I have renamed this post from ‘An observation of what might be strange roe deer female behaviour (grouping in summer)’ to ‘Roe deer grouping in summer’ because the abundance of their grouping behaviour observations (and the inclusion of males and possibly even fawns) has evidenced that this is not strange behaviour, at least not in my region.
Recently I have noticed an interesting situation regarding roe deer in my area.
The roe deer in Latvia usually mate in August, become territorial in April and give birth in May/June.
The ‘study site’ is a small town and its semiurban surroundings that consist of riparian forests, riparian meadows, small private vegetable gardens and orchards and some agricultural fields.
Now it is June already and for several mornings I have observed two female roe deer feeding together in different areas (within about 1 km2 of range).
Sometimes they have been grouping also with the territorial male.
Sometimes I have observed only one of them feeding together with the male.
They have been feeding in different spots and sometimes they appear to be travelling together.
At least, when they are fleeing (from me as the disturbance), they are taking the same direction.
One morning I met the two females who were feeding in the long grass below apple trees in an orchard.
Due to the long grass, I mostly saw the ears of them and I even assumed those were red deer because I knew that roe deer females should be holding rather exclusive ranges in summer and that herding behaviour in roe deer should be resumed in autumn.
However, the height of the animals as well as later observations of what I believe to be the same individuals (on which occasions the visibility was improved and I could better appreciate the body size, the shape and the manner of moving which are very different between roe deer and red deer) suggest that they were not reed deer females.
These same two females I have also met on another feeding spot about 500 – 800 m away from the aforementioned orchard.
This means that they are not merely ‘meeting up’ at the orchard because it is a more expansive and favoured foraging ground that might lie on the border between their ranges (roe deer female territory sizes might be as small as < 0,5 ha or 1 km2).
During early morning hours there is not a severe lack of foraging areas available, either, that would force them to feed on the same spot.
I think they could easily avoid one another if choice in foraging grounds was the determinant factor.
As stated before, when the two females noticed me, they fled and they took the same direction which is suggestive of some degree of cooperation and cohesiveness.
I have seen these two females on another feeding spot on another occasion – about 500 m from the orchard (when they did not flee because roe deer do not take flight that often in our area at mere sight of a human unless they are startled).
I have seen them separately (although I cannot tell which one I met because I cannot differentiate between the two females, unfortunately).
I have seen them also with the territorial male on which occasion they were walking along the dirt road passing along the garden patches and then they ran together downhill toward the riparian meadow where I later saw the three of them feeding.
Before fleeing, they appeared to be ‘counseling’ one another on what action to take (to flee or not to flee) and what direction to take which is a typical grouping behaviour.
From what I have read, I thought that female roe deer also hold rather exclusive territories during summer (fawn-birthing and fawn-rearing season) which can overlap but that the females do not group during this period (although females might group with males whose territories tend to overlap entirely those of one or two females).
While these females might be related (two sisters or a mother and a daughter) due to low dispersal distances and philopatry in the roe deer species, I find it curious that I have seen them feeding and travelling together in different spots across the local landscape during June.
The population density does not appear to be exceedingly high.
I have read that roe deer males hold smaller territories that overlap with only one female if the population density is high.
In this case, the male roe deer was apparently overlapping with two females.
Also, female roe deer without fawns (if that were the case and the reason for at least one of them seeking group contact), tend to have smaller home ranges (Tufto, J. et al., 1996) but these two females apparently ranged over rather the same area.
The area was also rather large (for roe deer) which might suggest that the females were reproductively active (raising offspring).
I cannot, unfortunately, determine the reproductive status of these females.
They both appear of the same size.
However, if sexual maturity is reached at about 1 year of age and one of them (or both of them) were born only last year, they have not bred yet and therefore they are not raising fawns.
It is also possible that one or both of them have lost their fawns (this has been a very cold spring and some predation by foxes is also an issue).
Currently, the fawns are not yet following their mothers around (but most fawns should be born already) and if the fawns are hiding and not with their mothers, I cannot really determine from what I observe if the females are lactating.
I am very curious to understand this behaviour.
Could it happen that, for example, immature roe deer sisters stayed together until their first rut (later in the summer) or that an immature daughter stays together with her mother or is tolerated by her mother on their overlapping range until the daughter’s first rut?
And if those are two mature adult females, would such behaviour of feeding together in summer occur often if they both had fawns?
I think this is an interesting case study and I will be following the situation as it unfolds.
***
Since I made my observations, I have also encountered different claims on female roe deer territoriality among researchers.
While roe deer males are strongly territorial during summer, it appears that the female roe deer behaviour is less clear.
Some authors state that female roe deer are not territorial and some claim that they are protective of their core (fawn-rearing) areas but not of their entire home range.
Still, it would appear overall that their ranges are not as exclusive as those of male’s, however, they would not be as tolerant toward other females as outside of the reproductive season.
Avoidance and aggression might be used and grouping is probably not very common.
***
I have gathered a few more observations.
In July the roe deer males appear to be feeding and travelling alongside females that are slightly smaller than adults and that are perhaps does born last spring (potentially, daughters but perhaps unrelated to the buck).
These smaller females are far more anxious than adult females and upon seeing me and my dog, they bolt almost at once.
But far less frequently so when with a male.
It appears that they draw confidence from the presence of the male although this might be explained not by active defense on behalf of the male against predators (us) but rather by observing the male’s peaceful reactions to us (the males seem the least perturbed during these chance encounters).
I also often see the smaller (subadult?) females seeking the company of male or older female.
On two occasions this summer, these females (which when encountered in solitary situations, always flee without much hesitation) alongside older female or a buck reconsider their strategy and pay a greater due to observation and their natural curiosity.
However, although I cannot quantify these reactions, it appears to me that they are more confident in male presence than in older female presence.
The older female has higher stakes (she is possibly a mother and therefore more vigilant and less calm than the male as well as unlikely to defend the younger female if it were necessary and if bucks, indeed, ever did so).
While with both older female or male, the young doe seems to wish to leave but then she stays to observe us when the other individual does not follow her lead.
However, with the female she performs the observation from a greater distance and does not reduce her rate of vigilance while with the male she sometimes even keeps feeding and allows a far closer approach (we do not approach but the distance between us and the deer are smaller due to reasons like infrastructure and encounter conditions).
With the female, both females retreat some distance and then stop upon the decision of the older individual.
With the male, they do not retreat and the male can even make a step in our direction.
It makes me believe, personally, that the young female relies on the buck for predator defense while with the older female she follows her reactions and perhaps considers the risk dispersal scenario where two individual group divides the total predation risk by half.
***
I have also described an incident were I suspect a fawn was grazing together with a buck and a female (on 8th July) although I think the female was not the fawn’s mother.
She could have been the fawn’s aunt or grandmother etc. and the buck could have been the fawn’s father.
The description can be read in the post, ‘Roe deer males – higher parental investment than currently assumed?’
***
It is the middle of July and one of the bucks that hold a territory in a specific area is more often seen foraging together with a younger female than alone.
I have observed him alone once and with the same female perhaps 4 times by now.
***
This grouping behaviour apparently extends over a vaster scope because presently I have learned to tell approximately where specific individuals/group reside (home ranges).
On most if not all of those ranges (I have not quantified my observations and I am afraid to provide false information) the adults (and yearlings) are seen in pairs or small groups about as often as they are seen alone.
Notes by Ieva 