In this post, I would like to propose that roe deer male spring territoriality is characterized by three stages:
- Resuming territoriality (frequent patrolling vocalizations);
- Confirming territorial configuration (less frequent patrolling vocalizations characterized by neighbour-neighbour interactions);
- Established territories (rare and brief vocalizations).
I could classify these stages according to month in which they occurred in 2024 (1 – March; 2 – April; 3 – May).
I do not suppose, however, that the month itself is relevant and I believe that the resumption of territorial behaviour is determined by renewed growth of woody/forest vegetation rather than by temperature or photoperiod (see Roe deer observations (the week around Mar 20, 2024) – resuming territoriality).
Thereby, these stages would be subject to annual fluctuations and, in some years, phase 1 might be observed later (e.g., in April).
I believe that all of these stages (and male territorial behaviour itself) are dependent on female (reproductive) metabolism and the transitions among the stages occur according to the female’s body condition and fetus development.
It is worth noting that, in my view, roe deer males are not territorial in spring due to their own self-interest (more precisely, due to their interest in future mating prospects) but due to the interest invested in the currently pregnant female.
I believe that stage 1 is aimed at ensuring that the female’s range will not be imposed upon by a too great number of males (neighbours and dispersing males).
During stage 1 and stage 2, males sometimes accompanied females and demonstrated guarding behaviour (Roe deer observation (Apr 12, 2024) – my theory of males protecting pregnant females).
They were more active and conspicuous than females but, according to my observations, while they patrolled predominantly the areas which were being used by females and which would serve as birthing grounds for females, they did not forage in these areas.
These areas were the riparian forest areas which, at the time, provided the ‘freshest’ growth of woody plant growth and woody plant associates.
It was only during stage 3, the males began recovering after the winter and after the intense territorial behaviour and I also started observing them foraging in the forests more frequently (rather than somewhere out in the open, as before).
This was, coincidentally, a time when woody plants were already extremely abundant (approximating early summer conditions) but it was after the more accessible and perhaps palatable plants (ground cover, shrubs, understorey) were already in full leaf.
Thus, I conclude that the males refrain from utilizing the new woody growth leaving the earliest species and most accessible/palatable species for the pregnant females.
During this time, they were chasing other males out of female ranges (especially, out of habitats where females foraged most often which were also rather sheltered that must have been important during the period when weather was yet unsteady with very warm and very cold spells).
Their territorial behaviour, in my regard, also served to draw any attention to the males themselves and away from the females who were being very quiet, concealed and unnoticeable.
Once the females had gained sufficient body condition and neared parturition, the males had already established the territories and they grew quieter – possibly, not give away female/fawn locations to predators because the fawns would have reduced mobility and they would center around their birth site.
Namely, while the female was pregnant, the male could draw attention to himself by being loud and conspicuous.
When she was close to giving birth (reduced mobility by the female herself) or when she had already given birth, the conspicuous behaviour would not be as helpful because it would make most sense not to draw attention to the area at all (because the female/fawn would not be able to use the male’s noisy display as a cover behind which to escape).
I believe that the entire territorial timing was based on the female’s pregnancy.
The aforementioned stages were as follows:
1
The males patrolled the territories regularly barking very loudly and for prolonged period of time (even 15 minutes or more).
Such behaviour ensured that other males (neighbours and dispersing males) learned the territorial configuration.
I believe that much of the behaviour was aimed at neighbours and it was not altogether aggressive (also, some chasing out of trespassers was observed).
As the roe deer do not scent mark clearly delineated territorial boundaries, they probably need to ensure that any areas where two male ranges come closely together, are defined in their ownership and this is achieved through vocalizations that, just like in songbird species, serve as an ephemeral ‘map’.
Roe deer rely on stealth and inconspicuous behaviour with regard to anti-predator strategies and therefore leaving permanent territorial marks might not be preferable in this species.
Thereby, the neighbours must memorize the territorial distribution from the vocalizations given by the males.
This would probably also be a time when territorial disputes occur where two males whose ranges are close by, must agree on their perceived (but not truly set in any lasting manner) boundaries.
This would also be a time when perhaps new males contest the older males.
However, I believe that the main purpose of the entire ‘show’ is not to abandon social life but to redefine it into a new social order.
I suppose that the vocalizations are aimed at achieving a peaceful understanding among the neighbouring males (who are familiar with one another and who might have socialized more closely during winter) regarding their spring/summer ranges and their spring/summer ranges are probably mainly determined by the needs of the female.
I think that the males do not predominantly defend their territory but they ensure that the female’s range (which overlaps their range) and the most crucial habitat patches on her range, will not be depleted.
Thusly, the males might not be truly competing for access to females during the subsequent mating season but they might be determining who is the best-fit protector of the female’s resources during her current pregnancy.
This is a period when the female begins to forage in the forested habitats and she is as ‘conspicously inconspicuous’ as the male is the centerpiece of attention (also by predators).
The female can forage on the new growth of perhaps some of the most palatable forest plants during hours when the habitat provides shelter against the elements while the male is trotting around, not foraging at all and exerting much energy.
2
As the understanding between the neighbours has been reached (through the mechanisms or memory which are, essentially, social), the males do not invest as much in the vocalization behaviour any longer although it is not abandoned.
Lone males must be present at all times and this reduction in vocalization activity/intensity suggests to me that the main purpose of vocalizations is to come by agreement with the neighbours regarding the spring/summer arrangements.
Vocalizations are still performed but they are shorter and less frequent.
This stage is also characterized by what I consider ‘testing of boundaries’.
As the ranges are not marked permanently (and the configuration has to be memorized), I believe that, during this stage, neighbouring males sometimes approach one another’s range perhaps in vulnerable/unclear/disputed or simply highly desirable areas (or areas that they believe might be necessary for their female) and they try to figure out whether the neighbour will be permissive or whether barking will ensue.
I think that these intrusions are not active territorial contests but they could rather be described as ‘nuanced negotiations’ (much like talking over the finer details of a general agreement).
These ‘almost trespasses’ do not result in conflict and, verily, they are more often ‘almost’ than they are actual trespasses (the neighbour simply approaches the other neighbour’s range without intruding and elicits (or does not elicit) a territorial response).
I am not certain whether, historically, conversations have been held among neighbours during this stage but they occurred this year which was perhaps an extraordinary year because the wintertime social arrangement might have been abandoned before the males were prepared, hormonally and psychologically (see Roe deer observation (Apr 26, 2024) – five neighbour assembly and Roe deer observation (Apr 29 and May 1, 2024) – conversation between two neighbours).
The males can rest more and they can forage more often but I have mainly seen them foraging in habitats that are more open than those frequented by the females.
Coincidentally, the vegetation has leafed out and the females are far better hidden in the forested habitats (they might not need the male’s assistance in drawing attention away from them because they are concealed in their spring/summer patches).
I also think that it is difficult for the females to resume a more solitary lifestyle and perhaps some of the vocalizations by the males are purposed to ensure company for the females who can gradually adjust from winter to summer social life and habitat use.
3
The females have been able to consume most of the ‘freshest’ and accessible forest plant growth.
The males have made their neighbouring arrangements and they have confirmed them in detail.
The males now bark relatively rarely (possibly, upon being startled or when still unsure about another male’s – neighbour’s or dispersing male’s – intention).
They forage on the woody plants in the forested areas although those are presently not as fresh anymore (the freshest growth is that of the tree species which are more difficult to access because the branches are often higher).
I suppose that only now the males begin recovering after the winter and after the intense territorial behaviour.
This springtime territorial behaviour must have been costly to them and, throughout summer, the males (and females without fawns) will forage more frequently in semi-open or open habitats than females with fawns.
My overall conclusion is that all of this effort is invested not in the autumn mating opportunity (at least not predominantly so) but in the current pregnancy by the female, in her dietary/metabolic needs, in her habitat needs (for spring and for summer) as well as her need to be protected (against predators but also against depletion of her resources by conspecifics) and to be supported during the shift in social life and habitat use.
The vocalizations are aimed mostly at neighbours which suggests that social behaviour ensures but it is rearranged to respect the needs by the females.
Territorial disputes, during this time, might not even be about access to females but about the female’s (represented by the respective male) access to crucial habitats.
Notes by Ieva 