Turkey carving and muscle physiology. Prepare your dissection equipment, please.

Thanksgiving week promises many things, foremost among these delights are the physiology lessons offered by turkey carving.

The bird is presented to the world belly upward, as if in a dissecting dish. The carving knife scalpel slides through the skin, crossing feather tracts still visible as goose (really?) bumps, and cleaves a slice of pectoralis muscle. Who wants light meat? Then, after more blade-work, the femurs are dissociated from the pelvic girdle. Dark meat for anyone?

So many questions on one serving platter. Why the difference in color and taste? Are all birds this way? If we were to throttle then roast that insufferable Thanksgiving guest, would we have the same choice of meat cuts for our plates?

Turkeys are walkers. They fly only in short, plosive bursts. A startled turkey is a trebuchet of feathers. It twangs from the forest floor before smashing into the trees’ ramparts. The projectile moves fast — as much a forty miles per hour, I’m told — but has no staying power. Such bursts of power are delivered by “fast-twitch” muscle fibers that excel in anaerobic bursts, but then sag into exhaustion. Such muscles need relatively little oxygen and so their meat, when cooked, has none of the stain of blood or blood vessels.

Muscles in the legs are aerobic. They squeeze and pump all day without tiring. Such continual low-intensity activity requires “slow twitch” muscle fibers that are amply supplied with blood, capillaries, mitochondria, and oxygen-holding myoglobin. Under the knife: dark meat.

Turkeys are avian curiosities, though. Most other bird species use their wings for sustained flight and their legs for occasional strutting. In these species, therefore, the locations of dark and light meat are the reverse of the turkeys’ arrangement. A chickadee Thanksgiving would be instructive, although the meal would be short. From the roastlings’ chests we could carve slices of dark flight muscle, from the legs, the whiter meat.

As the breeders of industrial monstrosities know, most Americans prefer light meat to dark. By picking out the birds with the thickest and widest chest muscles, poultry scientists have bred varieties that by conforming to the desires of shoppers have lost the ability to grow to full adulthood without leg, lung, and wing problems. A pardoned turkey is not necessarily a lucky turkey.

And for that special Thanksgiving guest, the one whose boorishness or political rants add a spice of loathing to the table, remember that humans, too, have fast and slow twitch muscle fibers. Mostly, our muscles comprise a mix of the two, but the lower back and calf muscles are like turkey legs, always in use and so very dark. When the conversation reaches its nadir, such knowledge can provide a self-protective glaze of therapeutic imaginings.

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Creative writing assignments as glyphs

After my students turned in their latest assignment — a creative piece on “place” — I asked them to represent the form of their writing through a few wordless chalk marks on the board. They also summarized the main themes of content and form in a couple of sentences. This was improvised work: no preparation, go to the board and write.

The diversity of their subjects (what is “place”?) and the divergent ways in which they chose to represent the flow of their writing is intriguing and encouraging. I’m very pleased when I see a set of assignments that have emerged from the particularity of the students’ experiences, rather than from a template. Bring on the grading!

Click on any thumbnail image to scroll through examples of their work.

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Moon rising over an industrial park in Winchester, Tennessee.

starlings moon

Starlings: Come close, but stay away. The urge to flock, arrested at the last moment by beaks’ roving jabs, wings’ need to stretch.

Birded wires braided hundreds of meters of roadside. Within thirty minutes, the sun was down. The moon shed the season’s first frost onto metal, feather, and trash-strewn verge.



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David George Haskell:

Ah, the ginkgo’s gold returns. In their honor, I’m reposting this from a few years’ back. Long may the ginkgo continue to confound our naso-horticultural aesthetics.

Originally posted on Ramble:

The golden leaves of Ginkgo trees are just spectacular this week.

I have a special fondness for this species: its kin date back to the Permian (>250 million years ago), so the Paleozoic lives on right here on our campus lawns. The Ginkgo is also remarkably robust and is able to live in even the most polluted cities. Ginkgo trees were among the few living creatures to survive the horrors of the atomic bombs that were dropped onto Japan. Survivors, indeed.

In addition, the species refuses to conform to our narrow notions of botanical beauty. It is dioecious (female and males are separate individuals) and female trees are currently scattering their extremely pungent seeds all over tidy lawns (the smell is butyric acid — rancid butter). The philosophical underpinning of a lawn denies the realities of biology: death and sex are nowhere in evidence on a “nice” lawn. The Ginkgo violates these…

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Woodland family values: carrion beetles

Matt Schrader, my colleague in the Biology Department, keeps colonies of burying beetles in his lab. He studies the evolution of their behavior, especially the care that the parent beetles bestow on their young.

Nicrophorus beetles find small carrion — mice and birds — then bustle over the cadaver, preparing it for the young. Many species shave the corpse, some roll it into a ball, and a few chew then regurgitate the meat to their young. The growing beetles therefore live under the protection of their parents, an unusual arrangement among beetles, most of whom pass childhood without knowing solicitous parental care.

Nicrophorus tomentosus (the gold-necked carrion beetle) larvae on a mouse cadaver.

Nicrophorus tomentosus (the gold-necked carrion beetle) larvae on a mouse cadaver.

Other species, especially bacteria and fungi, also want to feast on the dead meat, so the parents paint the corpse with an antibacterial exudate. When threatened, the ooze also serves as a stinking defense mechanism.

Stay away...and have a free dose of antibiotics.

Stay away…and have a free dose of antibiotics.

Like other carrion beetles, Nicrophorus tomentosus have orange and black stripes across their wings. This is probably a warning signal to potential predators, like the bands on a poisonous caterpillar. Keep off, we taste bad. When the beetles take to the air, they reveal another signal: they sound and look like bumblebees in flight. Underwings are bright yellow and thrum just like a bee. Another layer of defense, perhaps?



Underwing yellow. The flight of the bumblebee, interpreted by a carrion beetle.

Underwing yellow. The flight of the bumblebee, interpreted by a carrion beetle.

Another moniker for these beetles is the “Sexton Beetle”: These animals are the caretakers of the forests’ graves, with more flashy garb than their human counterparts.

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Class exercise: Erasure poems from Kathleen Jamie’s “Findings”

This week I asked my students to create erasure poems from five chapters of Findings, Kathleen Jamie’s fabulous collection of essays on “the natural and unnatural world.” An erasure poem retains the words and word order of the original, and removes all but a small portion of the text. The task for the students, therefore, was to read the essay with close attention to the particularities of each word, while keeping an eye on how these words build into meanings and stories. The exercise is one more way of attending to a text, then using this attention to create new work. An inward movement, listening, then an outward gesture of response. We ended the class by reading the resulting poems aloud, with silence between readings. I found the readings particularly interesting and beautiful: hearing familiar and esteemed essays through the ears and minds of my students.

Click on the thumbnail images below to view a slideshow of the students’ work.

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Flocks of locally-grown red junglefowl arrive in McClurg Hall

Thanks to the work of University of the South Executive Chef Rick Wright, along with his colleagues, local foods are gracing our dining hall. This year, the University will use about 20% of the food-purchasing budget in the local farm economy, a flow of $300,000. A few years ago, that number was zero. Next year, we’re on track for 30%.

This Sunday, fried chicken, along with squash from the University farm, was on the menu, a celebration of the fall harvest. Thank you Chef Rick Wright, Farm Manager Carolyn Hoagland, and the many staff, students, and administrators whose work is reorienting campus dining away from the outlet pipe of the industrial food system and toward Tennessee’s fields.

2015-11-08 chicken 007 2015-11-08 chicken 010 2015-11-08 chicken 011

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Lit up

The Sewanee sky is often dark enough to see the silver smoke of the Milky Way drifting above the treetops. On other nights:

athletic field lights in cloudsClouds are ignited by light from dozens of pole-mounted bulbs around athletic fields. The pulse and swirl of light from the wind-driven clouds obscures all else. We vault the sky with our own glow.

Twenty percent of the world’s electricity is used for artificial lighting. In most countries, night lights are getting brighter and more abundant.

At the athletic field, no-one was on the turf. The pole-bulb clusters blazed on, regardless.

Come spring, robins will gather under the lights, singing their day-songs.

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Guest post: Callie Oldfield on roadside management of rare plants.

I’m reposting an article by Callie Oldfield, a former student of mine who now works in Sewanee’s Herbarium. She describes a new collaboration between the University’s Land Manager, Nate Wilson, Physical Plant Grounds Supervisor, William Shealy, and the state agency charged with “roadside maintenance.” Many interesting and rare plants grow in the open spaces along roadsides and under powerlines. Too often they are drenched in herbicide or pulverized by mowing before they can set seed. So I was delighted to hear of my colleagues’ work and very happy to learn that other states are interested in the results of their program. I’ll let Callie continue…

TDOT and Sewanee work together to protect endangered plants on Cumberland Plateau

by: Callie Oldfield — November 04, 2015

Domain Manager Nate Wilson and PPS Grounds Supervisor William Shealy help design new management practices to protect native and endangered wildflowers growing in road right of ways.

Sewanee and the Tennessee Department of Transportation (TDOT) have been working together to protect rare plants and native wildflowers that grow along roadsides in the Sewanee area. Typically, plants growing roadside are mowed and sprayed with broad spectrum herbicides in order to prevent their growth into the road area. These herbicides eliminate the trees that pose the greatest safety threat, but they can also kill forbs and herbs, including endangered species such as Cumberland rosinweed (Silphium brachiatum).

Cumberland rosinweed is a south Cumberland Plateau endemic in the daisy family. Cumberland rosinweed can be found along US Hwy 41A, which runs through the Domain and state-protected natural area Hawkin’s Cove; this natural area was acquired by the state in 1985 in order to preserve its habitat. Other rare and unusual plants that have been subject to right of way spray in the past include: eared goldenrod (Solidago auriculata), Morefield’s clematis (Clematis morefieldii), cylindrical blazing star (Liatris cylindracea) and cut leaf prairie dock (Silphium pinnatifidum).

Domain Manager Nate Wilson and PPS Grounds Supervisor William Shealy helped spearhead this initiative to protect native wildflowers through designing new management practices. Sewanee made two recommendations: First, to allow TDOT to go off of their road right of way and into roadside Sewanee property to prune trees in a more aesthetically pleasing way that also lessens the tree’s tendency to exhibit vigorous regrowth, and second, to design a new herbicide spray formula that targeted the problem woody species while promoting grasses, forbs, and wildflowers.

For 6 months, Nate worked with a TDOT botanist and a DOW Chemical Company representative to come up with a new herbicide formula that will target only trees, because “trees are the threat [to the roads], not the grasses or forbs we are trying to protect.” The new formula will deaden only the portion of the trees touched by the spray and prevent that part of the tree from producing leaves in the spring, but will not harm forbs or herbs. As a result, fewer trees will need to be chopped or mowed, and our endangered species and native wildflowers will be protected.

TDOT sprayed this herbicide in the Sewanee-area for the first time last month and is considering adopting the practice more widely in the future.

Photos courtesy of Mary Priestly.

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Who left all these twigs in the woods? 2015 is the year of girdled hickory.

Coleopteran work crews are trimming the forest canopy. Their leavings are scattered all over the leaf litter, in a profusion that I’ve never seen. Next spring’s hickory trees will therefore cast less shade and we’ll see the beetles’ legacy in a patchwork of sunlight. Canopy openings will admit more sky into the understory, fattening citrine spring-light with blues and reds.

The arborists are Oncideres cingulata, hickory twig-girdlers. The beetles’ bodies are stubby, just a half inch long, and their colors match the chestnut-ash blotching of hickory twigs. In late summer and autumn adults feed on the delicate bark of hickory twigs, chewing the soft phloem tissues through which the tree transports its sugars. These twigs also serve as mating sites, all-you-can-eat-buffets doubling as dating clubs.

Twigs then serve as nurseries. Females lay eggs under the bark, sometimes peppering a single twig with a dozen or more piercings. Then, the mothers go to work with their sharp mandibles, gnawing a ring around the twig. They start at the bark then, lathe-like, they rotate until the twig breaks away, leaving a few torn wood strands at the center of a clean cut. It is these shed twigs that are strewn everywhere. Lately I’ve seen one hundred or more on a short woodland walk.

Eggs hatch in late autumn and the larvae set to work within the fallen twigs, using symbiotic fungi to turn inedible wood into a paste of yum. In spring, when the weather has warmed, the larvae expand their activities, riddling the wood with tunnels. Beetle runnelling? They stay under the bark, emerging only to expel sawdust. In summer, the full-grown larvae gnaw small chambers into the twig, then curl up and pupate. The adults that emerges fly to the treetops to start on fresh twigs. Why the majority of this species’ life cycle is spent on the ground, inside fallen twigs, rather than on unfelled twigs, is a mystery. Perhaps the girdling shuts down the flow of defensive chemicals from the trees’ branches. The ground is warmer, too, giving the larvae more work days. Or woodpeckers may be less likely to drill the youngsters from fallen twigs than from standing branches. Whatever the reason, the stem litter underfoot evinces the beetles’ success.


I’ll put a girdle around the twig / In forty minutes ~ Oncideres puck

Bark scars: eggs below.

Bark scars: eggs are nestled below, inside the wood.

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