Do marmots display a ‘dear enemy phenomenon’ in response to anal gland secretions?

The ‘dear enemy phenomenon’ (DEP) is a form of neighbour–stranger discrimination in which resident territorial individuals respond less agonistically to intrusions by known neighbouring conspecifics than they do to strangers. We tested philopatric female yellow-bellied marmots (Marmota flaviventris) for the presence of DEP. We hypothesized that dominant females discriminated between the anal gland secretion (AGS) from female neighbours and strangers, and predicted that they would respond more agonistically (as reflected by the duration of both sniffing and physical behaviour) towards AGS from strangers than neighbours. We also hypothesized that female marmots would respond differently to kin and non-kin female neighbours, and predicted a reduced agonistic response to related individuals. Direct observations of resident marmot’s responses to the olfactory trials showed that marmots spent significantly longer durations sniffing the AGS of both neighbours and strangers than a neutral scent-free control. However, there was no significant difference in the sniffing response duration towards AGS from a neighbour or a stranger. In addition, kinship was not found to influence the responses of residents to neighbours or strangers. We conclude that, although female yellow-bellied marmots detect AGS, they do not seem to discriminate between neighbours and strangers via AGS scent marks. Other secretions may be used in territorial identification.