Comparing scent glands in marals: An in-depth examination

Author info »

Introduction

Marals, also referred to as Caspian red deer (Cervus elaphus maral), are robust hoofed mammals found across a broad geographical expanse encompassing Europe, Asia, and portions of the Middle East. Among the intriguing facets of marals, their scent glands stand out as pivotal components influencing their social interactions, mating behaviors, and territorial communication. The development of these skin glands is subject to various factors, including an individual's gender, age, reproductive status, and the time of the year. Typically, sexually mature marals exhibit more advanced glandular development when compared to their juvenile counterparts. Furthermore, many mammals display heightened glandular activity during the breeding season, contrasting with their relatively subdued function during other periods. It's noteworthy that specific skin glands have been observed to regress after castration, while their growth is stimulated by the introduction of sex hormones (Staddon, B.W., 1979).

Description

Types of scent glands in marals

Preorbital glands: These glands, located near the eyes, hold significant importance in maral communication. They often manifest as small depressions or openings on the skin. The secretions from these glands may serve as territorial markers or aids in identifying an individual's physiological state.

Interdigital glands: Positioned between the hooves of marals, interdigital glands are believed to release chemical signals onto the ground as the deer walk. These signals may assist marals in navigating their environment and communicating their presence to other individuals.

Tarsal glands: Situated on the inner side of a maral's hind legs, tarsal glands produce a potent-smelling secretion. This secretion is thought to play a role in marking territory, attracting mates, and potentially deterring predators (Quay, W.B., 1986).

The scent glands in marals are a testament to their adaptability and evolutionary strategies. By emitting distinct chemical cues, marals can communicate with conspecifics without the need for direct visual or auditory contact. These signals serve several crucial purposes:

Social hierarchy and mating: Scent signals assist in establishing and maintaining social hierarchies within maral populations. Dominant individuals may mark their territories more frequently, while pheromones related to mating can attract potential mates.

Territorial marking: Scent gland secretions act as territorial markers, clearly delineating a maral's range and reducing conflicts with neighboring individuals. This conserves energy and minimizes unnecessary confrontations.

Environmental adaptation: Scent glands enable marals to efficiently adapt to their surroundings. The ability to leave scent marks on various surfaces aids in navigation, hazard avoidance, and resource location.

Comparative morphology: Comparing scent glands across different maral populations reveals intriguing variations. Factors such as habitat, diet, and social structure may contribute to these differences. The study of these morphological variations in scent glands provides insights into the coevolution of these structures with the maral's environment and behavior (Marinho, C.R., et al., 2014).

This suggests that in males, the activity of the caudal gland remains relatively stable during the transition from winter to the beginning of summer. It is hypothesized that the processes leading to the activation of its functional state, as evidenced by the enlargement of secretory cell nuclei, will peak by the end of summer, coinciding with the preparation of males for the rutting season when "odor signaling" becomes crucial. Additionally, in the semi-captive environment of red deer, where antler growth and shedding occur, the animals are housed in separate enclosures during these stages, isolated from females and young animals. These separations persist until the end of summer when they are reunited (Waterhouse, D.F., et al., 1964).

Our findings partially align with existing literature concerning seasonal variations in mammalian skin cover. While sebaceous glands typically exhibit little change between winter and summer, sweat glands often display seasonal dynamics. Considering that the preorbital gland in red deer comprises a combination of sebaceous and sweat glands and serves a marking function, the heightened activity observed during summer seems both reasonable and purposeful. Meibomian glands, being modified sebaceous glands that protect the eyes from various factors, also display increased activity during the summer due to temperature influences. Interestingly, the tail gland, despite its complexity in males during the observed periods, does not exhibit significant seasonal shifts in its functional state (Martínez‐Gómez, M., et al., 1997).

Conclusion

The scent glands of marals provide a captivating glimpse into the intricate mechanisms by which animals adapt and interact within their environments. By conducting comparative examinations, we can delve further into the evolutionary pathways that have shaped these glands, allowing them to fulfill various roles crucial to the survival and prosperity of maral populations. As we persist in unraveling the enigma of marals' scent glands, we unveil a captivating narrative that sheds light on their profound influence on the behavior and ecological dynamics of this extraordinary species.

References

Staddon, B.W. (1979). The scent glands of heteroptera. Advances in Insect Physiology, 14:351-418.

Google Scholar, Crossref, Indexed at

Quay, W.B. (1986). Scent glands. In Biology of the Integument: 2 Vertebrates. Berlin, Heidelberg: Springer Berlin Heidelberg, pp:357-373.

Google Scholar, Crossref

Marinho, C.R., Souza, C.D., Barros, T.C., Teixeira, S.D.P. (2014). Scent glands in legume flowers. Plant Biology, 16:215-226.

Google Scholar, Crossref

Waterhouse, D.F., Gilby, A.R. (1964). The adult scent glands and scent of nine bugs of the superfamily Coreoidea. Journal of Insect Physiology, 10:977-987.

Google Scholar, Crossref, Indexed at

Martínez‐Gómez, M., Lucio, R.A., Carro, M., Pacheco, P., Hudson, R. (1997). Striated muscles and scent glands associated with the vaginal tract of the rabbit. The Anatomical Record: An Official Publication of the American Association of Anatomists, 247:486-495.

Google Scholar, Crossref