I was wondering if any mate preference experiments have been done on rodents (especially nocturnal rodents) in the field. I know Chandler and Zamudio recently used a seminatural enclosure with spotted salamanders and paternal genotyping to asses mate choice, and other studies using enclosures and recently derived wild/lab stocks of mice to look at MHC mediated mate choice. There are also many genetic studies that assign parentage based on the pool of sampled males. I just wanted to know if anyone knew of other ways to try and asses mate preference when you cannot create an enclosure and when you can only sample a fraction of the population.
Thanks for your help, Jamie -- Jamie Winternitz Graduate student Odum School of Ecology University of Georgia, Athens -------------- Original message -------------- From: Carl Fitz <cf...@ufl.edu> > Regarding Dick Wiegert's work on modeling, and understanding ecosystems > - much of his work & publications dealt w/ this general topic of > integrating field measurements w/ ecological models - aquiring data > suitable for parameterizing (& validating etc) relatively simple models > of trophic interactions. He worked in thermal springs, salt marshes, > and a variety of other systems. (I was a student of his; he died a > number of years ago). > > Another of his papers that gets into the topic of the tradeoffs between > model generality, realism, and precision: > Wieger, R.G. 1979. Population models: experimental tools for analysis > of ecosystems. In: Horn, D.J, G.R. Stairs, and R.D. Mitchell. > Analysis of Ecological Systems. Ohio State University Press, Columbus. > pp. 233 -275. > > Another paper of interest on this topic: > Costanza, R., and T. Maxwell. 1994. Resolution and predictability: an > approach to the scaling problem. Landscape Ecology 9:47-57. > > -carl fitz > > > Bill Silvert wrote: > > After I mentioned a paper by "Weigert" in a posting I have received > > numerous > requests for the reference. The correct spelling is Wiegert. My apologies to > all > of you, especially Prof. Wiegert. > > > > I am currently travelling and do not have the reference with me, but I > > found > his website and the paper may be > > > > Wiegert, R.G. 1975. Simulation models of ecosystems. Ann. Rev. Ecol. Syst. > 6:311-338. > > > > although I thought it was earlier. The paper describes about half a dozen > models of a simple salt spring ecosystem, and as I wrote earlier, he found > that > the best performance came with an intermediate level of complexity. > > > > I've been asked in another posting why complex models do not work too well. > There are many reasons for this, including the need for too many parameters > and > resultant magnification of errors, but in ecological modelling when you get > too > specific and try to model individual species you need to describe the factors > behind zonation and succession, which is hard to do. In general I find that > fairly aggregated models work well, especially when aggregated on the basis > of > function rather than taxonomy. > > > > Another problem is that very precise models are more susceptible to > > problems > arising from discontinuous processes, such as insect outbreaks and blooms > (algal, jellyfish, etc.). Unless we know precisely what triggers these events > and know how to predict the events, the models will not perform well. > > > > I recall a modelling exercise where the components of an estuarine > > ecosystem > were modelled by separate groups of scientists. All went well, except that > the > head of the zooplankton group insisted that all four of the Acartia species > he > was studying be modelled individually. They never managed to do this (again, > problems of zonation and succession) and the project would have been aborted > if > the rest of us hadn't thrown together a simpler but working submodel. > > > > Not everything can be successfully predicted. This is a property of natural > systems, not just ecological models. I have already mentioned the cod-haddock > issue on this list. Modelling fish recruitment is tricky because it depends > on > the overlap between larval emergence and plankton blooms, which we generally > cannot predict. We cannot do very well at predicting earthquakes either. And > in > mathematics, remember Gödel's famous proof that not all true theorems can be > proven. Failure to do the impossible is not really failure (unless you are a > Marine!). > > > > Ciência Silvert > > www.ciencia.silvert.org > > > > > > > > -- > H. Carl Fitz, Assistant Professor, Landscape Ecology > Soil and Water Science Dept. > Ft. Lauderdale Research & Ed Center > IFAS, University of Florida > 954-577-6363 > cf...@ufl.edu > http://ecolandmod.ifas.ufl.edu
