In this post I will be referring to observation I made tonight.
However, tonight was simply the night I became conscious of a pattern in one family’s behaviour.
This is a rather special family.
Their range is rather… well, crappy, due to human intervention.
But they seem to be resourceful and innovative, and courageous.
If anything, this is the one non-traditionalist beaver family in our area (although I believe there is another one which might be related to them; see Beaver observations (autumn, winter, 2023/24) – related families with shared behavioural traits?).
In fact, despite their challenging range (quite cleared of woody vegetation, grazed by cows, fenced, frequented by humans etc.), on Apr 16 I got to establish that they probably had had two kits last year while the rest of the families seem to have only one surviving kits.
This makes me wonder whether the daring conquests of faraway inland shrubs and even the journeys to distant roadside fruit trees this winter (travelling at least 700 m overland and also up a steep slope and through private garden allotments which must have plenty of human smell to them) were the result of a successful reproduction.
I believe that the family had one older subordinate who dispersed this spring and thus they would have made up a unit of 5 beavers on this difficult range.
They had to get creative but they were also highly capable of being creative, apparently.
Tonight I encountered this family in one of its typical locations which is easily accessible to me, as well, because it is comprised of riparian forest (considered a park, locally) and an abandoned meadow where people go for walks.
On Apr 16, after a windstorm and a sharp drop in temperature (see Unusual night observations after a windstorm – beavers, roe deer, tawny owls (Apr 16, 2024)), I was surprised to find all the beaver families located together (while usually they forage in a scattered manner quite often if not mostly).
After that, I began paying close attention to how this behaviour develops.
This is likely the reason why I noticed that the particular beaver family has been hanging out a lot in this area which is probably of the poorest quality on their entire range.
For most part, there is no riparian vegetation apart from wilted grasses and the few shrubs and trees have not been touched by the beavers.
Beavers, especially, the young ones in this family are frequently encountered in a straighter stretch of our otherwise meandering river where water is deep but where the banks are bare of vegetation.
There are some aquatic underwater grasses but I do not suppose they have not fully revived yet (i.e., the beavers are not hanging out there to forage on this vegetation).
Moreover, the same type of aquatic vegetation can be found on their range in shallower sections where they would not have to dive for it.
I was rather confounded by this family’s behaviour.
They also forage equally in the more sequestered parts of their range as in a section which they perhaps discovered during winter floods and where they have to travel inland (> 20 m) to forage on shrubs.
It seems that this family is characterized by curiosity and a desire to explore and to challenge themselves.
While keeping safe, they are not restricting their activity to traditional foraging patches and they perhaps enjoy out-of-ordinary beaver-feats.
As I suspect that those were last year’s kits hanging out in the straight stretch of the river where there was nothing to be foraging upon at all, I started wondering about this behaviour.
During winter, these juveniles still seemed to keep close to dens where water is also deep.
At least, in places where I think there are bank-side burrows (in this area, beavers do not construct lodges), I often encountered smaller-sized beavers and I suppose that they were not straying far from den while it was cold and while the parents often had to travel far to forage due to scarcity of resources (covered in snow, difficult to access).
When I began considering the last year kits’ behaviour after the warm weathers set in, I have to conclude that they generally tend to be found in sections where water is deeper (unless with an adult).
Perhaps this is a safety measure.
Even if those are not all den sites (some of these sections are unsuitable for burrowing or I cannot imagine beavers choosing to den there because those are areas of high and noisy disturbance during daytime), the juveniles might still be wary to forage and to travel extensively along longer, shallower stretches of the river without adult supervision.
This behaviour is apparently bound to change at some point during their development because yearlings (their older siblings) foraged often in shallower spots while the rest of their family was hundreds of metres downstream or upstream.
I do not always encounter only juveniles in these segments of the river which are deeper but not offering much of foraging, nor rest (in some areas, the bank is almost horizontal and there are no comfy spots for grooming, allogrooming etc.).
When I meet adults there, they are quite often in company of other family members.
Perhaps the adults sometimes check in with the youngsters if they have not ‘heard from them’ in a while.
However, I also wonder if beavers might be visiting these deep-water, straight-channel features on their home range to play, exercise etc.
The two juveniles in the family I have dedicated my post to probably engage in play and the river segment where… well, beaver bottom does not hit river bottom easily and where some speed can be gained, is highly suited for some physical activities of the exercising/play context.
I have seen many beaver family wrestling videos (both on land and in water).
Perhaps it can be joyful to wrestle in deeper water which is a different experience compared to on-land wrestling.
I have not seen any beaver speed-swimming videos, however.
Still, it is likely that our knowledge of how beavers play is limited.
I believe that the two juveniles in this family are using the long, straight stretch of deep water for play that is less sedentary and more mobile (e.g., beavers can wrestle in one spot but other play activities might involve swimming and diving which cannot be achieved in shallows or in restricted space.)
Still, I wonder if adult beavers might be in need of similar activities (because those have not been only juveniles I keep meeting in this sector) which might not be considered play as much as they are considered exercise (although I should like to point out that adult beavers play, as well).
Many of beaver foraging movements involve holding head at strange angles (even if beavers are probably adapted to such angles) or holding head down, or sort of crouching in one position for a long time.
Beavers are not endowed with long limbs that would allow them to stretch (the way felids, canids do) relieving muscle tensions.
As a result, adult beavers who have been foraging might include some exercise in their post-foraging routine (before grooming) in order to attenuate muscle tension.
This particular family might be a perfect example for such need because not only they perform the traditional beaver foraging motions but they also travel inland much further and they must drag the branches all the way back to the waterline.
Swimming and diving is an energetically costly activity.
However, the simple act of propelling oneself forth in one push to ‘slide’ far underwater or half-submerged cannot be altogether that costly but this act (especially, when performed in deeper water over straight line) could reduce muscle tension.
Beavers are master-swimmers and I suppose that this ‘long stretch’ of river could be covered in one dive.
At least I know that after a brief exercise of breaststroke swimming style, the pressure of water against the body results in a physical sensation of lightness and almost ‘flightiness’.
It might be the effect of water predominantly that ‘strokes’ the muscles and massages them that could benefit a beaver (with little effort because the beaver just have to propel themselves slightly relying on inertia augmented by their streamlined physiology).
However, it could be combined with some motions such as twists or underwater rolls to let the water ease tensions in specific muscle groups.
As a poorly-stretching species, beavers might use some swim techniques to ensure their muscle health.
This family might have established its own playground/exercising pool.
***
In the last week of April (ca. Apr 28) I also observed a beaver foraging on the shore of this straight stretch (which I believe was a new behaviour this season due to the latest active growth of riparian grasses and forbs).
The beaver was apparently eating either grasses or goutweed and the foraging occurred on a ‘buffet’ type of sandy elevation which is located between the water and the river bank itself.
The bank is almost vertical there but the gap between the bank and the river is about 0.5 m wide.
It must be a nice and safe foraging spot because the beaver hardly needs to leave the water.
Unfortunately, I suppose it will only be available (attractive) while the forage is of recent growth and, soon enough, the stretch will be, once more, only suited for swimming activity and not much else.
Notes by Ieva 