Information of the age of rivals does not impact the scent marking behaviors in male meadow voles

Many terrestrial animals use scent marking behaviors as a major form of communication. The scent marking process involves the systemic depositing of odors from metabolic byproducts, urine, or feces, from specialized glands, or from the orbital gland into the environment. The odors deposited by the animals convey a range of information such as sex, age, reproductive condition, individuality. Scent marking makes information available without needing the signaler present.

Because individuals of the same species can place their own scent mark on top of another’s, individuals must be aware of their social situation based of current or past social information. This information determines where an individual places their mark, when to place it, which scent marks they respond to, and how they do so.

The scent marking behaviors of the meadow vole are affected by social information via odor. During breeding season, the females claim a territory and the males wander them. They then rely on odors to secure a mate. Because males wander different territories, they should demonstrate flexibility with their scent marking behaviors based on social information available. They already shown adjustment of self-grooming to a social odor based on information of a rival male’s age. Males self-groomed more to a social odor that had a female ordered with a younger rival compared to when it was with an older rival. This had scientists wondering: do male voles show similar adjustment with scent marking behaviors? Scientists hypothesized that males will reduce their scent marking depending on the relative age of their rival.

During the control test of their study, scientists found male meadow voles placed more urine scent marks where a female odor was detected compared to the clean, unused bedding. Additionally, they found males’ urine scent marked similarly where social information of a younger rival with a female odor and where social information of a older rival with a female order was found. Males did not show a preference for the female odor with association of a younger rival or the female odor with association with an older rival. Of the 41 males, 16 showed preference for the female odor associated with a younger rival, 14 showed preference for the female odor associated with an older rival, and 11 did not show preference for either female.

With these results, the scientists’ original hypothesis was not supported. Male meadow voles did not adjust their urine scent marking like they did with self-grooming based on social information. It was then hypothesized that self-grooming and scent marking may serve two different functions of chemical communication. Their difference in function may be the result of difference in chemical composition of each secretion.

Social information not only can provide an individual with information about the signaler,  but also how other individuals are interacting or showing reproductive interest. The results of this study demonstrates flexibility of how social information is used in communication. This flexibility will give males an advantage when searching for mates and therefor increasing their fitness.

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