Beaver observation – Jan 10, 2024

This is not a post to discuss any theories but rather to write down an observation which I thought was interesting and I wished to share.

My observation involved three beavers that belonged to one family.

I believe those were 1 kit (born in 2024), 1 subadult (perhaps born in 2023) and 1 adult (mama or papa :).

The observation was made at around 3.30 am in a riparian forest area.

December ended in temperatures dropping below -15 and even -20 °C.

Then, very suddenly, temperatures rose (on Jan 9) keeping around zero or even reaching above zero (< 5 °C).

Thus, we had some -15°C temperatures on Jan 8 and then zeroish temperatures the very next day.

However, on Jan 9, beaver activity was absent (at least I did not observe any beavers) and I wonder if beavers are perhaps less flexible in reacting to such sudden fluctuations.

For example, I have read (see, e.g., Campbell, R. et al., 2012) that beavers have a more difficult time adapting to changing weather and unpredictable weather.

Beavers appear to be a species that relies on long-evolved reactions to the surrounding environment that are perhaps rooted in genetics and morphology rather than they are rooted in behavioural plasticity.

As far as I understand, if beavers are subject to some weather extremes, they would cope better if these extremes were not abrupt and replaced by other extremes but, for example, if there was a cold spell preceded and followed by regular weather (historical average) beavers would do better compared to our current weather patterns where one week it can be extremely cold only to shift to extremely warm weather in the very following week which is then again followed by very low temperatures etc.

In fact, proper seasonality and cold would not affect beavers as greatly (apart from kits) as such fluctuating, unpredictable weather which demands for quick responses.

I am mentioning this because the family that I observed was the first beaver family I saw out and about after the dramatic change in weather (implying perhaps that they had spent more than week largely in their den with limited food resources and limited physical activity as well as nothing much to explore).

I think that perhaps beavers also make their estimates as to when they should venture above ice regarding the water temperature (and not just air temperature) predominantly as well as they might assess the transparency of ice (how much light comes through) that could indicate the conditions of the river.

Maybe there is some significant difference between how the ice looks when it is vs. when it is no longer covered with snow (although I should assume that melting ice becomes denser and compacted).

These traits do not change as quickly as air temperature does.

Air temperature can rise more abruptly while water temperature remains more stable.

Besides, if beavers react to light conditions, it might noted that the moon was new on Jan 11.

Ice does not melt during a single warm day, either. However, ice probably is beneficial for beavers while it can carry their weight as it can allow to move around without swimming which is an energetically more demanding activity, especially, during cold weather.

I observed them in a river segment which is characterized by a turn in channel by almost 90°.

As a result, water is sort of slow-flowing there and ice formation was denser on both sides of the river although in the middle of the river, the water was streaming forth already at a melt-power speed but it had not yet truly crushed its way through the ice in order to start floating it along massively.

The beavers were observed on that ice.

I previously mentioned that thick ice might perhaps suggest to beavers that it is still cold outside and this portion of the river had thicker ice than other segments but I do not know specifically where the beavers den in that area (they den in burrows).

Certainly, the conditions observed on Jan 10 were excellent regarding travel along shoreline ice which had not yet parted from the bank.

I approached the river from the main trail by taking a smaller, narrow trail which leads to a spot where people can sit quietly and watch the river.

On this side, the bank is steep and rather repleted in resources that beavers might prefer.

On the other side, there are shrubs and the bank would not take as much effort to climb.

Two of the beavers (the kit and the adult) were observed on the other side of the river, right at the bend in the river.

The third beaver was on the ice in the middle of the river opposite to the end of the trail.

In fact, as I reached the end of the trail, the beaver was in front of me – some mere 5 metres ahead down the bank and on the ice.

It was sitting on a large chunk attached to my side of the river but bordering with water torn open by the stream.

As I had not made an attempt at stealth and I was highly audible, visible (and smellable) to the beaver, I thought at first that it was not a beaver at all but some beaver-shaped log which has ended up washed out on the ice (although it seemed strange that the log would be washed out against the stream but rivers have their whims and ways).

Thus, I did not appropriate my conduct but the ‘log’ kept watching me.

I noticed another ‘log’ (which I knew was a beaver because I saw it moving and because it was located in a spot where beavers are frequently seen) downstream on the shore ice of the opposite bank.

As I listened in, the further beaver was chowing on something that it had probably collected on its shore and that it had brought down to the waterline to consume snugly.

This beaver was an adult.

It was sitting right on the verge of the ice chunk and eating.

I watched the beaver and while I was doing so, the ‘log’ in front of me turned, slipped into water and was proven to have been a beaver, as well.

I was rather astonished because this beaver certainly had known I was there and it had apparently stayed where it was in order to observe me (because there was no other reason of staying – there was no forage and I hardly believe that the beaver was desperate for me to move off so that it could climb out on this shore as this side of the river offers scarcely any forage compared to the other side).

The beaver closer to me had been big (bigger than a kit, surely) but perhaps not large and I thought it could have been a subadult because it did not make a splash with its tail, either, in order to alarm its family.

I wondered if this beaver was a subadult who had been bored to death during the cold spell in the den and who was more interested in getting in touch with what’s new than foraging and being highly responsible (e.g., prioritizing its survival over its curiosity and feeling at all times obliged to put family first and to warn them of threat at any cost and under any circumstances).

Later, considering all of its behaviour, I also thought that perhaps this beaver was reaching the stage in its development where it was growing detached from its natal family unit and pondering striking out on its own (exploratory behaviour, weaker ties with other individuals in the colony).

Shortly thereafter, a small beaver flopped up on the ice right beside the adult beaver downstream.

I am using the word ‘flop’ which does not do the justice for the elegance with which the beaver got out of the water and onto the ice that was slightly elevated above the water.

Perhaps I should have written ‘sealed up’ (in reference to pinnipeds).

The timing was just about right for this individual to have been the same individual who had ‘logged’ me from the ice in the middle of the river.

I thought I could have been wrong regarding its size and maybe it had been way smaller (as it appeared now that it was beside the adult).

However, those had been two separate individuals as will be explained later.

Also, I find it difficult to believe that a kit would have acted in as nonchalant manner as the beaver near me had.

I suppose that a certain degree of ‘coolness’ and ‘dare-devil’ attitudes belong with subadults who have experienced enough and who are large as well as skilled enough to know their risks and who do not have anybody depending on them, either.

The small beaver (I should say it was a kit if I ever saw one) first tried to forage neatly beside its parent (the adult beaver).

Apparently the adult had dragged enough food for the both of them.

But the kit was restless and soon it walked in half-circle around the adult and then returned to the waterline and then walked off a bit again and then returned again and altogether fidgeted around.

I thought this was rather interesting.

The kit, too, had emerged from the burrow after weeks of reduced food availability and ‘mighty cold’ (compared to the winters of last years, not to the historical climate of Latvia).

Moreover, I have never truly observed any food caches made by beavers on this river.

However, during cold spells they reduce their above-ice activity (as I have been informed by the relative lack of beaver trails in the riparian areas during periods of freezing temperatures).

Then where do they obtain their food?

My guess is that perhaps they store also some forage in the burrow systems which I suspect are extensive and also ‘ancient’ here.

As I had read that beavers are likelier to cache food when they have kits (which might imply that kits are the ones whose survival depends most on cached resources and who might be affected the most when resource availability is low during winter) and I also had read that beaver kits form the social group that is most impacted by cold winter weather, I found it astonishing that this beaver kit was not set on foraging (like the adult was who had not even stirred from its ‘seat at the table’) and that it was apparently following in the footsteps of its older sibling and stretching its legs and prancing around.

It was adorable to watch the tiny fellow or lass as the kit just did not know what to do with its… frustrated investment

I do not suppose it was actual physical energy that the kit tried to dispose of (because, as stated above, cold weather can be precarious for kits) but perhaps there is a certain amount of cognitive challenged needed by an individual which cannot be satisfied while biding the time in the underground burrows.

Maybe this insatiable curiosity is more pronounced after the kits and subadults have reached a certain age and before they have truly become adults, territory holders etc.

Perhaps after some critical stages of development have been accomplished, the subadults find it physically more impossible not to satisfy their need to explore (both the environment and their own capacities) than to not satisfy their need for food.

It should also be mentioned that this might have been the first substantial freeze-over in the kit’s life (temperatures prior to December were below zero (ca. -5 C°) but the current was very strong in the river and ice did not form much, only in narrow bands along the slower segments.

Meanwhile, it might be currently the beginning of the mating season for beavers and perhaps the adult has to take care of its fitness due to the hormonal production which is why it focused on foraging.

While the kit was still romping around its parent (but not daring to travel too far, either – it never retreated from the adult more than 3 metres), another beaver got up on the ice opposite from me, and I believe it was the same individual I had observed ‘playing log’ previously.

It was very curious why this individual would act this way.

Perhaps it was checking whether I had left.

I will mention again that I was not in its way between some highly desirable resources and its current location and I hardly believe the beaver would have climbed on this bank if I left because it is very steep and I have not seen beaver prints there for a long time.

I suppose that this subadult was attempting to make sense of what kind of an animal I was (I was with my dog, too, who was sitting quietly beside me and observing).

I find it difficult to believe that the beaver had to climb onto the ice to check us out because I was not being silent.

I had spoken to my dog in not too hushed a way and I had moved around (even stood up).

Still, this is a place where many people and dogs walk… during daytime.

But not at night.

I suppose that the subadult beaver found us somewhat extraordinary and strange, and it wished to understand what we were in its world.

Perhaps it suspected we were not threatening but did not trust its judgement fully, either.

The beaver remained on the ice (once more, about 5 metres from us) for several minutes, not foraging, not doing anything but probably sniffing and listening.

I did not adapt my behaviour much, either, and so we watched one another.

By and by, the beaver quietly slipped back into the water and, this time, it make a very unconvincing splash with its tail.

Apparently it had figured out we were a human and a dog and reacted accordingly but it had probably also determined that we were not a huge threat and the alarm was very vague.

Some beavers would splash their tails over and over again with huge vigour – but this would also happen during times when the beaver has not gone through a cold spell (it has more energy and maybe it does not worry that the cold might return and that its energy has to be spared).

I would assume that this served as additional evidence – the beaver in front us had not been a dominant adult.

This beaver hardly slapped its tail and the sound barely carried but apparently it had reached the other two beavers downstream.

The adult beaver did not react at al but the kit immediately dived into water.

It might be worth noting that the kit dived into water before assessing the situation – I believe it fully trusted that its sibling had been sincere and unequivocal.

The adult, meanwhile, seemed to implicitly doubt the validity of the alarm because it kept foraging before it even bothered to take in the circumstance (and it kept foraging also after it had).

Perhaps it is of significance that the (supposedly subordinate) beaver splashed its tail when the kit had emerged above water and not while the kit was still safely below water or even in the den.

This might indicate at the expected ‘house chores’ by the subordinate whereby breeding adults take on the roles of territory defense (patrolling, scent-marking by the territory borders) while the subadults may be involved in raising the kits and looking after them.

Thusly, the subordinate might not have feel pressured to give alarm while only the adult was on sight (perhaps, just like children do, assuming that the adult was aware of our presence which it probably was; or forgetting to issue the signal on the first occasion due to the subadult’s psychological state caused by pre-dispersal exploratory aspirations + hormonal surge during the mating season and recalling the duty on the second occasion when the kit was around).

At this point, we walked off because, despite the zeroish temperatures, it was still a bit chilly while sitting in one spot (there was a lot of moisture in the air that probably added to the chill effect).

References

Campbell, Roo & Nouvellet, Pierre & Newman, Chris & Macdonald, David & Rosell, Frank. (2012). The influence of mean climate trends and climate variance on beaver survival and recruitment dynamics. Global change biology. 18. 2730-42. 10.1111/j.1365-2486.2012.02739.x.