Ramble Report October 6, 2022

Leader for today's Ramble: Linda 

Authors of today’s Ramble report: Linda. Comments, edits, and suggestions for the report can be sent to Linda at Lchafin@uga.edu. 

Insect identifications: Heather Larkin, Bill Sheehan, Don Hunter

Number of Ramblers today: 28

Today's emphasis: Seeking what we find in grasslands and forests

 Reading: From “Mozart’s Starling” by Lyanda L. Haupt (pp. 170-171)

In 2012 an international consortium of prominent scientists signed a document called “The Cambridge Declaration on Consciousness” in which they proclaimed that animals, from birds to mammals to octopuses, possess consciousness similar to humans’… But do most of us really need a scientific document to inform us that the animals we live with are conscious beings?

I believe that the human sense of connection with the more-than-human world is innate – and joyous. It is our truest way of being, of dwelling, of relating. It is not new; it is very old. It surfaces in the art and culture of every civilization across place and time – in stories of human-animal relationships that are based on respect, awareness, knowledge, and love.  

I have no desire to confer on any animal a capacity that it doesn’t have. There is no need. Animals have capacities enough – those we do understand, those we do not yet know, those we can never know because they reside in the unique minds of other-than-human beings. Starlings gather knowledge of their world by gaping; parrots learn with their tongues, raccoons with the sensitive pads on the palms of their front paws, earthworms with their shining skins. “We live in the lap of immense intelligence,” wrote Emerson, “which makes us receivers of its truth.” And to me, this is the beauty of [scientific work on consciousness] … It reminds us of the creative awareness, at once scientific and poetic, that we stand on a continuum of life. That we are part and parcel, along with every creature that crosses our path, of a fierce and beautiful intelligence.

(Other highly recommended books by Haupt are "Crow Planet" and "An Urban Bestiary.")

Show and Tell:

Bill brought the egg case of a Chinese Praying Mantis, a large mantis that was accidentally introduced from China in the 1890s but is now widely sold for insect control and also as a household pet(!). They have been observed eating reptiles, amphibians, and even young hummingbirds. The adults are up to five inches long, nearly twice as large as our native Carolina Mantis, and seriously outcompete the natives. The female lays her eggs on a twig or other structure and extrudes a frothy substance that encloses the eggs. The froth hardens into a tan, more or less spherical crust that protects the egg over the winter. In the spring, all the young hatch at the same time; any that linger are eaten by their peers. One source recommends crushing the egg cases, freezing them for a week, or submerging them in water as a form of controlling this invasive species.

Chinese Praying Mantis egg case
Photo by Linda Chafin

Chinese Praying Mantis are brown with a green stripe.
Photo by Luc Viatour

Carolina Praying Mantis are about 2.5 inches long and brown and gray. Their egg cases are composed of the same foamy material but are flattened and oblong.

Carolina Praying Mantis adult (left), photo by Kaldari
Carolina Praying Mantis egg case (right), photo by Tom Porterfield

 

Announcements/Interesting Things to Note:

The Botanical Garden’s Native Plant Sale is continuing for its final three days, Thursday–Saturday, October 14-16. The sale takes place at the greenhouses at the Mimsie Lanier Center for Native Plants.

An invitation from Jenny Cruse-Sanders, Director, State Botanical Garden of Georgia... Dear Friends, Ramblers, Staff and Faculty:  I am writing to invite you to participate in a charrette for concept designs for a natural area master plan for the State Botanical Garden. This charrette is for anyone who has not been able to participate during previous charrettes. Please join us this Wednesday, October 12, from 2:00 to 4:00 pm. The charrette will be held in the Porcelain Museum classroom. Your input is important to this process. Please feel free to share this invitation with anyone who has not had a chance to join a charrette. Thank you in advance for your participation on this effort! Jenny

The Ugarden Student Farmer’s Market will continue every Thursday, 4:30-6:00 pm, until Thanksgiving (and possibly the week after). 2510 South Milledge Avenue – first paved drive on the right after the entrance to the Botanical Garden. 

Today's Route: We bypassed the Shade and Dunson Gardens today and headed across the road and onto the White Trail Spur that crosses the prairie. From there we walked up the White Trail to the top of the ridge, and took a left on the old dirt road till we reached the Green Trail. We turned left there and returned through the prairie and via the road to the Visitor Center.

OBSERVATIONS:

As we crossed the prairie on the White Trail, we noticed that two late-blooming species of grass are beginning to flower: Broomsedge and Split Beard Bluestem. They are in the same genus (Andropogon) and, from a distance, especially when looking across a copper-colored grassland in midwinter, they look pretty similar. Up close, Broomsedge's hairy spikelets are held in a cluster that has leaves below it and a spathe enclosing it. Splitbeard Bluestem spikelets are held at the top of a slender, leafless stalk, and split in two when mature. 

Splitbeard spikelets are held at the tip of a leafless stalk.
Photo by Don Hunter

Broomsedge spikelets are partially enclosed
by a leaf-like bract called a spathe.

Dewy web of a Lined Orbweaver Spider
hung between grasses in the prairie
Photo by Heather Larkin

 

Ramblers entering the woods
on the west side of the prairie
Photo by Heather Larkin

Shortly after entering the woods on the Green Trail we noticed a dead tree with conspicuously spiraled wood.

Aubrey and Liz examine the spiraling grain of the wood on a dead tree.
Photo by Linda Chafin

In some trees, the grain spirals around the trunk rather than going straight up and down. The cause, or causes, of this has been studied for many decades, and there are several hypothesis about Why (function of spiral grain) and How (mechanism of spiraling) it happens.

Why it happens seems to be the easier question to address; there are several good theories.

Spiraled grain may confer protection from wind storms, which stress tree trunks and may pull apart the layers of wood in the interior of the tree. If the grain spirals in the same direction as the wind, the layers are less likely to be torn apart. Many spiral-grain trees change directions over time, reversing the spiral from left-hand to right-hand and back again. This may make the tree stronger over time and able to withstand wind from all directions.

Spiraled grain may occur when a tree is growing in an environment where water and nutrients are hard to obtain. In a tree whose roots are located near water but the trunk has grown in a different direction toward the sun, the spiraled vessels may more efficiently convey water and nutrients throughout the entire tree.

Spiraled grain occurs to some extent in all trees, including those not living in harsh conditions. All trees have somewhat asymmetrical crowns, with the side facing the sun being larger. Combined with prevailing winds, this could produce spiraled grain. Some researchers have argued that trees in the northern hemisphere typically have a right-handed spiral, while trees in the southern hemisphere typically have a left-handed spiral, providing support to the prevailing wind theory.

How it happens is harder to explain and has not been as well researched. Tree trunks and branches are enclosed by a cylinder of cells (the cambium layer) that divide inwardly to produce wood, and outwardly to produce bark. This cell division is responsible for the increase in a tree’s girth. The newly produced wood cells are stacked vertically on top of each other, forming a tube, with perforations in the cell walls that allow water and minerals from the soil to be carried upward, and carbohydrates from photosynthesis to be carried downward. How these newly produced cells are induced to grow off the vertical is the big question, and the answer seems to boil down to stress, such as wind and snow-loading, being applied to the cells as they mature. If you would like copies of articles that go into tremendous detail about spiral grain, send me an email.

 

This week’s Ramble was originally planned to focus on fungi, but the many dry weeks we’ve had in September and October put paid to that – there are simply no fungi to be seen. Instead, we rambled the White and Green trails, enjoying the perfect temperatures and clear light of autumn in the Piedmont. Thanks to Heather’s keen eye, we enjoyed several insect finds. 

Left, Laugher Moth caterpillar (photo by Heather Larkin)
Right, Laugher Moth adult (photo by Richard Crook)

 

A Joro Spider in her disorganized web
Photo by Heather Larkin

Variegated Fritillary resting on a Southern Red Oak leaf
Photo by Heather Larkin

Ants “farming” aphids on a Southern Red Oak Leaf
Photo by Heather Larkin

 

Here’s a nice summary of the relationship between ants and aphids from a McGill University website:

“Several species of ants have a special symbiotic relationship with aphids–they farm them! Aphids feed primarily on the sap from plants and secrete a liquid called honeydew. This secretion is very sugar-rich, and quite favored by ants as a food source. As a result, a system has been hashed out by these insects wherein the ants herd the aphids around to the juiciest parts of plants, protect them from predators, and carry them into their nests at night and for winter. In return they are allowed to ‘milk’ the aphids- stroking the aphids with their antennae, coaxing them to secrete their honeydew which is then lapped up by the ant. In every species of ants, workers will specialize in different roles such as nursing or foraging to fulfill the needs of the colony – in farming ants, some workers will specialize just in shepherding and caring for the aphids! There's even some evidence that ants build pastures of a sort, to keep their herded aphids in. When the colony departs one nest site to form another at a new location, they will carry an aphid egg with them, to establish a new herd and maintain their resources.”

Tim inspects the bark on a Shagbark Hickory.
Photo by Linda Chafin

 

Hickories are at least as common as oaks in the Garden’s Piedmont Oak-Hickory Forest. Two species, Mockernut and Pignut, are abundant throughout on moist to dry slopes, and Sand Hickory is limited to the driest ridges and slopes. A fourth species, Shagbark Hickory, is rare at the Garden, found only in the area that is underlain by amphibolite, a type of bedrock that raises the pH of the soil that develops over it. The amphibolite area lies between the White and Green trails and extends both northeast across the prairie and southwest to the river. It includes a number of calciphiles – plants that favor circumneutral or basic soils – such as Shagbark Hickory. So far, we’ve found only four Shagbarks and are very fond of all them.

 

Both Shagbark Hickory and White Oak have "shaggy" bark. Their leaves are quite different: Hickories have compound leaves, oaks have simple leaves. But the bark can be confusing. The difference lies in how the strips of bark pull away from the trunk.

Plates or strips of Shagbark Hickory bark are attached to the trunk in the middle while the ends of the strips lift away from the trunk.
Photos by Don Hunter

Strips of White Oak bark lift away from the trunk
along the side of the vertical edges.
Photo by Don Hunter

 

Returning to the Visitor Center, we enjoyed a late flush of wildflowers and fruits in the prairie and along the road. 

 

Tall Goldenrod and Blue Mistflower
Photo by Linda Chafin

Thanks to Avis, we now know that Rabbit Tobacco (aka Sweet Everlasting) flower heads smell like maple syrup when crushed.
Photo by Linda Chafin

Grass-leaved Goldenaster
Photo by Don Hunter

Passionflower fruits on the Dunson Garden fence
Photo by Linda Chafin

  

Postscript: Watch this video for a surprising answer to the eternal question: how do snakes drink water? Thanks to Jan Coyne for sending this link!

 

OBSERVED SPECIES:

Chinese Praying Mantis        Tenodera sinensis

Carolina Praying Mantis        Stagmomantis carolina

Broomsedge Grass               Andropogon virginicus

Split Beard Bluestem             Andropogon ternarius

Lined Orbweaver Spider       Mangora gibberosa

Dog-fennel                             Eupatorium capillifolium

Laugher Moth                         Charadra deridens

Joro Spider                             Trichonephila clavata

Variegated Fritillary                Euptoieta claudia

Southern Red Oak                 Quercus falcata

Mockernut Hickory                Carya tomentosa

Pignut Hickory                       Carya glabra

Shagbark Hickory                  Carya ovata

Tall Goldenrod                       Solidago altissima

Blue Mistflower                      Conoclinium coelestinum

Rabbit Tobacco, Sweet Everlasting       Pseudognaphalium obtusifolium

Grass-leaved Goldenaster    Pityopsis graminifolia

Passionflower                        Passiflora incarnata

Gulf Fritillary                           Agraulis vanillae