QFASA robustness to assumption violations

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Quantitative fatty acid signature analysis (QFASA; Iverson et al. 2004) has become a common method of estimating diet composition, especially for marine mammals, but the performance of the method has received limited investigation. Bromaghin et al. (2016) used computer simulation to compare the bias of several QFASA estimators and developed recommendations regarding estimator selection. Simulations were performed using a combination of R and Fortran code. An R script was used to prepare data inputs, call EstDiet.dll to estimate diet composition given data inputs, and organize estimation results. The R script file and all Fortran functions and subroutines associated with the dll file are included in the zip file available below. The R script was developed using R 3.1.2 (http://cran.r-project.org/) and the dll file was compiled using the Intel Parallel Studio XE 2013 Fortran Compiler, professional edition (https://software.intel.com/en-us/intel-parallel-studio-xe). Bromaghin et al. (2015) used the same dll file to estimate diet composition.

Related Publications

Bromaghin, J. F., S. M. Budge, G. W. Thiemann, and K. D. Rode. 2016. Assessing the robustness of quantitative fatty acid signature analysis to assumption violations. Methods in Ecology and Evolution 7(1):51-59. doi:10.1111/2041-210X.12456

Bromaghin, J. F., K. D. Rode, S. M. Budge, and G. W. Thiemann. 2015. Distance measures and optimization spaces in quantitative fatty acid signature analysis. Ecology and Evolution 5(6):1249-1262. doi:10.1002/ece3.1429 

Iverson, S. J., C. Field, W. D. Bowen, and W. Blanchard. 2004. Quantitative fatty acid signature analysis: a new method of estimating predator diets. Ecological Monographs 74:211–235. doi:10.1890/02-4105