Software for the calculations outlined in the 2002 paper are available on Bolnick's webpage: https://webspace.utexas.edu/dib73/Bolnicklab/Programs.htm?uniq=-u6mdgi
Ned ***************************************************** Ned Dochtermann [EMAIL PROTECTED] http://www.unr.nevada.edu/~dochterm/ 775-784-6781 Graduate Group in Ecology, Evolution and Conservation Biology Fleischman Agriculture Building, Room 145 University of Nevada, Reno ***************************************************** Quoting Mario Quevedo <[EMAIL PROTECTED]>: > Hi Tony, > > Just in case you have not check this one out for a lead: > > Bolnick, D.I., Yang, L.H., Fordyce, J.A., Davis, J.M., & Svanbäck, R. (2002) > Measuring individual-level resource specialization. Ecology, 83, 2936-2941. > > Then if you have way more than the frequencies, I'd say you could combine / > reduce the info and make yourself your own "impact on prey" index, and use > it as a continuous variable as described in the cited paper. > > Mario Quevedo > Unidad de Ecología, Dept. B.O.S., > Universidad de Oviedo > Campus del Cristo, 33071 Oviedo > Spain > > phone: +34 98 510 48 31 > fax: +34 98 510 48 66 > [EMAIL PROTECTED] > > > >hi all, > > > >im currently grappling with the task of getting some measure of the trophic > >niche width and niche overlap of an assemblage of consumers and am finding > >it difficult to follow the literature. i have a list of consumers and > >corresponding consumption frequencies for a series of prey and am chasing a > >suitable measure that will highlight the approximate width of the niche of > >each consumer along this resource dimension (ie food type), and a separate > >measure that will enable me to estimate pair-wise overlap between them (i do > >recognize such an approach has limitations - eg that overlap does not > >necessarily indicate competition). much recent work seems to simply use > >number of prey taxa as an index of niche width, but im keen to try and go > >further than this. specifically, i have data on consumption rates of each > >consumer on each prey type and prey availability, which i know some previous > >work included into both a breadth and overlap index. > > > >it seems that much work was done in the 70's/80s (eg hurlbert, pianka, > >levins, macarthur, slobchikoff & schultz, pielou, colwell & fatuyma, abrams) > >on this topic and the result was a mass of different equations - each of > >which is apparently more suitable than the next! i was wondering if there > >was any solid conclusions from this work (ie is there a best-measure) and if > >there is any recent work that summarizes/extends these ideas? > > > >any help/leads would be much appreciated, > > > >cheers, > > > >tony > > > >__________________________________________ > > > >tony dell > >department of zoology and tropical ecology james cook university townsville, > >qld 4811 australia > > > >ph 07 47814757 or 47814520 > >fax 07 47251570 > >email [EMAIL PROTECTED] > >========================================================================= >
