Roe deer are usually very stealthy and it can be difficult to spot them at all.
They can move around very quietly and they can stand completely still blending in with their surrounding forested environment.
However, during spring (March – May), I have observed several roe deer who have been almost forcefully breaking through thickets in sites where shrubs and other undergrowth are presently budding into leaf.
In some instances, such behaviour concerns the males who are patrolling their territories.
However, in many other instances, it seems that the roe deer are purposefully rubbing against the lower branches of the shrubs.
The weather has not been very arid, and the noise has not been produced through the effects of desiccation of the woody plant organs.
Moreover, such behaviour has been observed also in females who are, during this period, even less visible than during winter, late summer and autumn.
The females have become stealthier ‘than ever’.
Yet, at the same time, occasionally, they seem to be ‘struggling’ to pass through some shrubs.
This behaviour is not accompanied by any other stress factors (such as a necessity to get away due to some threat).
In fact, I have mostly observed it when the roe deer individual has been entirely solitary, unaware of my presence and probably under impression that the circumstance was secure (safe enough to raise some ruckus).
I wonder if this behaviour is a representation of an attempt to anoint themselves with the secondary metabolites that are more abundantly produced by the new shoots and the new leaves (due to their higher nutrient value and palatability to herbivores).
Such secondary metabolites tend to have antibacterial and antifungal properties. Additionally, some of these substances could be of assistance fighting parasite infestations (e.g., fleas or ticks which have been abundant due to the early spring).
Thusly the roe deer might be conditioning their fur and skin against the aforelisted biotic stress agents.
The roe deer also moult in spring.
Part of the observed behaviour might be directed at ridding themselves of the old fur.
However, it would be more efficiently achieved by rubbing against some hard and steady surface (rather than tearing through thickets).
Old fur might attract many parasites and while it has not fallen out, the individual might be suffering higher biotic stress levels.
Meanwhile, the newly growing fur might benefit from such conditioning with natural essential oils.
Additionally, many of these volatiles are intensely aromatic and I wonder if the roe deer might be using them as ‘scent camouflage’ during periods when their hormonal production is increased due to pregnancy/territorial behaviour and when perhaps their scent could give away their location.
Roe deer do not have conspicuous scent and I believe that being ‘unsmelly’ is an important strategy for this species.
Perhaps as the intensity of their body scent rises due to hormonal activity, they prefer to apply fragrant metabolites in order to smell like their surrounding environment.
Finally, many species have adapted to use plant secondary metabolites to their own benefit (as defensive compounds or even nutrients).
While roe deer consume woody browse, perhaps application of their concentrates on their skin and the subsequent ingestion of these compounds (through the grooming activity) could serve health enhancement or even medicinal purposes (improving gut health, reducing parasite load etc.).
For example, I have heard roe deer tearing through a bird cheery grove (although most the palatable twigs would be in the edge zone of the grove) which suggests that they might have been aiming not only for application of leaf-produced substances but also for bark-based compounds.
Bird cherry leaves and bark have been used in pharmacy and cosmetics as antioxidants.
In traditional medicine, they have been used to treat respiratory ailments.
As the roe deer males, for example, are currently using their full vocal potential while, at the same time, often being exposed to damp and cold air, self-treatment with such volatiles through inhalation or slight ingestion might be of value.
I have also heard roe deer ‘struggling through’ some young pines (even through, presently, conifers are hardly their top priority forage).
Conifers, as well, have new spring growth which has anti-oxidative and anti-inflammatory properties.
(However, the pricklier thicket might be valued also as a natural ‘comb.)
Notes by Ieva 