On March 20, I was sitting in an observation spot by the river when I heard a beaver slapping its tail against the water slightly downstream.
I was somewhat surprised because I was sheltered from view, the wind was blowing in the upstream direction (I would rather smell the beaver than it would me) and I had been very quiet for at least 15 minutes.
There was another splash duly followed by a third.
I became curious.
I have written previously that I do not believe tail slapping is only used as an alarm signal to protect the family against predators.
I believe this behaviour has a range of communicative intent, including communication between colony members but also communication with other species.
It is often difficult to tell these two apart because the presence of another species is not always evident to me.
If it is evident to me, then I am also a factor or possible disturbance because I am close enough to be able to observe all the species present.
Thus, under circumstances when I have not been immediately present (the event has occurred outside my field of vision) and no suggestive sounds have reached me (e.g., roe deer stomping), upon later examination, it is not conclusively possible to eliminate the option of there having been someone else who enticed the reaction from the beaver and who left no traces (as opposed to the beaver producing the splash for purposes unrelated to other species).
I became curious and, stealthily, I began approaching the site.
The snow is gone and therefore any examination of footprints was futile as the riverbank is rather covered in down-pressed last year’s vegetation.
I could not see anybody (not even the beaver) and, being somewhat sleepy, I simply sat down to induce a false hope in my body that a nap was due.
After about a minute, I suddenly heard a loud hiss in the middle of the stream and floating downstream away from me.
Beavers do not hiss (at least I have never heard them hissing, nor I can imagine that a ‘beaver hiss’ would have such specific quality).
It was a mustelid-y hiss, and as there are American mink living in this river, I assumed I had been hissed at by a mink who had probably also been the involved party in the beaver communication event (as only about 4 minutes had elapsed between the slaps and the hiss).
I believe that beavers and mink are mutually tolerant neighbours because last year beavers raised their kits in a bank den (under roots of trees) that I am quite certain was also used by mink (although I cannot tell whether the mink used it as daytime shelter or a denning site, or maybe rested there very briefly taking a break during active foraging periods).
However, apparently, the beaver had reacted to the mink’s presence with a tail slap.
Tail slap is normally considered a defensive act.
A mink might be perceived as a predator. Theoretically speaking, it could pose a threat to newborn/extremely young beaver kits in the den.
Currently, the mating season is over and the breeding females in the colonies are probably pregnant.
Hormonal production in both the mother and father might induce heightened anxiety/aggression levels leading to ‘warnings for the future’ (e.g., responding not to the current family status but already exhibiting increased vigilance for future threats to the kits that are yet to be born).
I find it not very likely, nevertheless, that the beaver slapped its tail because it was alarmed by the mink (or even because it wished to intimidate the mink).
Unless the mink truly startled the beaver, for example, by touching it while swimming nearby on which occasion the slap could have been an expression of surprise.
I find it unlikely due to the following reasons:
- Beavers apparently allowed mink near the natal den during summer and therefore if the beavers watch out for mink, it is only during a short period;
- Beavers have tail-slapped in response to other species that do not pose a predatory threat to any individuals in the colony (roe deer) but which could be viewed as competitors or a nuisance (or, as I will discuss later, neighbours).
These instances where beavers have slapped tail in response to other species that are not necessarily predators have made me wonder what other communicative messages are conveyed through the tail slapping act.
Case could be made that beavers do not like other species (with whom they share the river channel or the riparian habitat) to intrude into their personal space or (with regard to roe deer) to forage/meddle where the beaver was about to forage.
I suspect I have heard beavers slapping their tail in response to ducks, as well, who might obstruct passage or who might produce noise the beaver dislikes.
Essentially, I believe that it is a matter of having neighbours.
Thus far, I have discussed the issue from a negative perspective (why beavers might be annoyed with their neighbours) but I believe that the tail slap could be used also in a positive way.
Firstly, it is interesting to consider what exactly any species considers to be their home, their territory, their possession.
Wildlife does not reside on plots where they are almost the sole actors.
Within anybody’s homerange, there are other species.
Some might be microscopic or quasi-microscopic (too small to bear much influence or to even be noticed).
But others are larger and whether they interfere or not with the individual’s particular activities, it is difficult to ignore them altogether if their paths cross with the individual’s path frequently and/or close enough.
It is known that there are dominance relationships, for example, between different deer species or between different carnivores.
Some species might exclude others or facilitate others, but, most often, they attempt to each find their own niche, i.e., to stick to a lifestyle and resource use that allows them to avoid unnecessary competition.
Beavers constitute a species that probably has to interact with many other species or at least tolerate their proximity because beaver dams and ponds are wildlife magnets.
Many animals seek beaver-transformed habitats to travel (along dams), to cohabit (in lodges/dens) or to forage (in ponds) (see, e.g., Nummi, P. et al., 2019).
As the beaver is apparently exposed to encounters with a great number of different species, I suppose the beaver should not have developed some type of disfavour toward a interactive lifestyle.
The beaver might sometimes react with disdain if the beaver is altogether bumped into, restrained from its choice foraging patch, blocked passage or if another animal is damaging the beaver’s constructions.
However, I also wonder whether the beaver would not have evolved some behaviours that benefit them from these interactions.
It might be important to note that in the habitat I am describing, there are no beaver-built structures and the overall perception of the habitat by the beaver might be different because the river channel and the riverbank are shared and none of them have been actively formed and modified by the beaver.
Namely, the beaver might have different attitudes when the beaver encounters other wildlife ‘on their own turf’ (in their pond, near their lodge, near their den) vs. in the general habitat that is defended by the beaver as its territory (against other beavers) but that does not have many sites which might be perceived as territories within the territory.
Namely, many territorial species that exclude conspecifics from an entirety of an area also have some core areas (usually, natal dens and the vicinity of natal dens) that they defend even more intensely and that they might mark or keep watch over etc.
Meanwhile, non-territorial species would also guard, for example, dens or would discourage others to use their key foraging patches.
The perception of importance of different areas within the home range might be thereby different between territorial and non-territorial species.
Territorial species might be better aware of the scope of their home range (its boundaries) while non-territorial species might be better aware of which particular sites within their home range are essential to them to the point they would be prepared to initiate a conflict over them despite their otherwise non-territorial behaviour.
Perhaps beavers, in their interactions with conspecifics as well as with other species, are developing both types of appreciations.
Namely, by patrolling and scent-marking territory boundaries, the resident beaver would be aware of the size of their territory.
However, the non-related conspecific must be excluded from anywhere inside of the territory and thus the territory is not further divided into subunits of contrasting importance.
Beavers also have to react to predators.
Predators cannot be excluded from beaver territory.
However, beavers would take extra effort to exclude them from the natal den and possibly other types of dens/burrows/lodges.
Thereby, the sense of a home centre might appear.
Also, as beavers exhibit the strategy of carrying their forage down to the shore or near the den/lodge to consume safely near the water, beavers might differentiate more greatly between these secure sites vs. the general habitat.
Meanwhile, neighbours (such as roe deer, ducks, mink) who might or might not be predators/competitors also allow for the opportunity to experience frustration/dominance/protectiveness toward areas that are otherwise not deemed of higher territorial value (territory, den), nor they are necessarily the ‘safe sites’ (central foraging sites on the edge between water and land).
For example, if a beaver wishes to forage on land but a few roe deer are hanging out there presently and if the beaver is annoyed or intimidated by their activity, the beaver will evaluate the significance of the specific foraging site and the beaver will also assess their willingness to try to dominate the situation or to abandon the intent, or to tolerate the neighbours in a collective foraging setting.
Such evaluations and assessments would form a psychological map of important vs. less important areas within the beaver’s territory and this map might be rather intricate as the beaver meets many species along the gradient of affability vs. intimidation (most being neutral).
Any foraging site or segment of passage might be fitted against several neighbours and the cognitive/emotional states that they cause.
In areas where the beaver clearly dominates all or most species and where other species are not met very closely, are not very loud or otherwise attention-provoking, the beaver might not develop such subtle maps.
But in areas where the beaver interacts with a variety of species, these neighbourly relations might result in a more thorough of understanding of the beaver’s resources, opportunities and they might lead to a cognitive flexibility as the beaver must adapt its behaviour and decisions to those of other species.
I believe it is a clear benefit.
While the beaver might have to invest in emotional/physical reactions, they also become better aware of what is available to them and how the availability/quality changes.
For example, if the beaver has been foraging in some spot for many years but over the last years the quality of the foraging patch has decreased, the beaver might develop a less strong response to presence of other species in this patch or a denier opportunity to visit this patch.
Such modifications in favouritism are not necessarily cognitive (although they might be).
If the beaver experiences a state of contentment and wellbeing while foraging somewhere and if the beaver’s body experiences nourishment and relaxation, the beaver will develop an attitude toward this site which is rooted in long-term experiences of certain physiological and psychological states.
If the quality of this site diminishes, the beaver might experience other states but these experiences might not be recognized by the beaver as quickly if ever (because the attitudes produced by long-term experiences also tend to shift in long periods and the beaver might be unaware that the shift is occurring – the beaver would naturally and gradually adapt to the new attitude without necessarily having noticed that it changed at all).
Meanwhile, reacting to dynamically changing conditions involving many other species is a more cognitive state and if any attitudes toward any territorial sectors might have changed, the beaver would be likelier to become aware of it.
The beaver would be granted an opportunity, for example, to consider intervention in order to improve the quality of some depleted foraging patch or they might move dens etc.
However, I cannot help but believe that the beavers also sometimes slap their tails to simply greet their neighbours.
Such greetings could feel empowering and I have already written about the possible role of expressing pride in one’s relations/possessions without placing oneself in true danger from the perspective of protective feelings (Beaver observation (Mar 13, 2024) – last year’s kit protecting mother?).
Only, rather than feeling protective, the beavers, in the circumstance of issuing a greeting, might express dominance as the underlying attitude.
Beavers might also slap their tails to teach other species how to behave around them and their property.
But I also think it might be fun for the beaver.
I think that many species predominantly gain a sense of self-identity based on how the world responds to them (objects, prey, predators, competitors etc. but also family, social group, allies and allied species), what impression they create in others.
Many of these interactions can be dangerous and it might be important for an individual to attain self-awareness of their dominance/strength/size in the context of safe interactions.
Beavers typically live in family groups and the responses by other family members toward the individual are objective but they are also influenced by the role that the individual plays (parent, offspring, sibling).
The individual might benefit from responses outside of these family relations and the individual might benefit from evaluation of their form and status by someone who is not a predator/competitor but just a neighbour.
Finally, we do not know to what extend animals experience that they share some resources.
Namely, we do not know whether animals perceive something is being theirs or not being theirs and whether collectively used resources are perceived as ‘mine that I also allow you to use’ or ‘ours’.
The concept of ‘ours’ is rather more abstract because it involves the grasping of a group as a whole rather than a combination of individuals.
For example, a family can be thought of as comprised of me, my mom, my dad and my sister but it can also be thought of as comprised of ‘us’ in a more generalized manner and such generalized perception would already engage the abstract concept of ‘family’ (not merely what it means to be simultaneously a son and a brother but what it means to be a family where other individuals have relationships outside of those that I have).
The river is inhabited by many species and while parts of the river are considered their territories by the beavers, it must also be clear to the beavers that they do not belong entirely to them.
Do beavers have a sense of the river (as well as its riparian habitat) being ‘our river’ shared by beavers and mink, and ducks, and roe deer?
Dominance hierarchies and rules of interactive conduct probably shape this type of identity and collectivism.
If one has a place within a structure and one abides by it, then one must perceive a structure exists.
Perhaps these greetings that sometimes might appear aggressive, intrusive or otherwise unlike our greetings, are, in fact, testimonies to one’s place in this structure of a certain community.
They might be translated into such statements as, ‘I am this big and this influential in our shared home and I recognize that you are this big and this influential.’
Sometimes species might even resort to a certain cheekiness in order to affirm their presence and to entice a response to their presence.
Thus, through neighbourly interactions, individuals might position themselves within their habitat on a scale not of mere sites (e.g., homesites, foraging sites) but on a scale of belonging and collectively expressed identity (a far more abstract scale).
Through gathering responses from many different neighbours, they might develop a perception of why they are within their ecosystem.
For example, each neighbour reacts to them according to their own size.
Thus, some neighbours might be bigger and some smaller.
By gathering reactions from several neighbours, the individual might begin to understand how big or small they are not respective to their conspecifics, their social group, their competitors etc. but respective to their home and its life forms.
The structure here is that of a space of living, of an ecosystem, a habitat.
If animals were seeking such understanding actively, I should say that they are philosophers who inquire, ‘Who am I and what is my place in this world?’
The beaver likely dominates most of the riparian species here in our river.
Therefore, if the beaver in the everyday greetings with its neighbours usually comes across as the strong, as the powerful, as the confident one either dominating others to their will or being able to tolerate them on its own terms, the beaver might truly feel (and be) the owner of the place, and the beaver’s sense of its home might become more intense and all-encompassing than the sense of the home in other species who have to give way, to adjust etc.
Perhaps the beavers who apparently do not have a great many objections to other species near their ponds, dams etc., have gained this attitude not through necessity but through self-identification as the hosts of these habitats and structures.
It is the benevolent stand of a mighty and proud homeowner who instead of guests and tenants, has other type of neighbours living not adjacent to but inside of its home.
References
Nummi, P. et al. The beaver facilitates species richness and abundance of terrestrial and semi-aquatic mammals, Global Ecology and Conservation, Volume 20, 2019, e00701, ISSN 2351-9894, https://doi.org/10.1016/j.gecco.2019.e00701
Notes by Ieva 