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

Wednesday: 21 May 2014

Box Turtles of May  -  @ 09:51:36
So far, anyway.

I've mentioned that my encounters with box turtles have seemed rather unsuccessful this year. It's true that I found none in March, and April seemed sort of disappointing too. But when I look at actual box turtle activity (number encountered relative to the time I spent looking), I find things weren't really all that bad:

2012 is shaping up in retrospect to have been an anomaly, and I attribute that to the extremely warm March that year.

In 2014, I just haven't been on as many walks as I took last year. There is one caveat: I've been more selective based on past experience. April was either cold and wet, or warm and very dry, with few days that would inspire a box turtle to emerge. I tended to focus on those days, plus the warm ones regardless. And one previously seen turtle was dead, of course. I think that if I had been more random in the sampling, then I would see April's activity go down quite a bit.

May is still in the works, of course. But I've accumulated a few points of interest. Two new turtles in places that I've sampled extensively, three old friends, and an odd appearance.

Two for ones are always gratifying. Glenn said that it was remarkable how many turtles I've come across in the act of mating. I'm now thinking that maybe because we see box turtles as slow, we imagine that they must also be lacking in enthusiasm. I think that's not the case.

On May 12 here's Sylvia and a new turtle, who is quite dirty. So dirty that I couldn't photograph him for identifying features. I used most of my water bottle to clean him off, which alarmed him enough to disengage (except for his rear legs, which males always seem to get caught by). It was quite clear that I have not seen him before, once I went through all the composites. He also has quite a bit of damage to his frontal marginals, which look like they've been substantially chewed upon by something. If I find him again, I just might name him Pigpen.

As I've mentioned before, I started using a hanging scale to weigh turtles (when possible). The male here weighed 410 grams, which is insignificantly larger than the average 402g (+/- 67g) for the 38 male weights I made last year. What was odd was that he was 14.5 cm long, which is just about the longest male I've ever found. It challenged my 6" ruler for the first time!

Sylvia, who I've now found mating three times since last year, was 430g, just under her 446g (+/- 11g) average last year (n=5). At 445 +/- 58 grams (n=30), females tend to be about 10% heavier than males. This, by the way, is my 18th encounter with her since I first found her in 2006. It was great to see her again.

So why was that male so dirty? I've never found a turtle so covered in dried mud. Even early in the season they tend to be quite clean, and I've assumed they quickly get to water after digging out, or that the next rain will wash them off. Since we had had a fairly significant rain two days before, I'd guess this turtle just emerged in the last day.

It's probably also worth noting that this supports the idea that he actually did dig down for the winter, and wasn't just under a thick pile of leaves and detritus.

On May 13, I found this new turtle. He was on the upper ancient roadcut leading down to Goulding Creek. He weighed 360g, so on the small side for a male. His 19 scute rings represent only a minimal age - once you get to that number, the rings aren't very informative anymore.

I found the handsome fellow below just climbing out of the creek at the southernmost tip of my route up SBS Creek. As it turns out, I also saw him last year on June 7, for the first time, probably 50 feet away from where he is now. He needs a name now. He weighed 510g, which is quite heavy for a male (last year it was 490g).

Finally, our old friends Cory (left) and Reuben (right).

I've found Cory now 14 times since my first discovery in 2009. He's a small turtle, averaging 320 +/- 7 grams, and weighed just 300g on May 12. He's always been in the same general location, on the north slope. He's made at least one foray into the fairy ring south of the house, where I found him once last year.

Reuben, who was the first turtle I found in 2012, has been rediscovered 11 more times since then. He tends to haunt the lower half of SBS Creek, and I've found him mating twice (once with Sylvia!). He's at the upper end of the male range, at 450 +/- 11 grams, and on the 12th he weighed 460g, so has probably been out and about for some time now.

We had some unusually cold weather the last five days, with considerable rain, and I haven't seen any turtles during or since then. But we're climbing out of that cold spell now, and I expect today could net some more May discoveries.

Friday: 16 May 2014

Making Way  -  @ 08:05:22
First thing, I'm starting to find some box turtles now, so life is good.

Second thing, I'm working on the annual trails into wild country.

Wild country, below, is the leftmost (westmost) area marked in red, as "New." The part running along Goulding Creek is floodplain. The topo tells you this, as it also tells you that there is a rise to the south to a couple of shoulders that overlook the creek (if you could see it from there, which you can't). The colored lines roughly mark what I call turtling paths, designed to maximize coverage, and the light green circles cover an area of about an acre. Our neighborhood access road is in gray, at upper right.

South of the red block, all the way to Wolfskin Road (about a mile) is developed only in the sense that it's pine plantation on the uplands and old unmolested hardwood on the slopes and ravines. Northward of the red block is a similar stretch that ends at Black Snake Road.

We bought this red-marked area, "new" (plus the heavier black-marked area, "westridge") several years ago in order to add a stretch of creek, which now amounts to just under half a mile from eastmost to westmost points. It's a nice walk, but I was frustrated because by May it had become practically impossible to get through the growth. Not just impossible, but somewhat dangerous - we do have rattlesnakes and copperheads, not to mention ticks, and once the growth started you can't see the ground.

So I was only able to walk on much of this for four months of the year. We do vacate that part of the property from October until January as a donation to the local hunting club. (Not that we hunt, but the club with its strict rules provides a buffer during a 4-month stretch when we would otherwise have poachers entering the area.)

Last year, I got a fairly good swing blade and determined to cut a path along the creek, and then back eastward along the southern red line. It worked great! I was able all summer long to get all the way to the west end and back, in reasonable comfort. In the end, I found 23 new turtles, two of which I rediscovered before the end of the season.

This year I got a late start, but I've been gradually working my way westward. Here's a section before I swing bladed it (Goulding Creek is not visible at right, down a steep slope):

It's mostly six-weeks fescue (Vulpia octoflora) at this point, a native annual spring grass that over the next few weeks will die back and fall over. The evil Microstegium, already carpeting the ground below, will take its place, and it will get knee high and also thoroughly obscure the ground. The taller forbs are mostly crownbeard (Verbesina occidentalis), an attractive tall plant with yellow flowers. You in the West US will have seen this as a relative, V. encelioides. Ours is yellow, yours is golden.

And here's what it's like after swing blading. It's a little hard to tell, even though I waited a couple of days until the cut vegetation browned a bit. But I assure you I'm looking at a 4-5 foot wide cut. It's comfortable to walk through, the ground vegetation is just a few inches tall, and I can see well off to each side. I'm usually able to get a couple of hundred feet cut before I poop out. I figure I have two more days before I get to the west end.

Most of our heavy plant growth comes from April into June. After that there's a lot of die back, and summer grasses and forbs are less luxuriant in their growth. I'll have to do a little trimming in June or July just to keep the Microstegium down, but it's essentially done at this point, and well worth the effort.

Wednesday: 14 May 2014

View from Above  -  @ 16:27:15
It wouldn't be spring without mayapples, would it? Aren't they nice? These are doing great, and developing their fruits nicely. They cover the ground at the point on SBS Creek, and I'm always especially carefully how I walk here. Oddly, the population one ravine away to the west has (as it did last year) quite a rust infection, and is senescing at this point.

Oh, but what is that? Take a closer look.

This guy is only a couple of feet long, and probably it's the same copperhead I saw last fall, just a hundred feet upstream. Then, as today, it was right in my usual path, which would take me over that log in the background, and at that point.

You'll have to look even closer to see its head, which is raised - it was very much aware of my presence.

Yesterday, I ran across Reuben the box turtle, and after I did the usual photography, and weighing and linear measurements, I waited for him to come out of his shell, which he did fairly quickly. He's used to me by now, I guess.

He walked ahead a foot, and then stuck his head w a y up in the air and looked around. Then he moved another foot, and repeated the observation. I thought, that's how I walk.

And I do, except instead of looking up and around, I look down. Ten feet ahead, and then I move forward, looking around for box turtles. In the initial sweep, I set my brain on long and thin, and examine the ground ahead. Then, when I've walked the ten or so feet, I set it on round and domed, and look around. Apparently I can't see snakes if I'm thinking of turtles, and vice versa. I can do this for two or three hours, and then I'm exhausted. I may have only covered two miles, but the mental discipline is eventually tiring.

And rewarding, since that's why I didn't step on this guy.

Sunday: 4 May 2014

The Month of April  -  @ 13:42:51
It's The Month of April, Number 99 in a series. I've still only seen two box turtles (one dead), and attribute this to an odd occurence of extremely dry weather once temperatures have warmed up. Box turtles like warm and wet during the spring, but this just didn't really happen.


Here are the usual temperature anomalies products, at the National Weather Service Climate Prediction Center. Displayed are the mean temperature anomalies, not the absolute temperatures.

Click on the image for the high and low anomaly graphic on a new page:

Anomalies in temperature became much reduced in April. It was still considerably hotter in locations in the southwest, and continued quite a bit colder in Wisconsin and Minnesota, but extremes were much less widespread.

The southeastern states were a bit warmer in April, a switch from March. Most of the central US was just a degree or so cooler than normal, as was the Northeast US.

The National Weather Service Climate Prediction Center's precipitation plots are no longer being updated here. The closest I can find to the old familiar anomaly map is accessible from here. It seems a much less flexible and intuitive presentation, but maybe that's just me.

It's hard to compare the rainfall anomaly map in March with that in April, but it looks like much drier weather extended itself somewhat in the West (excluding Washington state). In contrast much of the eastern US received higher than normal rainfall, but there are certainly small regions that did not.

For the Athens, GA area:

Below is my usual daily rain/temperature plot visualizing the changes in temperatures and precipitation. The spiky lines are temperatures recorded roughly ten times a day, and the lighter blue columns are Wolfskin rainfall measurements. The black line is the 30-year average daily temperature, which is steadily moving upward as expected.

In April, as in March we had quite a fluctuation in temperatures - three extended instances of several days of warm, pleasant days. Those were punctuated with two short periods of colder than normal temperatures centered around periods of rainfall.

Here in the Athens area, we were somewhat above normal in temperatures in April. The Athens area mean temperature during April was a little less than one degree above the average 61.7F. We didn't break any record highs or lows, but did come within a degree of matching the cold record of 30F on April 16. It was just a couple of days after that the I found the dead box turtle.

We had 7 days more than 1 standard deviation above normal highs (average is 4.9 days). We had 4 nights with temperatures more than 1 standard deviation below normal lows (average is 5.3 nights). By these criteria, temperatures in April tended warmer.

The monthly histogram below shows the breakdown of high and low temperature range counts from April 1948 on. The error bars are just plus/minus one standard deviation, which I arbitrarily set as the limits outside of which are "significantly" anomalous.

Only the high temperature range of 80-89F had barely significant deviation above normal events in that temperature range. We had four extra days in that temperature range.

Below is the monthly accumulation of rain in Athens, GA. The river of peach is the long term standard deviation of all the daily black dots in the last 15 years, and the red line is the daily cumulative average. We're the green line this year, and for almost half the month it cradled that surplus of blue above the one standard deviation mark.

We had two significant periods of precitation in April, each contributing a couple of inches of rain, and elevating us briefly into the blue region of surplus. The average April rainfall is 3.15", and we had 4.17" in Athens and 4.77" out here in Wolfskin. We're still a bit below average for this time of the year, but April did help.

Prognosticator stuff:

What is the prognosticator telling us (as of April 29)?

The drought outlook over the next month and season is for continued dryness in the West, Southwest, and South west of the Mississippi. That could change, depending on the possible El Niño emergence.

In the east and southeast, we're scheduled for more rain over the next few weeks, subsiding into some kind of normal precipitation regime. Temperatures will be higher than normal for the first couple of weeks, and then picking up again a month or two down the way. The eastern US does not seem to be in danger of drought over the next three months.

ENSO stuff:

The folks at CPC have a version of PDF or HTML that is much different from their previous presentations, but at least it's there and the link isn't broken.

Not much change since the last summary. There has been a very large Kelvin wave that has preceded such El Niño events as 1982 and 1998, but surface temperatures in the Pacific have not risen above neutral levels yet. As of 28 April, ENSO neutral conditions continue, and are expected to remain neutral, now through the Northern Hemisphere spring. The planet has remained ENSO neutral now for 23 months. The last time we had such a lengthy period without an El Niño or La Niña must at this point have been in the 1990s.

(There continue to be signs that an El Niño may be gearing up for later in the summer. 50% chance is the likelihood, with a 10-20% chance that we'll have another La Niña.)

NOAA's Monthly State of the Climate product for March is available.

Summarizing from what I see on the map: Globally March 2014 was the fourth warmest ever recorded. The Arctic sea ice extent in March was the lowest recovery since satellite records began in 1979. Alaska had its third warmest three-month beginning of the year (behind 1981 and 2001). In contrast, much of North America, excepting the western US, experienced the coldest March since 2002.

Here is the final annual State of the Climate report for 2013 regionally, nationally, and globally. It's pretty US-centric, but there are comments for climate globally too.

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