Wednesday, August 26, 2020

Raven's Renditions

 

by

Tim Homan       

       Summer 1988, Canyonlands National Park*, southern Utah's redrock and hoodoo country.  Wingate Sandstone, Chinle Formation, Moenkopi Formation, White Rim Sandstone: a geologic layer cake from the Permian, the Triassic, and the Jurassic, each band with a distinct composition, age profile, and color that changes with the light.
        Page and I arrived at the small primitive campground (Willow Flat in the park's Island in the Sky district) late in the afternoon, the day cloudy and surprisingly cool, and staked out our tent, a dinky two-person dome.  We are both in the tent, resting from the three-day drive.  I am flat on my back and moaning intermittently from unaccustomed chest pains: a fast pulse with some sort of arrhythmia, painful and thudding, at a ratio of one squirrely misfire every five or six quick beats.  The pain is not heart-attack severe, not excruciating, but damned inconvenient and disconcerting nevertheless.

Monday, August 24, 2020

FINE Things No. 9

 I've been enjoying the butterflies this summer and that prompted me to share two quotations with you. The first is via Dac Crossley and is by the poet Rabindranath Tagore:
 
The butterfly counts not months but moments, and has time enough.
 
The second is by the Chinese philosopher Lao Tzu:
 
What the caterpillar calls the end, the rest of the world calls a butterfly.

Here are this weeks FINE Things:

Keeping with the butterfly theme, one species, the Large Blue, had been extinct in Britain for 150 years. Recently it has been restored and the story demonstrates that you can't just plop a species down and expect it to survive.
 
We think of the caterpillars of moths and butterflies as committed herbivores. But, here in eastern NA, there is a carnivorous butterfly known as the Harvester. The caterpillar feeds on aphids. It's the only carnivorous caterpillar known in the continental US. But in Hawaii there are numerous species of carnivorous moth caterpillars in the genus Eupithecia. You can read about them here and see one in action here.

750 Million GM mosquitoes will be released in the Florida Keys.
 
 
The gardeners among you probably already know this, but a New Yorker article advocates The therapeutic power of gardening.

With future population growth plus climate change we can expect food security to become more and more important. We'll not only have to change our current crops to adapt to new conditions, we'll have to change the things we eat. Perennial vegetables may play a role in this adaptation. A recent study surveys these vegetables and is reported on in this article:
Perennial Vegetables Are a Solution in the Fight Against Hunger and Climate Change

The world is a muddy place, but it wasn't always that way. Knowable magazine explores The Origin of Mud. "For most of Earth's history, hardly any of the mucky stuff existed on land. It finally started piling up around 458 million years ago, changing life on the planet forever."

Most ramblers will remember that many of the spring wild flowers produce seeds with nutritious "handles" (called elaiosomes) that attract ants. The ants carry the seeds to their nest, feed the elaiosome to their larvae and discard the seed. That much is known. A virtual Ecological Society of America meeting this month updated our knowledge of this ant-plant symbiosis. It is beautifully summarized by science writer Elizabeth Pennisi in this very accessible article.

That's all for this week.
Dale

Sunday, August 23, 2020

Wandering Caterpillars

 
An Orange-striped Oakworm, Anisota senatoria, caterpillar. The grid marks measure 1/4 inch.
(photo by Dale Hoyt, 8/22/2020)
From late summer through fall you will often see caterpillars crossing sidewalks or streets. One commonly encountered species is the Orange-striped Oakworm (Anisota senatoria). It is black with several yellow or orange longitudinal stripes. (Or is it orange or yellow with black stripes?). Its other prominent feature is a pair of flexible "horns" that arise from the second segment behind the head.
Shorter horns are found on the other body segments. 
Orange-striped Oakworm caterpillar nibbling around a gall on a Water Oak leaf.
(photo 8/26/2020; Emily Carr)
   
 
The caterpillars eat oak leaves, mainly in the red oak group. 

Leaves being stripped by Orange-striped Oakworms.
How many caterpillars can you find?
(photo 8/26/2020; Emily Carr)
  
When they have reached the right size they go wandering, looking for a suitable place to burrow into the soil. They excavate a chamber where they will spend the winter in the pupal stage. The moth emerges the following spring.
As caterpillars feed they grow in size and periodically shed their skin, a process called molting. In most butterflies and moths the caterpillar molts five times, the last molt resulting in the pupal stage. With each successive molt the caterpillar not only increases in size, it may change its behavior and/or appearance. The newly hatched oakworms are gregarious -- they feed together on the oak leaves. As they grow and shed their skins they become more solitary, dispersing over their host plant. Their coloration also changes. This species has a single generation per year.


Wednesday, August 19, 2020

Where the Creek Turkey Tracks: Wild Land and Language

 by

Tim Homan

        In the mid-to-late 1970s, when I began exploring the mountains of North Georgia, written directions to trailheads were often short, cryptic, and inaccurate.  In general, directions, trailhead signage, and parking areas were all primitive by today's standards.  Back then, a trail was often more difficult to find than to follow.  In part, those problems led to my decision to write a guide that would include easily understood and accurate directions to the trailheads.

Beech Nuts

 


American Beech fruit
The husk of the fruit is covered with spines and divided into four lobes.
Each fruit contains 2 or 3 seeds.
(photo by Don Hunter)



 

Opened American Beech fruit showing the four husk lobes and two three-sided nuts.
The grid lines are 1/4 inch apart.
(photo by Dale Hoyt)



 

American Beech begins to produce fruit at the age of 40 and hits its stride at age 60. That might seem ancient in human terms, but a tree can live 300 to 400 years.

American Beech has another way of reproducing: root suckering. The shoots that are produced are, of course, genetically identical with the tree that produced them. The tendency to produce these off shoots varies geographically. It is more common in the north and at higher elevations in the Appalachians. Trees growing in lower elevations, coastal plains and in the piedmont tend to produce more seeds and fewer root suckers.

When talking to people of a certain age about Beech trees the subject of Beech-Nut Gum generally comes up: "Was it really made from Beech nuts?" As far as I've been able to determine, Beech-Nut Gum is no longer made. Wikipedia tells us that the company that made the gum started out as a ham- and bacon-producing enterprise in 1891, known as Beech-Nut Packing Company. Perhaps their hogs were fed beech nuts the way some hogs are fed on acorns? It was a common practice, back in the day, to turn hogs loose in the woods to find their own food. That food, called "mast," consisted mostly of acorns and beech nuts. For the old timers and the edification of those who do not remember Beech-Nut Gum, here is a commercial that you might remember. (You may have to wait for a political ad to play before the commercial.) The name seems to be more a brand than a reference to the contents of a product. The internet has pictures of Beech-Nut Baby Food and Beech-Nut peanut butter.

The other context that most people associate with "Beech" is in Budweiser beer: "Beechwood aged." For me, this conjured up row after row of large barrels made from the wood of American Beech trees. Once again, the imagination doesn't match the reality. Consult this website for the full story.


 

FINE Things No 8

 FINE = Fun, Interesting, Novel, Exciting

Cranefly Orchids, Tipularia discolor, are blooming in woods near you.
(photo by Catherine Chastain}


Linda says: The Great Georgia Pollinator Census is this week, August 21, 22. It is a wonderful opportunity to participate in citizen science! Details available here.
 

The unique faunas of islands all over the world suffer from invasive predators like rats. New Zealand has decided to get rid of these rats and other invasive predators to preserve their native birds.

This video from Knowable Magazine explains the difference between Locusts and Grasshoppers and shows locust swarms in current day Africa.

Swarms of migratory locusts regularly devastate crops across the world, but why these swarms form has been a mystery. Now, a team of researchers have identified a pheromone that causes solitary locusts to come together and form flocks that number in the billions. (A pheromone is a volatile chemical, an odor, that causes a change in the behavior or physiology of another individual.) Find out how this pheromone was discovered and how this knowledge could lead to preventing locust swarms.

Emily recommends "The Pleasures of Moth-Watching."

Milkweeds are protected from many herbivores because they carry a poison, but some insects, like the Monarch butterfly, can eat milkweed leaves. How they are able to do this is an interesting evolutionary story

Jan Coyne suggested this article from the NYT: A Honeybee's Tongue Is More Swiss Army Knife Than Ladle.

That's it for this week. 

Dale



 


 

Wednesday, August 12, 2020

FINE Things No 7

 FINE = Fun, Interesting, Novel, Exciting

About box turtles.

Helen Macdonald in the NYT Magazine: The Mysterious Life of Birds Who Never Come Down. It's about Swifts; by the author of H is for Hawk.
 

Freshwater mussels; an overview with videos from Knowable Magazine.
 

I posted about freshwater mussels earlier this year.
 

This article talks about freshwater mussel's role in stream ecology and current restoration efforts.
 

Catherine Chastain recommends this article about mosses that use quartz parasols. 

Comic book: Centuries of pondering - and squabbling about - trees

Until next week,

Dale


Box Turtle

Yesterday, on our daily walk in the neighborhood, we found this strikingly patterned turtle in the middle of the road. It's a male Eastern Box Turtle, Terrapene carolina.

Male Eastern Box Turtle, Terrapene carolina
 

The symmetrical orange markings in the middle of the upper shell are each in a separate scute. Each scute is a bony plate covered by a horny epidermis. As the turtle grows the scutes expand at the edges and the epidermis keeps pace with this growth, producing a ring on the margin of the scute. These rings of epidermis  accumulate, one per year, and produce a "tree ring" like effect. You can clearly see the edges of each ring on the large scutes. Try to count them -- the number of rings indicates the approximate age of the turtle. Approximate because, as the turtle ages, the older epidermis rubs off causing a ring to disappear, so counting the scute rings is an under-estimate of the age. (I could make out somewhere between 10 and 15 rings on the scutes in the middle of the back. Did you get more or less?) So, conservatively, the turtle was between 10 and 15 years old. The shell was approximately 8 inches in length.

How did I know this is a male turtle? The lower shell, that covers the belly of the turtle, holds the secret. It is either flat or has a concave depression toward the tail half of the shell. If the depression is flat, the turtle is a female. Males have the depression.

Lower shell of box turtle showing the depression typical of male turtles.

 

The photo above shows the underside of the box turtle. I hope you can make out the depression just to the right of the darker, damp area. Why would a male turtle have this depression? When turtles mate the curve of the female shell fits into the male shell depression, facilitating reproduction.

We moved the turtle off the road and released it in a more heavily vegetated area. 

Box turtles have a diet that includes fungi, earthworms, fruits, and green leaves; in short, almost anything they can catch or reach. They appear to be major dispersers of Mayapple seeds. The turtle eats the fruit and, some distance away, defecates the unharmed seeds.

 

 

Wednesday, August 5, 2020

Fine Things No 6

FINE = Fun, Interesting, Novel, Exciting

The best way to control the spread of virus on a college campus.

Satellite photos and what they can tell us about  Earth's vegetation.

Many vines use tendrils to assist their upward climb toward the light. The tendrils wrap around the supports they encounter and then the tendril coils up, pulling to plant toward its support. Here is how the cucumber tendril manages to coil, along with a cool video.

Some South American lizards that live at high elevations can freeze solid and recover!

There Are Two Ways Out of a Frog. This Beetle Chose the Back Door.

Until next week,
Dale



A Gift of Wild Beauty and Grace

 by Tim Homan
  
        Crags Campground, Lassen Volcanic National Park*.  The end of June in 2014 and the next to last night of a long camping trip to northernmost Arizona and California.
        After hiking and touring from early morning to mid-afternoon, Page and I returned to camp for rest and a little reading.  During the early evening we sat together on the picnic table-talking softly, writing in our trip journals, and planning the next day's hike.  We wrote entries for a new aquatic chick sighting.  While walking around a scenic front-country lake, Manzanita, we were treated to good looks, especially close on several occasions, at the fuzzy and fluffy young of the Pied-billed Grebe for the first time ever.  The greblings were tricked out in black-and-white stripes above the waterline.  Their eyes and the bases of their bills were ringed in yellow.  An intermittent halo of orange-red crowned their heads with an additional flourish of color.