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\input fmt/com.h
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{\title Antlion Herding Patterns with Interrupted Communication
Pathways}
\vfil
Holden Rohrer and Radeen Abree, Centennial High School, Roswell,
Georgia, US.
\vfil}\hfil&\cr\tabrule
&%#1
\vskip1pt
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\hangindent=1.55in\hangafter=-1\parindent0pt
\noindent{\bf Rationale:}\par
\hangindent=1.55in\hangafter=-5\parindent0pt
\input src/rationale.i
\input src/hypo2.i
&&%#3
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\line{\hfil\vbox{\picturetop{graph/boxplot.png}{This boxplot
illustrates the nearest neighbor metric on different trial sizes and
interventions. The artificial pits trials showed the largest impact
on the metric, indicating antlions choose settlement based on
surrounding pits.}{\wid}}\hfil
\hbox{\picturetop{imgs/obstacles-24x24.png}{Voronoi diagrams show
territory that is nearest to a given pit. Blue dots represent pits, and
colored shapes represent obstructions.}{\wid}}\hfil
\hbox{\picturetop{imgs/trails-24x24.png}{Trail erasure did not
interrupt, and may have reinforced, the regularized pattern
antlions make. Food-catching regions are well-distributed
between pits in all trials.}{\wid}\hfil}}%
\vfil
\line{\hfil\stats{Pit depths and widths remained fairly constant
between trials. The nearest-neighbor metric also remained constant,
but only within trial sizes. This indicates antlions respond to
their environmental restrictions.}\hfil}%
\vfil
&\cr\tabrule
&%#2
\smallskip
\advance\ct by 1\pre{\number\ct.} 24 16oz deli containers were acquired and 1 antlion was placed in each
\li The sand (100lbs) was uniformly spread into a $24"\times24"$ plastic container
\li Marks were made on the box so the pits’ locations could be observed.
\li Each trial was started by introducing a constant number of antlions, at the same time
\li After the first and second days of each two-day trial, the coordinate locations, diameters, and depths of each antlion pit were recorded for analysis.
\li After each trial, all living antlions were restored to their pits and dead antlions disposed of.
\li Further trials repeated these same protocols except with space
restrictions of $24"\times24"$ and $12"\times12"$ and three
disruption methods:
\leftskip.3in
\lli ``Trail erasure'' included brushing away old trails in the
sand that antlions have dugout, in an effort to determine if the
antlions are reliant upon the presence of trials or pheromones
when distributing.
\lli ``Fake pits'' were introduced to mimic an antlion pit, in
order to determine if antlions were dependent on the presence of
surrounding pits.
\lli ``Artificial obstacles'' included the introduction of rocks
to determine if antlions are aware of the shape of their
settlement region and use that to organize the group.
\smallskip
&&%#4
\smallskip
This experiment investigated how antlions make individual settlement
choices, and how those choices create group patterns.
Environmental factors, in terms of other pits, trails, and environment
shape were investigated.
Antlion larvae were shown to regularly, rather than randomly, distribute
themselves, indicating they avoid other pits and respond to
environmental structure.
As also observed in the previous study, antlions use behaviors like
this, cannibalism, and reclusivity as mechanisms to limit intra-species
competition.
These behaviors increase species fitness and therefore are an
evolutionary advantage.
Avoidance mechanisms can be extended to the analysis of other animals
and engineering applications.
Bottom-up organization often relies on a hierarchical image of its
members, like a hexagonal or rectangular grid, but individuals don't
require strict communication pathways for efficient, semi-regular
distributions such as an antlion's.
The distribution patterns of the antlions can also be expanded to
understand similar organisms, such as termites, ant, bees, and wasps, as
these animals also distribute as groups.
Similar behaviors may be used to draw conclusions regarding the
evolutionary history of these organisms.
\smallskip
&\cr\tabrule}
\bye
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