On the Relationship between Scent-Marking and Territoriality in Callitrichid Primates

Across a diverse range of animal groups, scent-marking is integrally related to the defense of territories and maintenance of social status. However, using data from a field study of wild saddleback tamarins (Saguinus fuscicollis), the authors of a recent paper claimed to find no evidence to support a relationship between scent-marking and territorial defense. Here I review the same evidence and argue that the data are consistent with the idea that scent-marking plays a critical role in territorial defense. This argument includes an attempt to clarify some misconceptions about the scent-marking mechanism that exist in the literature. I then reexamine the evidence in light of a proposed alternative function for scent-marking (that scent marks are used to explore reproductive opportunity and achieve extragroup copulations), and highlight some critical tests that could serve to distinguish between the two functional interpretations. Scent-marking could serve both in territorial signaling and in signaling to mates, but current evidence suggests that territorial defense is more, or at least equally, likely to be the primary function of scent-marking in callitrichids.