Spotlight on our Postgraduates – Amanda Niehaus
research that I did last year in the US and Brasil was lots of fun,
and I learned a lot about working with other scientific styles in
the process. In those 6 weeks, I was involved in the design and running
of several different projects and worked on developing dynamic programming
techniques and optimality theory to study thermal acclimation. Though
it was an intense trip, I enjoyed a lot of Mexican and Brasilian food
and American microbrews, and got to see how far my Spanish got me
in a Portuguese-speaking country.
In the short-term, I’ll be finishing my PhD this August and
having a baby in September. Next year (when I’m hopefully sleeping
again), I plan to continue along an academic career track by expanding
my collaborations with overseas researchers and working towards obtaining
a postdoctoral fellowship to continue research. Following on from
my PhD, I’d like to examine how environmental variability affects
the ecology and evolution of ectotherms, ideally in a model system
with important conservation or health value.
Enticing crickets to run in a CT room in Indiana
at temperatures between 8-44C.
Though environmental conditions change around us all the time, relatively
few laboratory studies have considered the consequences of diel
temperature variation on organisms. Instead, most compare phenotypes
among un-natural stable conditions, which limits how much we can
say about organisms in the real world. In my PhD thesis, I use both
theoretical and empirical approaches to understand how rapid temperature
changes affect patterns of development and acclimation in ectotherms.
In my research, I’ve raised striped marsh frogs (Limnodynastes
peronii) and fall field crickets (Gryllus pennsylvanicus)
in a range of conditions to determine whether:
morphology, physiology and locomotor performance of organisms
differs between stable and fluctuating temperatures as predicted
by current acclimation theories
variability has carry-over effects between life-history stages
we can use data collected at stable environments to predict outcomes
in fluctuating ones
organisms respond differently to unpredictable versus predictable
answering these questions, I’ve measured a number of important
life-history and physiological factors such as developmental rates,
growth rates, swimming or jumping performance, metabolic rates,
heart rates, and feeding patterns. Basically, I’ve shown that
it’s difficult to predict phenotypes of organisms in fluctuating
environments and that existing optimality and life-history theories
do not adequately explain responses to short-term variability. I
hope that my work will have important implications for experimental
biologists, as it shows how incredibly important it is to use realistic
thermal regimes in laboratory studies.
You can actually see the tadpoles' hearts through their bellies, making
measurement of heart rate fairly simple.
Once I got very lucky and found some eggs in
a scenic location while on a cycling trip.
Ephemeral pools where temperatures often vary dramatically every day.
My typical lab setup.
PhD research would not have been possible without the support
of my PhD supervisors Craig Franklin and Anne Goldizen, my partner
Robbie Wilson, and collaborators in the US (Mike Angilletta)
and Sydney (Frank Seebacher).
Niehaus, A.C., M.J. Angilletta, C.E. Franklin and R.S. Wilson. In
review. Predicting anuran phenotypes in complex thermal environments.
Angilletta, M.J Jr., T.C. Roth II, R.S. Wilson, A.C. Niehaus, and P.L.
Ribeiro. In review. The fast and the fractalous: Speed and tortuoisity
tradeoff in running ants. Functional Ecology.
Angilletta, M.J Jr., R.S. Wilson, A.C. Niehaus, M. Sears, C.A. Navas and
P.L. Ribeiro. 2007. Urban physiology: City ants possess greater thermal
tolerance. PLoS One 2(2): e258.
Niehaus, A.C. and R.C. Ydenberg. 2006. Ecological factors associated with
the migratory phenology of high-latitude breeding Western Sandpipers.
Polar Biology 30:11-17.
Niehaus, A.C., R.S. Wilson and C.E. Franklin. 2006. Short- and long-term
consequences of thermal variation in the larval environment of anurans.
Journal of Animal Ecology 75(3): 686-692.
Ydenberg, R.C., A.C. Niehaus, and D.B. Lank. 2005. Interannual differences
in the relative timing of southward migration of male and female western
sandpipers (Calidris mauri). Naturwissenshaften 92:
A.C., D.R. Ruthrauff, and B.J. McCaffery. 2004. Predator attraction to
Western Sandpiper nest exclosures. Waterbirds 27 (1): 79-82.
Niehaus, A.C., S.B. Heard, S.D. Hendrix, and S.L. Hillis. 2003. Measuring
edge effects on nest predation in forest fragments: Do finch and quail
eggs tell different stories? American Midland Naturalist 149: