Analysis of badger urine volatiles using gas chromatography-mass spectrometry and pattern recognition techniques

The potential for badger urine to signal olfactory information relating to sex, age class and seasonality was investigated by performing GCMS headspace analysis followed by pattern recognition statistical analysis on 84 urine samples collected from different categories of animal. Approximately 300 compounds were identified using library searching, and GCMS peak areas were recorded for the 33 most common. PCA was performed on the normalised and standardised data from all badgers, through which significant seasonal trends and groupings of homologous series of compounds were detected. PCA was also performed on the three subgroups of adults in the spring, summer and autumn, and a level of sexual discrimination was possible during the latter two seasons. Malanobis distances on the scores of the first five principal components provided good discrimination for these three subgroups, but discrimination was poor when all samples were analysed together. This, combined with the initial results of the PCA, confirms that a strong seasonal trend is imposed upon the sexual trend in this dataset. Our initial analysis indicates that badger urine potentially contains olfactory cues relating to sex and season. The relevance of these findings to understanding olfactory communication in mammals is discussed.