Coypu are invasive rodents that are ravaging wetlands across their introduced range. Coypu have a sexually dimorphic (male larger) anal gland (AG) used in scent marking behavior. Using GC-MS, this study looked for a similar dimorphism in compounds produced by the AG. Male AG extract contained 15 compounds. Of the 15 compounds, 6 are fatty acids of known structure. Nine of the compounds are partially characterized farnesene isomers. Each male AG chromatograph had the same compounds present, but in differing proportions. This suggests that coypu can use AG secretion to identify individual males. Such knowledge of compounds used in coypu chemical communication could be useful in developing coypu-specific attractants. The second part of this study used a computer program to identify individual coypu by marking and matching whisker-insertion patterns. It was found that whisker insertion pattern can be used as a ?fingerprint? to aid in the photographic identification of individual coypu.