Effectiveness of femur bone indexes to segregate wild from captive minks, Mustela vison, and forensic implications for small mammals.

Utilization of free-living populations of endangered wildlife species is usually strictly prohibited or restricted. Farming of endangered species can provide products that are in demand as a countermeasure. A novel forensic issue arises because it becomes necessary to discriminate the origin of given wildlife products. We tested the effectiveness of five measurements and four indexes of femur bone using farmed minks (n=40) and escapees (n=32). Results showed all measurements, namely body mass (L-f), body length (M-f), femur mass (V-f), femur length (M-b), and femur volume (L-b), were highly discriminatory. However, they are susceptible to the influence of nutrition level and sex. Femur length index (I-fl), femur linear density (D-l), and femur volume density (D-v) eliminated the influence of level of nutrition and were highly effective. However, I-fl and D-l were influenced by sex (p=0.000). Because D-v was not influenced by sex (p=0.683) and was highly effective, it was the preferred index.