Case Study 96-16: The Scent Marking Behaviour of Sable Island Ponies

Investigative Science Incorporated was contacted by a Japanese research organization which was studying the wild ponies on Sable Island, off the coast of Nova Scotia. The scientist had collected faecal and urine samples from about 100 individual horses and was searching out a laboratory that could develop a way to isolate and analyze the volatile components of the samples. The analysis was to help them understand how wild stallions mark their territory.

We undertook a literature search and identified three potential methods: acid/steam distillation, essential oil extraction and dynamic headspace extraction (commonly used for forensic samples). A preliminary laboratory study of the three methods showed that acid/steam distillation and essential oil extraction were both workable. In order to monitor the recovery of the volatile material, we developed a suite of stable isotope labelled marker compounds which were spiked into each sample. These compounds were chemically closely similar to the volatiles of interest but are distinguishable by mass spectrometry. This innovation markedly increased the reliability of the analysis. 

Using these approaches, over 100 samples were analyzed at our laboratory. The results were published in a peer-reviewed scientific journal (R. Kimura, Volatile substances in feces, urine and urine-marked feces of  feral horses. Can. J. Animal Science, 81:411-420, 2001).