CURRENT LAB MEMBERS
Ingi Agnarsson, Postdoctoral
Scholar, Ph.D. 2004 George Washington Univ.
Ingi is trained in the
systematics and evolution of spiders, particularly spiders that express
cooperative web spinning and prey capture behaviors. More generally,
Ingi's research interests span shore ecology, morphology, taxonomy,
biodiversity, sociality, inbreeding and phylogenetic theory. His work in
the lab focuses on the evolution of silk biomechanics in orb-weaving
spiders. You
can find out more about Ingi's research at this link.
Cecilia Boutry, Ph.D. Integrative Bioscience, began
spring 2006
Cecilia is studying how individual level plasticity in the mechanical
performance of spider silk is related to variation in web architecture
and the environment. She is particularly interested in testing the
hypothesis that spiders can actively control the structural and material
properties of silk. Cecilia is also interested in relating variation in
silk performance to functional differences between webs during prey
capture. Cecilia has degrees in Biology from
Université des
Sciences et Technologies de Lille and from
Université
François-Rabelais Tours.
 Andrew Wu, M.Sc. Biology, began fall 2006
Andrew's interests are in community and ecosystem level ecology. He
is currently investigating how web-spinning
spiders influence plant-pollinator interactions. Andrew earned his B.S. in Wildlife Biology from the
University of Alaska Fairbanks.
Our current undergraduate
research assistants are Chad Rooks (Psychology), Taylor Gondek
(Biology), and Rachel Stevenson (a post-bac. student).
Our summer 2007 undergraduate
research assistants were Jaclyn Stenger (from
Xavier University), Marlena
Abraham (UA), and Sarah Anderson (UA)
LAB ALUMNI
Raphael Royaute, visiting
researcher summer 2007
 Raphael
came to UA from Ecole
Nationale Supérieure d’Agronomie de Toulouse in France for a summer
research internship to learn about spider behavioral ecology. Raphael
studied the energetic costs of cobweb construction. Working with
Peter
Niewiarowski, Raphael used respirometry to measure the behavioral
costs of web spinning (spinning silk and assembling it into a web) and
calorimetry to measure the material cost of the silk itself. We are
currently analyzing the data for publication. Raphael is back in France
finishing his degree and looking forward to starting a PhD in the near
future - on spider ecology and behavior!
Jacki Zevenbergen, M.Sc. Biology,
graduated summer 2006
 Jacki
is studying how organisms can adjust their behaviors to respond
adaptively to selective pressures from both predators and prey in their
environment. Her research focuses on the cobwebs spun by black widow
spiders. These spiders dramatically alter the shapes of their webs
depending upon how much food they capture and Jacki is currently testing the
effects of these different web shapes on how black widows capture prey
and defend themselves against their own predators. Jacki received her
B.S. in Biology from U. Akron in 2005. Congratulations to Jacki for her
successful thesis defense in spring 2006!
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STUDENT RESEARCH PROJECTS
Chad Eliason "Mesh width and energetic gain in orb
spiders" - Biological Problems Summer 2006
Chad
investigated how the spacing between rows of the sticky silk (mesh
width) in orb webs affects the biomass of prey captured by spiders. By
removing every other row of sticky silk from webs, using a hot wire, we
were able to compare the prey capture of two spiders of the same species
- one with an intact web and the other with half as much sticky silk.
Preliminary analysis suggests that an increase in the mesh width of orb
webs does not affect the probability of capturing prey. However, spiders
with closely spaced spirals of silk in their webs were more likely to
capture exceptionally large prey. This suggests that the capture of
rare, large prey has played an important role in shaping the evolution
of orb web architecture. The results of this project are published in
Biology
Letters. Chad is currently studying the ecology of pileated woodpeckers at Arkansas State University.
Burhan Dahir "Development of cobwebs in the common
house spider Achaearanea tepidariorum" McNair Scholar Summer 2006
 Burhan worked in the lab through the
McNair Scholars
program at U Akron. He investigated how the cobwebs spun by the common
house spider change as spiders mature. Burhan's project included
characterizing the shapes of cobwebs and examining how the structural
and material properties of spider silk change as spiders age. He found
that both the mass of silk in webs and the sizes of individual silk
threads scale strongly with increases in body mass as spiders age. The
numbers of sticky gumfooted threads in webs, which are used to trap
prey, varied inversely with spider condition. This suggested that
well-fed spiders may reduce investment in the prey capture elements
within cobwebs even as they maintain an overall high level of investment
in silk.
Hannah Koppleberger "The
Use of Operant Conditioning and Positive Reinforcement in Training an
American Alligator (Alligator mississippiensis" Honors Thesis 2006
Hannah is an intern at the
Cleveland Metroparks Zoo and is
working on her Honors Thesis there. Hannah is testing the utility of
operant conditioning through positive reinforcement to modify the
behavior of an american alligator to facilitate its care in captivity
and to provide behavioral enrichment to the animal. Hannah received
second place for her research at the 2007 Biology Undergraduate Research
Conference and and is moving to a research internship at the National
Zoological Park in Washington, D.C.!
Jacki Zevenbergen and Steve Schulz "Condition dependent
web architecture in the western black widow Latrodectus hesperus"
Biological Problems Spring
2005
Tradeoffs between prey
capture and predator defense commonly cause changes in behavior. For
instance, starved orb-weaving spiders sometimes construct larger webs,
using thinner silk threads, than fed spiders. Within the Theridiidae,
the orb web has been transformed into seemingly chaotic cobwebs, which
depend upon tangled sheets and gumfooted threads to capture prey. We
hypothesized that cobweb spiders with more food resources would invest
more silk in webs than starved spiders and that the allocation of silk
to gumfooted threads versus the sheet would change with resource
availability. To test these hypotheses, we initially fed one group of
black widow spiders for eight days while starving a second group. We
then quantified web architectures and switched the feeding regimes
between groups for a further eight days before repeating the
quantification. We found that black widow spiders with more food
resources were heavier than starved spiders and that heavier spiders
invested more silk in webs than lighter spiders. We also found that
starved spiders invested more silk in prey capture elements, sheets and
gumfooted threads, while fed spiders directed resources into the
three-dimensional tangle. We suggest that fed spiders are allocating
silk resources toward the spinning of a defensive three-dimensional
tangle, while starved spiders allocate effort toward foraging. This
research is published in
Animal Behaviour.
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Jacki Zevenbergen |
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Steve Schulz |
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