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 |
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| 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 |
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|
Broomsedge |
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| Dewy web of a Lined Orbweaver Spider hung between grasses in the prairie Photo by Heather Larkin |
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|
Ramblers |
Shortly after entering the woods
on the Green Trail we noticed a dead tree with conspicuously spiraled wood.
 |
|
Aubrey |
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) |
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|
A Joro Spider in her |
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| Variegated Fritillary resting on a Southern Red Oak leaf Photo by Heather Larkin |
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|
Ants |
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.
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| 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 |
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| 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.
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|
Tall Goldenrod and Blue |
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|
Thanks to Avis, we now |
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| Grass-leaved Goldenaster Photo by Don Hunter |
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| 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