug ditch designed to drain the occasional puddle area. The trees that grow out of the ditch look to be several decades old.

Here's a rough sketch of the area, which covers (very) roughly an acre or so. Goulding Creek runs west as shown, light green is the floodplain, the brown is a fairly steep rise. I've shown just a few of the occasional puddles. The property line runs roughly along the ditch, and then up the rise. There are more occasional puddles in the lower quadrant (outside the property line) that I didn't show. The letters A-D mark the photos and their directions of sight below.

As you look at the photo above (and A below) you can see the rise of the land above the floodplain. You can sort of make out that it dips slightly before the rise. It's that low area that accumulates water and is, I suppose, the reason for the ditch.

A is a reproduction of the photo above, looking toward the puddles. The neighboring property on the right has occasional puddles as well.

B is on the other end of the ditch, looking back. The occasional puddle marked C is draining into the ditch. You can just make out the pink tape on the larger tree at upper right.

C, below, is a photo of the main occasional puddle, and we saw that in the post a few days ago. There's a good population of chorus frogs here.

D lies just close by C, and is flanked by extensive puddling that continues around the rise to my right.

Looking at these diminutive photos, I probably should say that I think the appearance of scale has been exaggerated. The puddles are quite shallow, and individually they are not huge - no more than 10-20 feet across.

The adjoining 300 acres is owned now in two portions by a couple of land barons, but at the time I'd guess the ditch was dug, it was owned by Champion paper company. I really can't imagine why a drainage ditch was dug anyway, except as a kneejerk response to standing water, and perhaps to increase minutely the amount of drier land that could be harvested for trees. There are no plans for development of any of that 300 acres in the foreseeable future, and in any event it would be against zoning to build on the floodplain itself.

So here was my idea. I'd thought to block the ditch, of course, and increase the holding of water in the affected areas upstream. I hadn't quite realized that the property line doesn't favor us as far as the ditch is concerned (and occasional puddle C lies on the other side, too). Blocking the ditch along most of its length would also increase the water retention in areas that we don't own.

But blocking it at the top, as in B above, would affect primarily only our own property, increasing the water retention along a line that marks the boundary between the floodplain and the start of the rise, for a considerable distance. There wouldn't be much, if any, increase in depth of the puddles - the land is too flat for that, but they would remain puddly longer.

I like the idea - the status quo is acceptable, but it would be nice to enhance the wetland aspect. In just that short time I surprised two herons scouting around for frogs, and two hawks that had been hunting from the trees. More of that just seems like more good.

UPDATE: I think Diane found the term, intermittent wetland. On what I call the floodplain (the flat area between the creek and the rise to the normal landscape levels) it looks like we have four of these. The one I describe here, and another one closer to home are frequent, and standing water persists for some days after a rain. I still haven't found the limit on the one referred to as Occasional Puddle. Maybe I should call it Persistent Puddle.

Tuesday: 26 January 2010

Dancing on the Bones  -  @ 06:21:37
The deer remains I described last week have attracted some unbearably cute midwinter insect opportunists. These are fairly tiny flies, 2 or 3 mm, and these photos are the best out of three attempts over the past week. Perhaps there is a sufficient variety to give some impression. Alternative suggestions are welcome - these were fairly difficult to match up with the photos of others.

This first species was certainly pert enough, with their outsized antennae pointed boldly forward and upward (note the hairlike aristae). And they run about the bones with amazing speed, even in the cool fifty degree weather.

The antennae bring me to Prochyliza maybe xanthostoma, aka skipper flies. Apparently they're also called waltzing flies, because the males hold each other's forelegs while dancing around in a circle. It must have been a little too cool for courtship posturing because I didn't catch them doing this.

I notice that a number of the photos at Bugguide were obtained at carrion bait, which sounds like an interesting idea.

No mention is made of waltzing here, but there was a considerable amount of interaction among these equally tiny insects, as you see to the left. They fly at each other and then spread their wings while doing a little grappling behavior. Cute!

The closest I can come here, assuming these are flies at all, is Sepsis spp. Also called black scavenger flies, they are equally attracted to rotting meat, and worse! It was the presentation of the wings with their pigment spots, along with the wasplike body shape, that suggests this ID. For all I know they could be wasps, but in the lower left photo there's a hint of a flyish head.

I've only managed to get these poor photos, a week ago, when temperatures were in the sixties, and I've been sitting on them since, an almost impossible task for me. It's been colder and/or rainy since, and they haven't made an encore appearance. Maybe we'll get some warmer days and I'll keep trying for a better set.

Both Acaplytratae: (top) Piophilidae (Tephritoidea), (bottom) Sepsidae

Monday: 25 January 2010

Winter Plants  -  @ 06:36:15

We had 2.07 inches of rain yesterday, mostly in the late afternoon and evening. The evening deluge brought with it a thirty minute tornado warning, which automatically drives a hundred or more students into a central classroom. No, you can't leave to go to your dorm. No, you can't just work upstairs. You've got a cell phone which you use constantly for texting at all other times, why don't you entertain yourself with it now?

I talked briefly with Glenn to alert him, but Oglethorpe County dispatch already had the fire departments paged for notification. This process requires that they play the toneouts for all thirteen fire departments before delivering the message over the pagers/radios. By that time the putative tornado could have come and gone, of course!

At any rate it did provide a bit of excitement!

This is the good time of year to identify new plants that aren't otherwise easily spotted, and to the left we have something we've seen before, although not this particularly bountiful presentation. It's resurrection fern, Pleopeltis polypodioides, and it sits about twenty feet up in a northern red oak across Goulding Creek. It's very happy with the current weather.

We've also seen this native bamboo in another context, and I went over it quite a bit there. But now in winter, without other green plants around, I've been able to better evaluate the extent of it. It's giant cane, or canebrake, Arundinaria gigantea. This colony extends up the creek as we're looking, and back behind us for some distance. Right now it's just growing within ten or twenty feet of the bank, but it should spread.

Glenn was a little surprised that it seemed so uniformly short. There is another, larger colony considerably distant up a hill with specimens that are ten or twelve feet tall. USDA Plants tells us that the species is FACW, that is, facultative wetland, meaning that it can take it or leave it. It may not have a lot of wildlife food value, but its cover value for birds and small mammals is high.

Canebrake is quite cold tolerant, remaining partly green even after the punishment it got over the first two weeks of the year.

Saturday: 23 January 2010

Wet Places  -  @ 06:45:59

We've had an inch of rain in the last couple of days, and it will be returning tonight and all day Sunday. So far it amounts to 2.94" here for January, but averaging out over the area it's probably right at the normal value of 3.2 inches since the beginning of January.

On top of the voluminous rainfall since August, several areas of interest have appeared, here and there. Here are two places right on the southwestern edge of the property. They're set a couple hundred feet back from Goulding Creek, on the extensive floodplain. The ground rises quickly, almost vertically, to five feet or so above the level of the creek, and is fairly level along the floodplain itself.

However there are these 20' wide low areas that tend to hold a few inches of water. I noticed them last spring, and they remained at least muddy throughout the summer, even though rainfall was fairly scarce. Last week when the temperatures rose to the low 60s there were chorus frogs calling as I'd approach the areas.

This one, from last week, has a nice growth of algae that suggests a fair amount of nutrient in the water.

I don't know exactly what you'd call them. They may not be worthy of being called anything other than puddles! They may in fact be artificial, from soil compaction by the presence of heavy tree-harvesting machines some time in the past (you're not really supposed to be doing that on a floodplain, though).

From this website, they might be called (small) wet meadows:

Open prairie, grassland or savannah with waterlogged soils but without standing water for most of the year.

Trees do grow on the floodplain itself, so you couldn't call that open, or a meadow, but these areas are bereft of trees. I'd say that probably suggests they remain wet enough to discourage the growth of the kinds of trees that grow around here.

I'll have to keep an eye on them in the upcoming spring and see what they're generating.

Friday: 22 January 2010

Carcass  -  @ 07:41:32
I'll put the larger picture as linkable to this thumbnail in order to save your breakfast. In fact most of the flesh is gone but there are still remnants left. It lies on the creekside route I take to the west end of the property, so I've been watching it for awhile now.

I assumed it was a small deer, probably an older fawn, but for all I knew it could have been a pig. I thought it might be hard to find comparative skeletons on the internet but not so. There's plenty of information, photographs, and drawings. Deer and pigs are in the same order so have roughly similar bone structure, but pig limbs are shorter and broader, so I think I'm right about the deer identification.

I've enlarged the white area, including the forelimbs (I think - the head is missing), in the thumbnail above, because something about this struck me as interesting. I guess I already knew, vaguely, that ungulates stand and walk on their toes. But I hadn't considered the interesting thing that the rest of the bones of the foot/hand are modified to become a long third section of limb.

I've colored the clearly delineated leg bones according to the figure at right, which I found here. The figure shows the comparative bone structure of the hind limbs between the three major types of locomotion. We are plantigrade, with the phalanges (or digits of the fingers), the metatarsals (or carpels) of the mid foot (or hand), and the tarsals of the heel all gathered into the foot (or hand).

Deer, on the other hand, are unguligrade, that is, hoofed mammals. The hoof that they walk on is comparable to us walking on our fingers and toes (blue). Our mid-foot (or hand, purple) is modified into a long leg bone that is comparable to the lower half of our leg (or arm). And the bones of the back of our foot (or hand, yellow) are now a kneelike connection between the lower and middle sections of the limb. Since deer also have a tibia and femur just like we do, they have *three* roughly equal sections to their limbs, whereas we just have two.

Ungulates, hoofed mammals, are classically divided into several orders, but the main two are the odd-toed (horses, rhinos, etc.) and even-toed, including deer and pigs, goats, cattle, and such. The latter are in the Artiodactyla.

And here is the other interesting thing: cetaceans (whales and dolphins) and even-toed ungulates are now placed in the same clade. The classical taxonomy does not classify them together (they do look quite different, after all) but ancestral fossils of cetaceans as well as DNA analysis makes it pretty clear that whales evolved out of Artiodactyla. It seems now that hippos are the closest living land relative to whales.

I don't know what the young deer died of, of course. It's much too small to have been of interest to a hunter. I've heard and read that young deer are being predated on in large numbers by the coyotes that are now our dominant large predators, and so that may be the explanation.

Tuesday: 19 January 2010

More Flow  -  @ 06:48:38
To conclude this from yesterday's post:

Yesterday I walked down to the same submerged rock at Goulding Creek. The water was higher, and perhaps faster, than in the photo in the post yesterday, and downstream from the narrow submerged rock (upper right, white line) you can distinctly see four stationary waves (marked by the blue lines) in this photo (click to enlarge in a new page).

Actually there were five, but the fifth one along about the flow direction arrow to the lower left wasn't so visible in the photo.

Each subsequent wave farther downstream is considerably smaller and less turbulent than the previous one, but they all stand in place.

Here's an overly complicated figure that I started out with to suggest what might be happening. I'll try a simpler explanation below this figure.

As the flowing water moves over the rock, it's forced to move upward (A). This creates a bulge (upward displacement) on the surface of the water, but in addition it creates a "hole" in front of the rock into which that bulge falls (gravity) after it moves past the rock (B).

I'm not exactly sure what role friction plays. The moving layers of water close to the bottom of the creek experience a great deal of friction from the stream bed. The upper layers of water experience friction from the slightly slower moving layers below. I suspect this has an additional role in carving out sediment holes (C) in the bed periodically downstream from the rock, and that these help to create the "standing waves" atop. That may be a secondary effect that you wouldn't see immediately after placing the rock in the stream. An additional friction effect is that the bulges are subsequently reduced in size as the disturbance moves downstream.

Nothing particularly wrong with that description, but it seemed to me that there was an easier way to describe it if you accept that with that rock interrupting the flow, we've created a wave.

Just like in the figure above, the wave is created by displacement upward of the bulge of water as it moves over the rock. The new thing here is that the wave is being constantly created, giving the appearance of a standing wave downstream from the rock.

Now, since we've created a classic kind of wave, it undulates up and down as we move downstream. I'd guess it's friction and other secondary effects that quickly damps the wave down.

That's a much simpler explanation, isn't it?

There's even an analog that you might be more familiar with, and that is the undersea earthquake that causes a tsunami.

Instead of water flowing over a rock, an undersea earthquake may cause an entire section of sea bed to abruptly rise upward (or fall downward). When seabed is lifted, a bulge of water is hefted above the rising seabed, and the tsunami wave is started. Such a tsunami may reach a coast with no warning.

(By the way, if the seabed drops, instead of rising, because of an earthquake, the water above falls into the space that's created. You still begin a wave, but this time, at the coast, the ocean will draw back before the peak of the wave arrives. This is the more familiar scenario that gives at least some warning before the damaging tsunami arrives.)

There is one additional little detail. In the first photo above you'll notice there's a little turbulence in the form of a breaking wave atop the first two waves. Here they are, with the blue arrow showing the direction of flow and hovering above the rock:

There's a simple relationship between the amplitude of a wave, and its elevation above the seabed, that describes when a wave can no longer support the water that it's carrying. You see this as breaking waves on a beach as the wave moves into shore. Here the first wave or two after the rock are "shallow waves". The height of the wave is greater than the depth of the creek bottom, and breaking occurs.

The wave dampens in the next two or three crests downstream, and becomes a "deep wave" with respect to the creek bed, and you don't get breaking.

(Odd that the turbulence seems to be occurring on the leading edge of the wave in the first, larger one, and then only at the top and perhaps both sides of the wave in the second smaller one. I would guess that little detail may have a lot to do with the geometry of the creek bed, but that's certainly beyond my scope to figure out).

One more analogy. If you've been on a large boat moving at a good clip through the water, you'll have noticed that sternward are produced several distinct "standing waves," becoming smaller as the distance from the boat becomes greater. It's the same thing, really, except that in the analogy the boat, rather than the rock in my creek, displaces water from above (rather than from below). Also it's the boat that's moving through still water, rather than water moving over the stationary rock. But it's the same thing.

There. I got through that without having to explain the difference between laminar flow and turbulent flow. Whew!

Monday: 18 January 2010

Getting with the Flow  -  @ 06:59:51
It's probably clear by now that I love Goulding Creek. I like its name, which derives from a Wolfskin militia captain along about 1800. I enjoy seeing it in its changes, which mainly come with a lot of rainfall, or the lack of it. It's not very spectacular, usually, because there's not much of an elevation drop, but even in the driest of years it's been entertaining and has certainly provided its share of blog fodder.

Goulding Creek begins a little north of US 78, known around here as Lexington Highway or Athens Road, depending on which way you're going, or Main Street, if you're farther east in Crawford. There are three or four major branches that feed it along its major three-mile course until it gets to the impoundment of Lake Oglethorpe, about a mile in length. A little less than a mile downstream of the dam it gets to us, and much of its behavior is anomalous because of the lake upstream. And then it flows along, fed by several feeders, for a couple more miles until it joins with Moss Creek and becomes the rather more spectacular Big Creek. So it's not a very long stretch of moving water.

This weekend we had 1.87 inches of rain, and it swelled the creek a bit from its usual leisurely flow. I'm getting to know the long stretch that accompanies the new portion of the property, and enjoyed the walk downstream yesterday as the creek meandered through.

There's whitewater ahead - you can see it! I'm afraid Goulding Creek whitewater isn't much to talk about, unless you start getting erudite.

I have to tell you that I feel a moment of erudition coming on. This photo of what I think is a fascinating phenomenon may clue you in. Why do you have these backward standing waves just downstream of a submerged flattish rock? Why do you have two of them? Though you can't see it here, why are there concavities at the bottom, layered with larger rocks but no silt underneath each crest?

More later!

Saturday: 16 January 2010

Dinner Tableau  -  @ 05:30:19
Occasionally I run across a little scene like the one to the left. Someone came to dinner. I'm guessing this was the handiwork of a hawk or owl.

As for who was dinner, red-bellied woodpecker, our most common species, comes to mind, although I see no evidence of red feathering. Here is the page for woodpeckers in the The Feather Atlas. (Which, by the way, is pretty cool.) I don't see any long bar such as is present in the bottom feather below, but otherwise the shapes and numbers of the bars look fairly close. Downies and Hairies have markings more in the manner of circular spots.

It's a hard world!

This discovery, incidentally, led me to the Migratory Bird Treaty Act (1918 ) between the US and Great Britain (Canada). That in turn led me to northern rockhopper penguins which was appealing because they live on Tristan da Cunha and Gough Island in the South Atlantic. Oddly, rockhopper penguins are also found on two islands in the Indian Ocean.

Friday: 15 January 2010

Kepler and the Search for Earthlike Planets  -  @ 06:46:50
A few weeks ago we took a tour of some of the extrasolar planets that have been recently discovered. I alluded to several methods used to detect these exoplanets.

Here's one of these methods - the transit method. It's pretty easy to understand, and the two figures below should help.

On the left we have a planet that just happens to pass between us and its star, as it orbits its star. It's in the right orientation, and when it transits, or crosses in front of its star, the light from the star will be diminished a tiny amount for a short period of time, and that is what is detected. It's a very tiny effect, and it becomes more difficult to detect the smaller the planet and the farther away it is from its primary. This explains why the majority of detected exoplanets to date have been hot super Jupiters, those very large planets that orbit close to their sun.

But there's another problem - using this method, only a small fraction of exoplanets can be detected at all. On the right we have a planet, which like most, will *never* pass between us and its star. It will remain undetected because it will never diminish our view of its sun's light.

By using the transit method, we can detect the planet orbiting the star in the left hand panel. We cannot detect the planet in the right hand panel, since it never passes in front of its star. For earthlike planets orbiting at a distance similar to the earth, only 0.5% will be detectable, assuming a random distribution of orbital inclinations. Those detected will be the ones that just happen to be passing between us and their stars; the rest (99.5%) never come between us and remain undetectable by the method.

Most of the exoplanets, in fact, have been discovered by another method - the radial velocity method. Unfortunately it also works best when the exoplanet comes between us and its star.

We're doing this now by using both space and land based observatories, with a number of detection methods.

Enter Kepler. Its mission is to discover planets.

Kepler is a space based observatory that was launched in March 2009. It took a few months for it to achieve its ideal orbit, which is an earth-trailing one. It actually orbits the sun, behind the earth so that it has an unobstructed view of the sky. For the next several years Kepler will stare at a patch of sky about the size of your hand when extended at full arm's length. There are about 100,000 stars in this region, and Kepler is looking for transits.

What are Kepler's eyes like? Well, it just has one, really, but that 3-foot optical barrel will focus onto an array of CCD (charge coupled devices), just like you have in your digital camera. The difference is that Kepler has 42 of them. And instead of taking a quick snapshot like you do, Kepler lets the light from the stars fall on the CCDs for 30 minutes before it "snaps" the picture.

From the Kepler Mission Page Quickguide: that optical barrel is only about 3 feet across, so Kepler is large enough to make an impressive addition to anyone's living room, yet small enough to not overwhelm the baby grand.

Kepler has now "rediscovered" three planets already known in that region - that was a sort of control challenge to get the observatory up to speed. And now it has discovered five new planets. You can keep track of Kepler's findings at the NASA Kepler page.

Here is an example of the data that Kepler acquires. You can actually do a search on Kepler's findings here, although the search form isn't easily used. That's how I got the figure below.

A sun without planets transiting would have just a straight line across (other than variations in the sun's brightness). The dips you see here are a planet moving in front of the star over a short period of time. The changes last from 2-16 hours, and must be sudden and perfectly periodic to be a planet.

This figure shows Kepler 5b, a super Jupiter with an orbital period of just 3.6 days.

That figure was a blowup - if you look at the actual data, here is what you see:

It's going to take around three years for Kepler to identify *and confirm* planets that are in the habitable zone, i.e., about the same distance as earth is from its sun. The reason is that those dips that you see in the star's light in the figure above will occur cyclically like that one, but only once every several hundred days. Kepler will have to wait that long to confirm its first observation.

Again, from the Kepler Mission Quickguide, here are the predictions, from past experience, of what Kepler is expected to find over the next 3-5 years. Remember that this is what is predicted from a very tiny region of observable space:

Over the next several months, Kepler will detect by one method or another perhaps a thousand super Jupiters in close orbit around a star.

Our greatest interest is in the planets that are earth-sized, more or less, where 1.0 RE means earth sized, and which have a transit that occurs about once a year. These will require around a year after first observation to confirm. The Quickguide says:

From transits of terrestrial planets in one year orbits [ed: that is, those with temperatures most like ours]:

* About 50 planets if most are the same size as Earth (R~1.0 Re) and none larger,
* About 185 planets if most have a size of R~1.3 Re,
* About 640 planets if most have a size of R~2.2 Re,
* About 12% with two or more planets per system.
The sample size of stars for this mission is large enough to capture the richness of the unexpected. Should no detection be made, a null result would still be very significant.

Imagine that. Over the next few months Kepler will be adding up to a thousand giant planets to the list, and you can actually keep track of what it's finding. And then, starting in the next year, there may suddenly be known at least fifty new earthlike planets. Maybe as many as 900 such, if you relax your principles to accepting the very large earths, up to twice the size of ours.

And remember that that's only the tip of the iceberg. Kepler can only report what it sees, and it doesn't see the vast majority of planets that don't move in front of their stars. Whatever the number of earthlike planets is discovered in this tiny region of space, there are probably 100-200 times more.

So if the hypotheses that lead to these numbers are right, then we'd expect that out of the 100,000 stars in the experiment viewing this extremely tiny part of our galaxy, we might have 5000-10,000 earths. For most of my life, the question was always "are we alone?" And now, in just a year or three, we will begin to have the answer.

Tuesday: 12 January 2010

Continuing the Beaver Saga  -  @ 07:04:50
Let us continue thinking about what's going on with the putative beavers, and for the moment assume that that's what we're seeing.

Yesterday I continued the investigations of the evidence. Across the creek (on our side) from the three cut sweetgums I found a couple of days ago were two more, smaller cut sweetgums. I can't swear they weren't there then, but again there was no remainder of the trees that had been cut down.

I walked a considerable distance upstream of this point. I found no evidence of beaver construction or tree stumps along the creek, so it does seem to be limited to this 200-foot stretch, concentrated along the northwest corner of the property.

Beavers don't always build dams, and if they do, they may not build a lodge. It seems that the primary motivation is to create a reservoir of deeper water for predator avoidance. If they are present and don't build dams or lodges then they're residing in holes in the creek banks. Glenn relates that he's read that beaver entrances to any den, whether it is a lodge construction or bank den, lies underwater. There are many places along Goulding Creek where there are holes and undercuts in the creek banks, but not many places where water is deeper than a foot or two at normal flow.

Here's a typical cross section of Goulding Creek. The creek runs through a flood channel, and you've seen plenty of photos of this channel and its enclosing banks. It varies, of course, but the channel banks may be ten feet above the normal flow level.

Outside of this channel is a floodplain, relatively flat, that may be narrow in places before the surrounding terrain begins to rise. Or it may be several hundred feet wide, as it is on our side in this area. At the far left and right in the diagram above the terrain rises fairly steeply to a more typical elevation, 50 or more feet above the normal level of the creek, the "house level," as I've indicated it. (You're not supposed to build below this level.)

My point here would be that it seems unlikely that a beaver pond would rise much farther than the "worst case scenario" I've indicated in aqua. That doesn't mean that a pond filling the flood channel (and for some distance upstream) wouldn't have a considerable impact on the nearby portions of the floodplain, but I'd think it would take quite a width of beaver construction to create a pond of any depth that was broader than the twenty or so feet across the flood channel.

I've long puzzled over this little area on the other side of the creek, involving about 100 feet of the creek course, and going back perhaps 50 feet from the creek. In the photo below, which I took on our side of the creek, the blue line marks the creek itself, which you can't see because it's below the angle of the photo. The arrow actually shows the position of the three cut trees that I found a few days ago. And the yellow dotted line shows a depression that runs between this mound in the foreground and the floodplain in the background. Back of the yellow dotted line looks to be the edge of the bank that you can see in full, left center in the second photograph below.

I'd speculate that this is added land resulting from some persistant obstruction in the original creek flow, and that Goulding Creek formally ran along that dotted line until the land got built up.

Here's a photo taken from a bit upstream, looking back back at the "island." Notice the undercuts in the bank in the foreground. There is a secondary depression that could mark an intermediate channel through which Goulding Creek flowed as the land hypothetically began to pile up to the right. And at the left end of the yellow dotted line is the high bank whose remnants you can still see back of the length of the yellow line.

About the same position, a little farther back. I'm thinking that this "island" is actually an old beaver dam that changed the course of the creek, and that this may be the site of habitation. The undercuts may hide entry burrows into this mound.

It's interesting that some overlays of Goulding Creek show a channel that no longer exists, circled in red on the left. That kink would be of the right size and position for this "island." I recognize the terrain and changes in the creek course both above and below this point - it's quite accurate otherwise.

You'll notice the trees growing atop the mound. None of them is very old - I haven't tried to estimate their age. That's fairly typical of all the trees growing on the extensive floodplain that I'm standing on in taking these photos - they're all fairly young, certainly under fifty years. Glenn has found this a little odd, as though the floodplain has only recently become conducive to tree growth (alternatively, it's been extensively logged). Certainly once you begin to walk back uphill above the floodplain there are many trees that are much older.

Surely there are ways to test these speculations, and the first would be to get the wildlife cam in a position to observe this particular area of activity (as has been properly suggested in recent comments!).

Sunday: 10 January 2010

More Tricks  -  @ 14:13:30

Looks like another prank was played on me!

This was about 200 feet upstream of the last trick. The trees, of which only one remains, are larger too, by an inch or two.

Looks like a daytrip upstream is in order! It's been too cold though, with the ground frozen solid each night of the last week or so, for anyone to leave tracks.

Friday: 8 January 2010

The Month of December  -  @ 07:30:20

It's The Month of December, Number 47 in a series. A little late, but better than never although the memory of it may be fading now. Our little event yesterday turned out to be even littler than thought. A few unhappy snowflakes were squeezed out of a sky too dry and temperatures too warm, and that was about it.

The usual temperature anomalies product was broken at National Weather Service Climate Prediction Center, so this plot of mean temperature anomalies for the US came from the ENSO update and is in Celsius this time. That's the difference in the average temperature for this December above or below the average for December over many years, plotted in colors.

Just about everywhere was cooler than usual in December, except the extreme northeast, portions of the southwest and northern midwest, and the Florida peninsula. And they weren't hugely above normal. From the Rockies eastward into the midsection the temperatures were the coldest. For most of the US this was a switch from an unusually warm November.

The National Weather Service Climate Prediction Center seems to have finally stabilized the location of their precipitation plots here.

After all the brown of November, there was a lot of precipitation in numerous locations. The Atlantic and Gulf states were especially wet, as was the northern half of the midwest. The Rockies and southern California received more precipitation than usual. For a lot of this the precipitation was in the form of heavy snow.

For much of the US, this was a continuation of monthly switches from dry to wet, beginning in September. The Pacific states, and northern California continued dry in December.

For Athens:

For Athens, the rule was somewhat cooler than usual and for the fourth month in the row remarkably wetter than usual.

Here is my plot of low temperatures for the month of December in Athens. (It seemed appropriate to present high temperatures this time.) As usual, the black dots are for the 18 years 1990-2007 (black dots), 2009 (green line), and 2008 (red line).

We broke no records, although December's nightly temperatures were mildly cool. The same was true for the daily highs - trending a bit below normal, but not remarkably so.

We had 2 days of high temperatures that was at least one standard deviation higher than average, and the usual number of such days is 5.6. We had 3 nights below the standard deviation for our usual lows, compared to 4.4 such nights. It seems that both our days and nights have been slightly below norms.

That's where unremarkable ends. In December we had a repetition of the rains of October, September, and November. This has been discussed here, so I won't belabor it except to say that it was an exceptionally wet year, and due mainly to large amounts of rain the autumn and December.

The figure below shows the Athens data which are official for our area. As usual the green line shows our actual rainfall, the red shows the average accumulation expected. The black dots are rainfall over the last 19 years, the vast river of peach shows the standard deviation. The blue emerged as surplus this from the very beginning, and never let off - we ended up with 5 inches more rain than the usual 3.7.

Athens offical rain since September (inclusive) - 32.9 inches. Normal for this four-month period, 13.5 inches. That's got us down to about 11 inches of deficit since the drought intensified four years ago. At the worst moment we were 31 inches below normal, in midsummer.

I'll continue to link to this neat prognosticator in which you can get variously timed precipitation and temperature outlooks. El Niño seems to be having an effect now, and you might want to check that out. The current 1-3 month option shows us having unremarkable weather, other than cooler and wetter temperatures. From the ENSO website, here's a probability map for the season Jan-Mar. Above and below normal temperature probabilities are on the left panel, and the same for precipitation on the right:

NOAA's weekly ENSO update has not changed since last month. We're now well into an El Niño event of sustained proportions. It has continued to intensity, and is projected to last through spring 2010, and possibly into summer.

Relive your favorite weather events of the year 2009, courtesy of NOAA. NOAA has a neat State of the Climate product. By clicking on the year, such as 2009, you can get to monthly and even weekly reports and zero in on regional descriptions that are much nicer than my own.

Thursday: 7 January 2010

Minor Mystery  -  @ 07:21:32

Along a bend on Goulding Creek, I came across this young sweetgum, about three inches in diameter, cut off about a foot off the ground and right next to the creek. It's the only cut tree in the area. I did not find the upper portion.

I can think of three explanations - human, beaver, and rabbit. I can't refute the possibility of human other than that if I were snipping with some cutting tool, I wouldn't do it from the bottom up as this seems to have been done. I'm also skeptical at the human presence possibility, but can't deny that someone might have been playing an amusing little prank.

The size seems to be on the margin of possibility as far as rabbits are concerned. I also can't refute beavers, but I do pay attention to tracks in the mud and sand and haven't noticed any distinctive beaver tracks. Beavers are not unheard of on Goulding Creek, but in my wanderings I haven't seen any convincing evidence of them. There is a pile of sticks and debris in the creek nearby but I would have attributed that to recent flooding rather than construction.

Kim Cabrera has a nice page on beaver cuts. Most of the photos show beaver cuts at 90 degrees, with a 45 degree cut like this one mentioned as a rabbit possibility except for the size of the branch. For what it's worth, there were two sizable chips under the cut - I didn't take a ruler but could correct that oversight.

Wednesday: 6 January 2010

Last Week on the Beech  -  @ 06:06:44
I ran across these two arthropods sunning themselves on a beech tree trunk, just above the creek. It wasn't as cold a week ago as it is now, but it was still in the mid 40s.

This one I'm fairly sure of. Dolomedes tenebrosus, fishing spider, I presume. Poor thing only has two right legs.

This one, on the other hand, is one of those throw your hands up in the air sort of things. One of those confusing wasps, and even there I'm not sure. Quite small, a centimeter or so, and just a foot from the spider. Two ovipositors? A brachonid or ichneumon? It's not fair to be confused in the winter.

Apparently the difference is the presence of one or no recurrent wing veins (brachonid) or two (ichneumon). Looks like there might be two recurrent veins here but since the insect may not even be a parasitic wasp, it's probably all moot.

UPDATE: Thanks to Heather for identifying the insect as a stonefly (adult female). It's a good reminder that there are more orders of insects than I usually focus on!

As for snow tomorrow, the forecast has been bouncing back and forth, with varying degrees of pessimism about moisture in the air. At the moment it seems to have settled on a safely noncommittal 40-60% chance, with zero to one or two inches of snow, either accumulation or none.

And to add to the fun, Thursday is the first day of spring semester classes ; - )  .

Tuesday: 5 January 2010

How Cold Is It?  -  @ 06:47:15
Cold enough to put a thick skin of ice on the ponds, something that hasn't happened since considerably before I had a digital camera. That was probably around Dec 2000/Jan 2001, just looking at the monthly lows in my database.

It's a good thing too, for Maxwell didn't think twice before venturing out onto the ice, yesterday morning.

The days haven't broken 40 degF for four days, and with the nights in the teens we could get lucky and on Thursday have some snow that sticks around for awhile.

It surely won't get cold enough to freeze even SBS creek, which babbles along quite merrily now, but the spray from this mighty waterfall down Troll Rock did coat the dead grass stems with nice bulbs of ice. Should look very good this morning.

That brings us to our new cat, Sophie. She's not really new - we've had her now since October, but I haven't found the proper moment to introduce her. But it's cold, and she's large and warm and loves the cold, and that seems about right.

She had a terrible 2009. Her original owners, an elderly couple living here in Oglethorpe County, a bit north of Lexington (about ten miles from us) were killed by a pack of dogs back in August. I don't know (or won't get into) her subsequent detailed travails, but eventually she came to the attention of our neighbors who inquired if we were in a position to take her in. We were. When you have nine cats, contemplation of a tenth is a mere technicality that in the matter of Sophie easily transformed into establishment of residence.

She's a Maine Coon, about six years old, but her delightful personality would have charmed us even without having had a couple of Maine Coons long ago. Pete and Petra had been our only purchased cats - a brother/sister pair of pet quality Maine Coons, back in 1980. They were dear animals and actually made it to Sparkleberrysprings for a few years. The two dozen or more cats that we've taken in since have been strays and needful adoptions that we understood were more important to care for. Sophie fits into that group.

Sophie has quickly demonstrated a number of the Maine Coon characteristics that we'd pretty much forgotten. She's large (18 lbs) but not fat, rather the cobby solid build of the breed. She has the ear tufts, the thick silky fur that you'd expect, and the large paws. She's a friendly, affectionate cat, and although she does have a small voice her main mode of communication is the constant comment of various trills that any Maine Coon admirer will recognize.

A note on introducing a cat into a household, since this is something that often comes up that we actually know how to do with good success:

Her first few days were spent in the upstairs bathroom, and that was clearly the right thing to do. She had the opportunity to get used to the other cats' odors and sounds, and they hers, to some extent. It only took a day before she was greeting us and showing us in, but it was a week before she asked to come out. At that point there were no problems other than the occasional hiss if she ran into another cat unexpectedly.

She has now pretty much established herself as alpha cat, if there is such a thing. She maintains her status through a firm application of laissez-faire noblesse oblige. Not even Gene, the previous alpha cat, messes with her. If he does get out of hand, she will stalk him relentlessly in the manner of Helen Thomas in the Stephen Colbert fantasy video of a few years back, and he doesn't like that at all.

Sunday: 3 January 2010

Hunting Season Over!  -  @ 05:00:45
The extremely cold weather that's affecting everyone in the north and central US is now affecting us too. Temperatures won't be going above 40 degF at the highest for at least through next Saturday, and down into the teens at night. Which is cold for us.

So yesterday was not only the first day in quite some time that I've been able to take a long walk down Goulding Creek, but it was also 30 degF and windy. Out of deference to the hunters (usually a good idea), I hadn't checked the two deck openings after last September to see how they'd been managed. Here is Deck 2, which looks to have been mowed and disced, then planted. The main point is that it's being kept clear. Across the way there the terrain dips way down to Goulding Creek, and then back up to Black Snake Road which runs horizontally along the top of the ridge.

I was pleased to see that there was no trash anywhere, including under the several deerstands in the area.

Halfway back along Goulding Creek I encountered this bold little bird, which seemed to find me fascinating enough to come close and hold still.

I'm guessing it's a hermit thrush - at least the indications are that that would be only thrush we'd see this time of year. Everyone else is wintering much farther south.

The spotting, and extent, is right.

And the russet tail color does not extend up the back, which is more of an olive brown. I see in retrospect that it's sitting in privet, probably partaking of berries and thereby dispersing the invasive plant. Oh well. Actually I should check that - we do have one native swamp privet, but chances are poor that this would be it.

In the spring we'll get a lot more thrushes migrating through on their way north, and hermit thrushes will leave us as well.

A few thumbnails of slightly different poses, in case there's any question.

Saturday: 2 January 2010

The Year of 2009  -  @ 04:34:27

Our annus mirabilis:

The year of snow,
The year of rain,
The year we had
Little cause to complain.

Flashback to 2007:

If only I had been recording measurements in 2007, our annus horribilis!

Then you could have seen some temperature extremes!

With the end of the year comes the final addition of temperature and rainfall measurements to the excel worksheets, and the completion of the following graph. It follows temperatures (around and about the bell curve) and precipitation amounts (bars at the bottom).

For temperatures, the blue is 2009 here at Wolfskin, and the red is 2008. The cloud of dots are the actual measurements, usually a half-dozen times during the day. The jagged blue and red curves are 2009 and 2008 25-point moving averages, so you can see periods of significant heat or cold waves. The smooth purple bell curve is the official daily temperatures averaged over many years.

Do yourself a favor and get a larger version by clicking on the figure.

2008 was much less extreme, and 2009 even less so. Take summer, for instance. The red dots indicate that we went over 100 degF on only two days in 2008. 2009? None at all - our highest temperature was 97 degF and we went over 95 degF on only six days. Heat waves? None really - a few hot days at the end of June and then again in early August.

How about winter? Our coldest temperature in January 2009 was 14 degF; in 2008 it went slightly below 17 degF, an unusual November 2008 cold wave. Our deepest and longest 2009 cold wave came with the snow on March 1.

The big story of 2009, here at least, was the rainfall. You can see from the bars at the bottom that it was the last four months of the year that did it for us, pushing Wolfskin to 64.70 inches in the last couple of rainy days of 2009. That's about 16 inches above normal. We had two inches or more in a day on nine days during the year, seven of these in the last four months.

2009 even tops 2005, our last year with a surplus. 2006, 2007, and 2008 were well below normal (the red line), in the 30-40 inch range:

Since 1920, Athens has topped 64.70 inches in only five years: 1936, 1948, 1964, 1967, and 1929 with the greatest total of 72.4 inches.

What, in the end, did this do for our rainfall deficit?

January 2006 was the beginning of a drought that reached its nadir of 30 inches below normal in August of this year. The last four months added enough rainfall to bring us to just 11 inches below normal (the blue line, right axis):

Finally, from NOAA, the precipitation anomaly over the 365 days of 2009:

The current strong El Niño began, in retrospect, in the May-June-July "season." If we consider the odd weather to have begun in September, and driven by El Niño, then there would seem to have been about a three-month delay before the effects began to be perceived by us.

Friday: 1 January 2010

Happy 2010  -  @ 07:32:25
2010. Isn't that the year we made contact? Welcome to the future that never was!

Happy New Year to everyone! Today is 100101, which not only has a certain binary charm, but which we also don't have to worry about for ninety years until it's Y2.1K. (Note that you also have the calendar concern trolls emerging from under their millenial rocks to object that it's not the end of the decade yet - that will come in 2011. They've been nursing their wounds from ten years ago, so they're fresh and ready for blood. Sure they're right, but no one listened then either.)

Time for a weather porn report for the year - but we'll deal with that later.

Yesterday was the day to clean up for the incoming year. New file structures! working/climate10, blogs/blogs10, and pics/2010/100101whatever.jpg. Learning how to write 10MMDD instead of 09MMDD! Creating temps10.xls from the past year's temps09.xls. All sorts of pre-2010 duties.

It's always a bit of a shock to hear or read of others whose deer hunting season lasts only two or three weeks. Ours lasts for nearly *four months*, beginning in September and ending... TODAY! For the first time in three and half months I'll be able to take a walk along the new property. And that, of course was a major series of events during 2009.

And about 8pm on Wednesday, within a few hours of exactly a year after last year's New Year's Eve fire call, we got a call for a chimney fire on Wolfskin Road. Since this was our own fire department's Secretary, we had considerable incentive.

Fortunately the fire was confined to the chimney, which served as the flue for a wood stove. It had not progressed very far. I arrived first with the new old pumper, and Lisa directed me across the front lawn to the back of the house for easier access. With the able aid of Crawford, the fire was extinguished without the need for water (which would have been a horrible mess), we had a high powered ventilation fan in place to get the smoke out of the house, and we *should* have been done.

But, the ground was soggy from recent rain and we got stuck. Nothing worked to get us out, not even dumping our four tons of water to lighten the load. After digging the rear tires deeper and deeper into the ground, we called good old Gabriel's and they towed the pumper out. We did get home before midnight. Yesterday Glenn and I took the pumper to refill it. I used the booster hose to wash off a fair amount of Lisa's back yard onto Double Bridges Road, before Brian saw it.

That brings us to chimney fires. The reason for chimney fires IS the season, and we often expect these anytime around and after Thanksgiving, when people light the first fires in their wood stoves. What has happened is that creosote deposits have built up inside the chimney flue to the point of igniting an extremely hot self sustaining fire inside the chimney. While it might be contained within the chimney, it can throw off sparks and fire above it that ignite the roof, and the intense heat can also ignite adjoining wall.

The firefighters have an extinguisher there at the top of the chimney. Probably a good idea but directing an extinguisher downward is probably not as good as directing it upward from the bottom. More than likely it's an allocation of resources, much as our charging of a hose with water was, even though you hope you won't have to use that.

You might recall chimney sweeps as a quaint historical figment of Mary Poppins, but chimney sweeping is a viable and present day profession. Chimneys should probably be cleaned at least every other year, depending on use. The image above is not my own, but comes from here, which also has some good tips on chimney cleaning.

It's a little late for it, but the best advice I've heard (and witnessed) for avoiding fires while on vacation is this: Don't just turn off, but also unplug all unnecessary devices before you leave. And turn heating off, or at least down to whatever minimum you think your empty house can tolerate.

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