I am creating this post after having observed beavers for some time now.
It always amazes me how ‘wobbly’ they can appear when they climb the riparian slopes to forage and when they drag branches or carry mud, or when they groom themselves.
Meanwhile, they are extremely agile when they have spotted a threat suddenly and their movement during flight is anything but slow, awkward and graceless.
They are quick and they make fast decisions and they can slide down the slopes most elegantly disappearing under the water with no sound at all.
These two types of behaviours that appear in stark contrast with one another have made me wonder what determines the ‘overall’ shape and movement of a species.
Namely, beavers (and perhaps, badgers, as well) can seem predominantly awkward trudging on in short, ‘tottering’ steps.
They are full endowed with the capacity to move in a very fast, agile and flowing manner.
However, it is not how they mostly present themselves.
It made me consider how body shape is created as well as how the modus operandi movement style is formed.
I believe it is related to how the species spends most of its time and what its most fundamental activity entitles.
For example, beavers and badgers both spend most time either paddling with their feet (in the case of the beaver) or walking in short, cautious steps because their feeding activity does not involve long runs but rather careful selection and (in the case of the beaver) transportation of resources.
Their activity is fixed to a rather limited area and demands precision and patience rather than it demands endurance in terms of racing and making long strides.
This should have ‘designed’ the species’ appearance and its manner of moving about.
Of course, this theory is not novel and many species have been researched with respect to morphological adaptations to foraging or movement strategies (e.g., aerodynamics, elongated shape to lower water resistance, wing morphology, supinant joints etc.).
However, frequently, these studies analyze very specific attributes (although, e.g., functional types of bats have been classified in accordance with body morphology and feeding behaviour such as hawkers, trawlers and gleaners).
I am not claiming to have discovered something incredibly original here.
I merely wonder if there are morphological qualities shared among species that exhibit similar predominant behaviour and what we can tell about an animal’s daily habits by looking at its body shape and movement style (e.g., how wading birds have longer legs than arboreal songbirds and how they use their legs differently raising them high above the ground).
I think it would be less useful than it would be fun to create a database of behaviour-specific morphological qualities that are indicative of specific lifestyle and then to see if it is possible to determine the species’ predominant activity by evaluating its morphological and movement style properties within the context of the database.
It might be also interesting to trace the limits of a species’ capability of exhibiting certain morphological qualities or movements outside of the regular activity pattern (e.g., fleeing in beavers).
For example, wolves, due to their need to keep running for long distances and to gain great speed temporarily, have lost their ability to use paws in the same manner in which bears can use their paws (supination).
Thus, wolves and bears have selected different lifestyles which have limited the bear’s ability to demonstrate fast run and long run while wolves cannot handle objects in the way bears can.
There are likely states in species’ evolution where some properties have been lost as a certain lifestyle is acquired (and other properties are gained) ultimately determining what the species would look like and how it would move most often.
I would, personally, enjoy acquiring more and more of such knowledge because it would be helpful in learning something about a species that has been encountered perhaps for the first time simply by observation.
Also, it would be helpful to look up a previously unknown species in an encyclopedia if some of the behaviour/habitat use/foraging style etc. can be deduced from its appearance and gait.
It can be hard to find a species in an encyclopedia without knowing its family or genus.
I find it fascinating that what we choose to eat and in what substrate (environment) we choose to spend most of our life determines what we look like, how we perceive the world (what we can see, hear, smell etc.), it affects who our predators are (who can catch us), how cold or warm we will feel.
Essentially, it determines not just who we become but what the world becomes to us, how we experience our days (fast vs. slow, many vs. few new impressions, interaction with plants vs. animals etc.).
It can even impact how we can show affection to one another (using paws or beaks etc. to groom one another) and what our parenting style would be (communicating mainly in vocalizations or via touch).
It can impact how we will come to perceive love, caring, safety, good life and what our values will be.
‘You are what you eat,’ acquires a new meaning when considered from perspective of how our daily foraging which tends to be the dominant activity in most species determines all of the properties discussed above.
I suspect that animals also use this classification strategy to evaluate newly met species in order to determine them for competitors, predators, prey or neutral to their own purpose.
It would be impossible for an individual, during their infancy, to have encountered a representative of every single species that they are to meet during their lifetime and that might be important to recognize because they pose a threat or an opportunity to their own survival; and it would be impossible to have learned all the appropriate reactions from their parent(s).
Perhaps animals classify some of the qualities they observe to generalize from the species that they have met to species that are new to them.
For example, a small mammal might have encountered a stork during the period of dependence and learning from parent(s) and later they would be weary upon meeting, for example, a crane because they have learned to associate certain morphological features and movement styles with danger.
I see it as a very beneficial strategy that can, of course, sometimes lead to incorrect assumptions, e.g., when a certain species has developed toxic defenses although otherwise it does not overly stand out from its genus or family, or guild etc (for example, frogs and toads).
These ideas are also fascinating because adaptations to certain lifestyles and the respective morphology, movement and pace is not unlike the ancient mythological perceptions of rhythms that pervade the natural world leading into a harmony which is how, e.g., shamans would call upon certain animal spirits or forces (by appealing to specific rhythm).
It would mean that the world is a musical and choreographic composition where everyone gets to play their part that is unique due to niche partitioning.
Even very similar species have to adapt to one another’s presence by acquiring differential foraging habits, differential use of space or differential temporal activity that can lead to slight variation in the lifestyle of that species and the respective external representations of the lifestyle.
If too many individuals demonstrate the same rhythm (or other features that I have mentioned), this leads to overexploitation of the habitat and imbalance.
If not enough individuals demonstrate a certain rhythm, this creates an vacancy (a silence, a stillness) that needs to be filled by something that fits the harmony in order not to lose important connections to keep the polyphony intact as a harmonic composition.
Maybe animals can even hear it. We can. People have expressed concern, e.g., over the lack of cricket chirping or bird song which suggests to us that things have changed and not for the better (the silence does not seem enjoyable).
Falling out of this rhythm specific to the species and the more ‘universal’ harmony, is dangerous.
I believe animals frequently apply caution when they have to alter their usual pace and their usual mode of moving or when they have to change their usual appearance – because these situations are the exception and they are often related to conflict.
For example, beaver takes on ‘quick elegance’ when it flees from a real or perceived predator.
It might be wise to heed our rhythm and our style and to be wary when a necessity arises to change it.
Because when we do and if the change is permanent, we also risk the harmony of the entire ecosystem.
Meanwhile, the ability to suddenly and temporarily pretend to be someone else (through manifesting different properties) is the trickstery that can save one’s life used in defense and competition and resource acquisition.
It can even be the form of ‘dramatic’ acting on the verge of one’s physical limitations that can lead to slow evolution of entirely new roles and new species over time.
The potential of these shape-shiftings (or pace-shiftings) to surprise prey, predators or competitors, in my view, also point at the strategy by animals to evaluate the life forms that they meet by their regular appearance and movement style (deviations causing confusion and leading to vulnerability).
Our lifestyle should be deeply integrated within the wider world (our ecosystem) but it is the wider world that commands also for us to look a certain way, to move in a certain manner, to lead a certain lifestyle with its adaptations that show in our body and our pace – in order to be a part of it for a long, long time.
For example, if our society demands us to take on a rhythm that tears us out of our ancient place in the natural harmony, we might become destructive because are too loud and too fast, and too bright for the composition that the Earth has been creating since the dawn of life.
***
I believe that the rhythm is also one of the mechanisms through which predators affect their prey (and the consequent trophic cascades) because predators introduce an altered pace in the ecosystem.
The absence or the presence of a key species (usually large species but also small species such as mosquitoes or small preferred forage items etc.) can modify how the rhythms fall into a composition through slowing it down or quickening the pace, or introducing more dynamic change throughout days and seasons.
Notes by Ieva 