Individual signatures in scent gland secretions of Eurasian deer

Evidence for individuality of odour profile, coding for individual identity , was sought in scent profiles derived from natural secretions of the preor bital gland of red deer Cervus elaphus (n = 26), sika deer C. nippon (15), fallow deer Dama dama (50), Chinese muntjac Muntiacus reevesi (23) and Chin ese water deer Hydropotes inermis (53); from metatarsal secretions from red deer (n = 35), sika (30), fallow (193) and roe deer Capreolus capreolus (2 6), and from roe deer interdigital glands (II = 48). Volatiles were eluted from sample materials at body temperature, to restrict analysis to those el ements that would occur within the natural odour signal; the different vola tile elements were then separated by gas chromatography. For each species c onsidered, secretions from at least one scent gland were individually disti nct and sufficiently complex to code for identity. Within our samples no tw o individuals produced identical odour profiles; yet in analysis of metatar sal gland secretions of individual fellow deer sampled in successive years, odour signatures of individuals remained consistent over time. The wider p otential for individual coding was assessed through calculation of the numb er of different possible combinations of all volatiles recovered in any spe cies x gland system. Every secretion considered seems to have the potential to provide individually characteristic signals (with the exception of secr etions from the fallow deer preorbital gland, which notably contained no od our information under any analytical system). Complexity of signals differe d markedly between species as did the gland-type responsible for production of the most complex or distinctive signal. No simple evolutionary patterns are apparent to account for this variation and we suggest that the form of gland selected for production of a signal carrying information about indiv idual identity is a function of habitat type and sociality.