Histological analysis of scent glands in banded mongooses, with implications for chemical communication

Abstract Chemical communication is the most ancient and widespread form of communication. In many species, specialised structures called scent glands have evolved to facilitate this communication. These glands vary considerably among species in structure, size, body location and the composition of their secretions. Histological analysis is therefore required to confirm the presence of scent glands, identify secretion types and assess potential roles of the immune system and microbiota in modifying secretions. Here, we investigated the distribution and structure of scent glands in the banded mongoose ( Mungos mungo ), a cooperatively breeding, group‐living mammal. We found that individuals possess two large (1.5 cm diameter) anal glands, each consisting of a central sac surrounded by glandular tissue. This in turn is surrounded by a layer of striated muscle, which likely facilitates the deposition of relatively large quantities of odorous chemicals when engaging in deliberate scent marking behaviour. The glands are lined by two different types of epithelia (keratinised and non‐keratinised) which may impact how immune genes such as the major histocompatibility complex (MHC) affect the microbiome of the glands, and therefore, the chemicals that are secreted during scent marking. Additionally, we reveal a previously unidentified small (0.75 mm in length) scent gland in the cheek, which may be used for scent marking. We provide evidence that banded mongooses may use their chin and abdomen for scent rubbing, as these regions are often rubbed in odorous substances, but we found no evidence of specialised scent glands in these areas. Our findings highlight the importance of integrating anatomical, behavioural and biochemical approaches to understand the mechanisms and purposes of scent communication. This study serves as a foundation for future research on the interplay between scent marking and rubbing behaviours, and the role of immune genes and microbiota in shaping chemical communication in banded mongooses and other mammalian species.