IndSpec1: a program to calculate measures of individual specialization.
Ecological Archives E083-056-S1.
Authors
File list (for downloading)
Description
Daniel I. Bolnick
Center for Population Biology
Storer Hall, One Shields Ave.
University of California, Davis
Davis, CA 95616 USA
dibolnick@ucdavis.edu
1. IndSpec1 - The executable program (.exe file, downloaded in .zip format).
2. IndSpecReadMe - The .pdf file with instructions on how to use the program (downloaded in .zip format).
3. SourceCode - The C++ source code for the program (downloaded in .zip format).Download all files at once: IndSpec.zip
Our print article describes several indices that quantify the degree of inter-individual variation in resource use within a population, also known as individual specialization. This supplement allows users to download IndSpec1.exe, a program that calculates all the indices discussed in the paper by Bolnick et al. This program is executable on Windows platforms. IndSpec1 reads tab-delimited data files in which each row of the data matrix represents the diet data for a single individual in a sample. This row-vector for an individual can either be a list of prey sizes or other continuous measurements of a collection of prey used by that individual. If resource use is described by categories rather than a continuous measure, the individual's vector can represent the numbers or masses of prey used by an individual that fall into each resource category (each column). IndSpec1 then provides the user with the option to calculate any of the indices of individual specialization: WIC, BIC, and TNW (for continuous data); WICs, BICs, and TNWs (the Shannon-Weaver-based equivalent for discrete data), the proportional similarity between each individual and the population diet (PSi); the average proportional similarity (IS); the pair-wise proportional similarity between individuals; and Petraitis' likelihood measure of specialization for each individual (Wi), and the mean Wi. In addition to calculating each of these indices, the program can generate a null distribution for several of these indices, corresponding to the hypothesis that all individuals sample randomly from a single (population) diet distribution. This null is generated by a Monte Carlo bootstrap in which the program repeatedly assignes each individual new diet items drawn randomly from the population's resource distribution. The program provides the option to save most results to text files.
The program is accompanied by an instruction file (ReadMe.pdf), that describes in detail both how to format data files to be read by IndSpec1, what calculations the program performs, and how to use the program. A third file provides the original C++ source code for the program. All files can be downloaded singly by clicking on each file's icon (above), or together. After unzipping the files, IndSpec1 can be executed by clicking on its icon. The .exe file should be placed in its own folder, and all data files should placed in this folder prior to analysis.
Users are welcome to contact the program's author (dibolnick@ucdavis.edu) with questions, problems with the program, ideas for additional features to incorporate, and programming suggestions.
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