In Brief...

Orientation

 

I struggled with what to call this higher-order section that deals with the intelligence and sensory facility of bear species. "Orientation" is a bit ambiguous because this term depends on context to be imparted specific meaning. But "orientation" does capture the essence of what the brain and senses offer an animal. The senses detect and upload stimuli from the external world, which are then given meaning through the integrative and information-imparting functions of the brain, to which virtually all of the senses are directly linked through the nervous system. This information is then given further meaning through pattern matching and reference to memory and other encoded features of an animal's "self-system." Taken together, all of this provides animals--including bears--with an ability to orient themselves to their world, often at multiple spatial and temporal scales.

 

The latter ability to scale information and orientation depends upon higher-order functions of the brain located primarily in the frontal (more specifically, neo-) cortex. And bears are especially well-endowed in this regard. They undoubtedly map themselves in relationship not only to their immediate circumstances, through the real-time functioning of their senses, but also in relation to a geospatial- and calendar-referenced reckoning of their past and projected experiences. All with the potential to not only respond appropriately to the immediate demands of their lives, but also to position themselves in time and space so as to successfully obtain mates, security, and food.

 

Anticipating the disposition of food resources is particularly important to a large-bodied omnivore--which grizzly bears are, along with most other bear species. But being able to assess the quality of foods upon encountering them is also critical. You can probabilistically anticipate where and when particular foods will be abundant and nutritious, but that reckoning is only probabilistic. You can place yourself in a field of yampa roots, but you still need to seek out the best and biggest roots, which depend on a combination of sight and smell. And you may be wrong about the quality and abundance of the roots during a particular season of a particular year. Which means you need to be constantly scanning and scouting for quality foods--whether part of your existing repertoire or not.

 

All of this bespeaks a natural marriage between higher-order mental functions (which provide a bear with the ability to abstract and conceptualize, both of which are key to anticipatory mapping) and immediate sensory input (which allows for appropriate adaptive responses to an unfolding situation). All mediated by the brain. And all ultimately providing an animal--in this case, a bear--with orientation to its world; past, present, and future. 

So, for bears, what distinguishes the organs of orientation and related sensory functions from those of other carnivores? Below is a brief overview, synopsizing information covered more thoroughly under Senses and Intelligence (see buttons above right):

 

  • In most of the ways that we humans reckon it, bears are probably more intelligent than any other carnivore, and in some ways as intelligent as primates such as chimps. Relative to other carnivores, this is evidenced by the comparatively large size of their brains and, of that mass, the comparatively large size of the frontal cortex and neocortex. These structures are the most closely associated of all with higher-order cognitive functions. Bears also perform at the level of primates in their abilities to abstract and generalize, which, aside from language, is indicative of highly developed intelligence. However, unlike many of the social primates, they don't seem to have a highly-developed visual sense of "self," which is evident (at least in experiments to date) in their failure to recognize themselves in mirrors. They see an "other" conspecific instead.

 

There is a general hypothesis that large brains such as those of bears were evolutionarily driven by the development of culture--bodies of knowledge shared among individuals and passed down through the generations. Theorists often closely associate culture with sociality, which obviously does not hold for the solitary bears. More likely, their large brains relate to the demands placed on any large-bodied animal of carnivorous descent (such as bears) when navigating all of the contingencies and choices associated with omnivory. No small challenge (see Nutrition and Physiology).

 

  • Perhaps with the exception of polar bears, sense of smell does not seem to be extraordinarily well-developed in ursids, contrary to "common knowledge." I do not mean by this that they have a poor sense of smell, simply that, compared to other carnivores such as canids or hyenas, they are not exceptionally well-endowed. The evidence for this contention is primarily physical in nature. The olfactory bulb of bears (the brain organ governing olfaction) is relatively smaller than that of canids and hyenas. The olfactory turbinals (structures in the nasal cavity associated with the uptake of scent) are average in development, with the apparent exception of polar bears. But in support of claims to superior olfaction, bears seem to have a greater volume and density of nerves communicating scents taken up in the nasal cavity to the brain. Is smell important to the life strategy of bears? Almost certainly. Are they exceptionally well-endowed in that regard? The answer is unclear.

 

  • The eyesight of bears is probably underdeveloped, but rendered in color. Again, as with sense of smell, the evidence for acuity of eyesight is not definitive. But their eyes are small in volume relative to the size of their skull. They also act myopic. On the other hand, the evidence for color vision is definitive. Black bears have been shown to reliably differentiate colors along all of the major gradients, with the possible exception of discriminating green from red. Similarly, pandas have been shown to reliably differentiate green, red, and blue. Added to this, of course, is an ability to differentiate shades of gray, from black to white.

 

  • We don't have a good sense of how well bears can hear. They are certainly not highly specialized in this regard. They seem to hear relatively well in the range of frequencies you would expect from their size. Plus they can hear (and emit) sounds at substantially higher frequencies. Moreover, they seem to have a considerable vocal repertoire, especially for a "solitary" animal. Aside from this, there is much yet to learn.

 

  • Insofar as the senses of touch and taste are concerned? At this point, who knows. Hopefully I can revise this entry at some point in the future.