Genetic models for the inheritance of the silver colour mutation of foxes

We consider genetic models for the inheritance of the particular colour patterns of silver foxes. The models are evaluated by computation of statistical likelihoods based on observations of related foxes in extended pedigrees. Problems caused by incomplete paternity information are addressed by inferences based on phenotypic observations. The unreliability of subjective evaluations of fur colour also provides difficulty, in particular crossfoxes emerge as being difficult to differentiate. No evidence of linkage between Agouti locus and Extension locus is found in this dataset.