title: Erroneous behaviour of MixSIR, a recently published Bayesian isotope mixing model: a discussion of Moore & Semmens (2008).
abstract: The application of Bayesian methods to stable isotopic mixing problems, including inference of diet has the potential to revolutionise ecological research. Using simulated data we show that a recently published model MixSIR fails to correctly identify the true underlying dietary proportions more than 50% of the time and fails with increasing frequency as additional unquantified error is added. While the source of the fundamental failure remains elusive, mitigating solutions are suggested for dealing with additional unquantified variation. Moreover, MixSIR uses a formulation for a prior distribution that results in an opaque and unintuitive covariance structure.
authors.affiliation: Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland. a.jackson@tcd.ie
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Jackson
authors.forename: Richard
authors.initials: R
authors.lastname: Inger
authors.forename: Stuart
authors.initials: S
authors.lastname: Bearhop
authors.forename: Andrew
authors.initials: A
authors.lastname: Parnell
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D003198:Computer Simulation; D004032:Diet; D020387:Food Chain; D005518:Food Preferences; D007554:Isotopes / Q000378:metabolism*; D008954:Models, Biological; D015233:Models, Statistical; D012680:Sensitivity and Specificity; D012984:Software
chemical_list: D007554:Isotopes