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March 29, 2020

Rolling Ants

From the New York Times:

These Ants Have a Revolutionary Escape Strategy

Why reinvent the wheel when you can become it?

Ants are bristling with defense weaponry.

Different species might sting their enemies, bite them with powerful jaws or shoot them with jets of formic acid.

Some even explode.

But Myrmecina graminicola — an ant about the size of a sesame seed — doesn't want to get into all that.

According to research published earlier this month in Scientific Reports, if one of these ants encounters danger while it's on a slope, it makes a practical choice: It tucks itself into a little ball and rolls away.

It is the only ant known to move in this way, and one of few rollers in the animal kingdom over all, said Donato Grasso, the paper's lead author and an ant ethologist at the University of Parma in Italy.

Dr. Grasso and his colleagues first spotted this unique behavior while scanning the forest floor during a trip to one of their field sites in Fornoli, Italy. (Many entomology discoveries are made this way: "When you are a biologist interested in insects, it is impossible not to look at the ground," Dr. Grasso said.)

The team found a few colonies of M. graminicola, which are so small and elusive they often go unnoticed.

When the insects were menaced by spiders and other ants, "they curled their bodies and disappeared" into the leaf litter, Dr. Grasso said. "They rolled away."

The research team decided to take some of the ants back to the lab.

It was difficult to find them, and when the researchers picked the ants up, they would sometimes somersault out of their hands.

But eventually, they caught some living inside fallen tree galls.

In the lab, the researchers used slow motion video to tease out the ants' choreography.

Roughly: A ready-to-roll ant tucks in its head and pulls its abdomen forward to form a ball.

It then lifts its legs up and tips itself forward to rest on its mandibles and antennae, which balance it like arms, Dr. Grasso said.

A final push with the hind legs, and it's off.

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On smoother surfaces like stones and leaves, the ants traveled at about 15 inches per second — about 80 times faster than their average walking speed.

They could move themselves about 6 inches, or about 50 body-lengths.

Such a distance is "pretty impressive," and shows that the ants' rolling form must be very efficient, said Nicholas Gravish, an engineer who studies ant locomotion at the University of California, San Diego and was not involved in the new research.

Dr. Grasso's team also set out to learn exactly what prompts the ants to make this unique exit.

They placed the ants on increasingly steep gradations, from zero degree all the way up to 90.

As the ants walked the slopes, the researchers exposed them to stressful stimuli.

The ants modulated their reactions depending on the context.

If they were on a relatively flat surface when the researchers bothered them, they simply froze.

But once the slope reached 10 degrees, some of the ants started to tumble away.

And at inclines above 25 degrees — about as steep as a beginner-level ski trail — all the ants tucked and rolled.

These and other tests show that "these ants behave this way only in specific circumstances," and that rolling wasn't a byproduct of other defenses like curling into a ball, Dr. Grasso said.

While humans enjoy assisted rolling, it is rare that other animals take part.

There are spiders that cartwheel across the desert, and some salamanders back-flip down boulders.

If you give a mother-of-pearl moth caterpillar a good poke, it will spin away like a little green coin.

But in nature, rolling is not nearly as popular a tactic as, say, running away.

It's also high-impact, which could be "catastrophic to larger animals," said Glenna Clifton, a scientist in Dr. Gravish's lab.

But if you can pull it off, it is effective.

In a later experiment, the researchers exposed M. graminicola to one of its enemies, a different ant species.

On flat ground, the M. graminicola casualty rate was 63 percent.

But when they tussled on a slope, it dropped to 10 percent.

"Fighting is not always the best way to survive," Dr. Grasso said. "Sometimes the best way is to escape."

More?

Below, the abstract of the paper.

Rolling away: a novel context-dependent escape behavior discovered in ants

For animals facing dangers, the best option to optimize costs and benefits of defense sometimes may be avoidance. Here we report the discovery of a peculiar strategy adopted by Myrmecina graminicola, a cryptic ant living in forest floor. Experiments showed that when disturbed these ants respond with immobility. However, upon perceiving disturbance but under specific inclinations of the substrate, they shift to an active escaping strategy: rolling away. This is a context-dependent behavior adopted only in appropriate circumstances. During rolling, the ants assume a ball-like shape using antennae and hind legs to obtain an active movement along a stable trajectory. Finally, we assessed the adaptive value of this strategy measuring its effectiveness in defense against enemies. This is the first example of locomotion by rolling discovered in ants and one of the very few among animals, offering opportunities for multidisciplinary research on the adaptations and biomechanics underlying it.

March 29, 2020 at 04:01 PM | Permalink | Comments (0)

Thinking Red — Amy Clampitt

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Swamp maples' unmasked sugars'
underhue, intense as madder,
alizarin or cochineal (a dyestuff

steamed from heaped corpses of an insect
native to Mexico: such the odd lore
of commerce in the exotic a bemused

E. Dickinson took note of): to
grub it out, the sense of it, down
to the madder's fraying final foothold,

the capillaries' threadily
untidy two–way form of discourse;
T. Hardy's ruddleman trundling

his dyeload of ocher; or
the bog–dwelling sanguinary
pitcher plant whose drowning dens

decoct a summer soup of insects
whose mainstay in turn is gore:
the clotted winter melancholy

of the sumac; hawthorn encrimsoned,
dogwood beaded the adorning
pigment of survival; the eyeball's globed,

dendritic riddle: to unencode
the hematite, the iron in the granite,
the carmine in the carapace, one has

to try to think in wavelengths. Light
has, we're told—I have it from G.
Wald—certain properties of waves

but also of particles. That's very
strange: G. Wald again.
Mind stuff, he tells us: physical

reality is mind stuff. In creatures
that puzzle over what it is, he says,
the universe begins to know itself.

Is this good news? I hope so. It's
that holdout, put–upon, reluctant
red (I think) that raises half a doubt.
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March 29, 2020 at 02:01 PM | Permalink | Comments (0)

County-by-County Social Distancing Map of the U.S.

Screen Shot 2020-03-28 at 3.33.12 PM

From the Washington Post:

If you have a smartphone, you're probably contributing to a massive coronavirus surveillance system.

And it's revealing where Americans have — and haven't — been practicing social distancing.

On Tuesday, a company called Unacast that collects and analyzes phone GPS location data launched a "Social Distancing Scoreboard" that grades, county by county, which residents are changing behavior at the urging of health officials.

It uses the reduction in the total distance we travel as a rough index for whether we're staying put at home.

Comparing the nation’s mass movements from March 20 to an average Friday, Washington, D.C., gets an A, while Wyoming as a whole earns an F.

How do they know that?

Efforts to track public health during the coronavirus pandemic are a reminder of the many ways phones reveal our personal lives, both as individuals and in the aggregate.

Unacast's location data comes from games, shopping and utility apps that tens of millions of Americans have installed on their phones — information the company normally analyzes for retailers, real estate firms and marketers.

It's part of a shadowy world of location tracking that consumers often have little idea is going on.

There's no evidence that the U.S. government is using phones to enforce stay-at-home orders or track patients.

But privacy is often the first civil right on the chopping block when public health and national security are at risk.

Getting the balance right is hard.

South Korea has used an app to track tens of thousands of quarantined people whose phones would alert authorities if they left home.

Unacast, a small start-up, assigns letter grades to counties and states based on how much residents have changed their movements on a specific date compared to what's typical on that day of the week.

If many people in an area used to commute daily to work but now are leaving the house only for visits to the grocery store, the data would show a big reduction in travel distance.

The Unacast maps are searchable and will be updated daily. 

Unacast assigned an A grade to places that show at least a 40 percent decrease in average distance traveled.

On March 20, the first day in its database, the states as a whole that earned an A included Alaska, Massachusetts, Nevada and Vermont.

Big reductions in movement are also visible in areas hit hard by the virus, such as New York City (a 57 percent change) and California’s Santa Clara county (a 54 percent change).

Unacast deemed anything less than a 10 percent change an F: Only Wyoming earned that grade.

Albemarle County in Virginia,

2

where I live,

3

gets a gold star.

March 29, 2020 at 12:01 PM | Permalink | Comments (1)

Siesta

March 29, 2020 at 10:01 AM | Permalink | Comments (0)

Snapperz

Snapperz

From the website:

Snapperz is a simple fidget toy that will suck you in... literally.

The silicone square contains two suction cups that oppose each other.

Give it a squeeze and they'll stick together.

Release your grip, and they'll pop apart, making a superb snapping sound.

The delightfully simple toy can be popped again and again as you find yourself lured in by the siren call of the satisfying snap.

2.25" x 2.25" x 0.75".

Note: Because we receive this item in an assortment of colors, we must sell them randomly. You'll receive purple, light blue, royal blue, magenta, lime, or orange.

Still not convinced?

Watch 

the video.

$4.99.

March 29, 2020 at 08:01 AM | Permalink | Comments (0)

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