Today around 9.30 am we (my dog and I) encountered a roe deer buck who was standing amidst a slope in the riparian forest bordering a hay meadow (the meadow was between the forest and the river although this is rather irrelevant to the incident).
It was the largest roe deer buck I have ever seen. It was huge.
Only yesterday we met another male (a local buck) who ran right past us (Roe deer observation (Mar 26, 2024) – territorial pressure), and I could now compare the sizes of these two males.
The buck we met today was probably younger (judging by its antlers and overall smooth appearance) but it was by at least one third larger than the buck we met yesterday.
This might contribute to the theory that there are two roe deer species in the Baltics, including Latvia (see Siberian roe deer in the Baltics – an additional cervid species in the European Union?).
Recently I read that roe deer in Central Europe have adapted to the open habitat landscapes and foraging conditions.
Meanwhile, in Latvia I often observe roe deer living in riparian forests who clearly dislike crossing large open areas while other roe deer do not seem perturbed by the open situation and these deer do not have as extensive forest cover on their range (see Two roe deer types – open habitat type vs. forest type).
The forest type deer also seem considerably smaller (perhaps it is more beneficial for them to remain small in order not to increase their food intake and also to be able to hide efficiently).
I cannot attest to our roe deer having uniformly adapted to open field habitats and I believe that perhaps in eastern-northeastern Europe where there is still considerable forest cover, the forest roe deer have retained their size and behaviour.
If these forest roe deer, indeed, live sympatrically with Siberian roe deer, the attachment to forests and the subsequent lack of adaptations in morphology and foraging behaviour might have further contributed to niche separation between these two species.
The forest roe deer might have an advantage because the buck I observed (who was gigantic) clearly could not sustain himself in just any habitat.
He was far too large for the riparian forest and I could spot him easily.
Such large bucks would fall prey to natural predators or hunters more often than their smaller, stealthy compatriots.
Also, they might not be able to get enough energy from the forest foods and the forage available close to forest.
They might need open fields and larger ranges and their anti-predator strategy might involve grouping up and shared vigilance as well as blending in forests that are perhaps of a different structure (that can conceal them better due to presence of large trees, thick shrubs and due to the vastness of the forest expanse vs. the narrow corridors of riparian forests etc.).
The buck was also lighter in colour and often the roe deer in more open habitats seem lighter.
The riparian forest roe deer can be darker (the male we encountered yesterday was dark brown).
These behavioural, metabolic, morphological and social differences might have led to a niche separation encouraging the forest type roe deer to stick to their ancestral habits.
Thusly, I suspect that not only there might be two roe deer species in the Baltics but also the forest roe deer (Capreolus capreolus) might be more ‘authentic’ (having retained much of their early Holocene behaviours and adaptations) than those found in Central Europe who have perhaps evolved a lifestyle that is intermediate between open field/forest roe deer phenotypes.
Perhaps our European roe deer should be granted a subspecies status.
Be as it may, I have not finished the story of our encounter with the giant.
The buck was standing half-slope as I mentioned.
Typically, if any roe deer are spotted on that slope, they would either run forth through the riparian forest or they would ascend and vanish into the adjacent apple orchard.
That would be the customary escape behaviour of the locals.
I suspect that this buck was not a local (I would surely have remembered meeting him and I believe I am familiar with the residents) and that this buck was trespassing (or, to term it more lawfully, dispersing through another subpopulations range).
The buck did not take the route usually selected by the locals.
Instead he chose a more dangerous path.
He turned and ran quite close to us, crossed through the thin grove of trees by the river and then plunged into the river to swim across.
Herein lie several cues that he was not familiar with the terrain and that he was avoiding bumping into the local male.
One of the cues refers to information I shared in the beginning of the post.
It was around 9.30 am which during this season is the time when the roe deer have concluded their morning foraging bout and have sought out shelter to rest.
The buck might have timed his foray in order to limit the possibilities of encountering any active locals.
Secondly, the buck obviously wanted to reach the river although this meant he was running toward us and not away from us.
I believe that he had arrived by crossing the river (and, indeed, that would be almost the only route he could have taken, especially, if he came from an open field population).
He might have crossed the river relatively recently and he might have felt more secure he would not bounce into any local bucks (while he could not be as certain where the local deer could have been located at the time on this side of the river which he had not explored yet).
The supposition that he was not a local was also revealed by the fact that he was probably unfamiliar with the terrain because he did not choose to cross the river where it was shallow (and where locals would have crossed).
He plunged into one of the deepest sectors and he ended up on the other shore which was very steep and overhanging.
He was forced to return into the water and swim some more to reach a spot where he could eventually climb ashore.
Locals would have been better advised where to cross without having to swim (and, indeed, there were crossing spots where he would have easily waded, monumental as he was) and where it was easier to get up the bank.
When the buck had reached the other side of the river, he shook in order to ‘dry himself’, and it was a magnificent sight.
Then he looked back at us and, in a rather dignified manner, walked off.
It was interesting that this buck seemed young to me although I cannot guarantee that he was.
However, I believe I am right in assuming that he was a youth on dispersal because nobody would have been able to force a territorial male of this size out of his own range.
He was clearly at competitive advantage but he acted with plenty of caution and also perhaps on impulse rather than thorough assessment of the situation.
(Which might suggest that young males are wary of older males even if they are much larger because they lack experience or because they still have not abandoned the socially gained impression that elders have to be respected. This could be the result also not merely of age difference but of having been/not having been territory holders as well as having had/not having had mating experience. Another factor could be the antler size vs. the body size because while the young male was big, his antlers might have been smaller or of the same size but definitely less elaborated than those of the older males. Perhaps antler size and/or structure determine the outcomes of territorial/mating-related confrontations.)
While it would seem that smaller individuals are likelier to be pushed out from established populations, I have read some scientific references (unfortunately I cannot remember in which publication) that in the red deer species, for example, often larger, healthier males disperse.
Perhaps these males are not content with the population density and/or if they have been born in a dense population, they might not be able to obtain enough forage to meet the metabolic needs for someone of their size.
This could have been the case also with our male.
I believe that he might have been born perhaps two years ago (because his antlers were developed to a greater degree than I have observed in yearlings but his antlers did not seem as developed as those in mature bucks, either).
Perhaps he was born in a relatively dense roe deer subpopulation and during his first year of development he could abide by the forage availability.
But as he matured, it is possible that he gained confidence to attempt dispersal which was prompted not by competition because he was so gigantic (although he could have been wary of the local bucks to an unsubstantiated manner due to lack of experience) but rather by his high metabolic needs that drove him to search for habitats with greater forage availability or a lower roe deer density.
The buck did not appear to have suffered malnutrition.
One of the reasons why I suspected he was a youth – his coat was glossy, he had no scars; he just looked like a model on the cover of some roe deer teenager/young adult magazine.
In any case, he would not have found such habitats on this side of the river.
While he might have been able to outcompete the local males (who despite being older, are much smaller), he might not have been able to satisfy his metabolic needs in this area made up of patches of riparian forest, small hay meadows, a couple of small orchards and a bunch of private garden allotments (many of which are fenced).
Similarly, he might have been able to woo females if roe deer females prefer larger bucks but his reproductive success might have turned out to be low because the females, as well, are much smaller in the riparian forest habitat and they might not have been able to carry his offspring and to give birth without injuring themselves or dying.
I hope that this magnificent specimen has better luck on the side of the river toward which we inadvertently herded him back.
I also sort of hope I might meet him again (in another area) because he was… enormously beautiful.
Notes by Ieva 