Bears are seen by people in so many different lights. They’re ferocious killers, cuddly friends, pests and even gods. Think of them what you will but there’s no doubt that bears have left a lasting impression on people all over the globe!
Bears at a Glance
All bears no matter their species appear to be stocky, muscled and furry with long snouts and small rounded ears. They have a great diversity of coloration which reflects their habitat and their lifestyles and inhabits the continents of North America, South America, Europe and Asia, mostly sticking to the northern hemisphere.
There are only 8 species of bears that exist in today’s world, most perished before man had evolved. Every species that have avoided the fate of their extinct relatives are very much built for survival: being fast runners, skilled climbers, and decent swimmers which are all skills that help them traverse the environments they reside to find food, shelter, and mates.
Most bears, even the smaller species, can come across as quite intimidating; after all with their large claws, sharp teeth, and strong jaws, they’re well equipped for a carnivorous diet, however, the diets of a bear can vary quite greatly.
Polar bears, for example, have a predominant preference for meat and actively hunt their food; it makes sense since not much foliage grows in the frozen wastes that they inhabit. On the other hand, Panda bears feast almost entirely on bamboo, there’s plenty available in their habitat.
Between the polar bears and panda bears, the six other species of bear are different degrees of omnivore; feasting on the meat of animals they have hunted, scavenged and the fruits, plants, and shoots that they have foraged.
When it comes to interactions with humans, it depends on the bear species. Larger species of bears are definitely braver and can be quite a dangerous pest in North America and Canada when they arrive in a suburban town foraging through trash for food.
They can also be curious around hunters and fisherman so it’s defiantly advisable to take precaution when you are entering their habitat. Smaller species such as black bears can be shooed away easily enough if the person doing so has a lot of confidence but they are still powerful creatures so never approach or provoke them under any circumstances.
Bear Classification and Phylogeny
Bears are described as all the carnivorous mammals that belong to the family Ursidae that possess the traits described above. Ursidae belongs to the order carnivore, a diverse group of meat-eating animals, that is split into two suborders which describe the creatures body structure and hunting tactics: Feliformia (cat-like) and Caniformia (dog-like), the second of which is where bears belong.
There are three extant sub-families of bear: Ursinae, Tremarctinae and Ailuropodinae and there are four other families of bear, which are now extinct. One of the extinct families includes Hemicyoninae which are an ancient, formidable predator that existed during the Oligocene and Miocene described as “dog bears” referencing their structure resembling a half dog and half bear.
In terms of the evolution of the Ursidae family, it started with creatures called Parictis and Allocyon unlike the bears of today, and more like raccoons. They were most likely to have had omnivorous diets which consisted mainly of insects and originally inhabited North America.
Bear Species by Family
Ailuropodinae only has one extant member in the subfamily and that is of the Giant Panda. It is shown that there are many more species of Panda that inhabited the earth which had variable diets but evolved to become more herbivorous over time.
Giant Panda (Ailuropoda melanoleuca)
These iconic black and white colored bears are native to the highlands of China and feed on the abundant bamboo which grows there. It does, however, feed on other sources including shoots, fruit, leaves and even scavenged meat despite bamboo making up 99% of their diet.
Their status is threatened due to the vast reduction in their habitat as a result of deforestation, the expansion of agriculture and other human developments. There is a huge conservation effort that’s been ongoing; trying to maintain and restore the population of wild panda bears.
There are two subspecies of Panda, Ailuropoda melanoleuca is the nominate subspecies which means it is the subspecies that people are most familiar with whilst the other subspecies is Qinling panda that’s not black and white but light brown and white.
Just like Ailuropoda, Tremaexrinae is a family of bears with only one surviving species and many that are extinct; the Spectacled Bear.
Spectacled Bear (Tremarctos ornatus)
Like the other extinct members of this bears family, the spectacled bear is a short-snouted bear which gives it its alias; the Andean Short-Faced Bear. Its name also gives a clue to its habitat, and it’s the only surviving bear species on the South American Continent.
Its also the largest land carnivore found in South America although it’s not an obligate carnivore and, in fact, its diet only consists of 5% meat. The rest of the food sources on its menu consist of insects, fruits, shoots, and other plant matter.
The Spectacled Bear is a medium-sized species of bear and is just about the size of an Asian Black Bear. They have black matted fur with beige to ginger marking on its chest and face which are used to differentiate between individuals as no two are the same. Some don’t have the markings at all.
Other than the Giant Panda, Ursinae contains the most recognizable species of bear that people know of. These are the long-snouted and stout bears such as the black and brown varieties.
Sloth Bear (Melursus ursinus)
The sloth bear is a lesser-known species of bear that makes its habitat on the Indian subcontinent which includes Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka.
Compared to other species of bear, they’re lankier with longer shaggier coats. They present sexual dimorphism (a differentiation between males and females) with males being larger and heavier and females having more fur between the shoulder blades. You can see where they get their name because form some angles they do look kind of like a sloth.
They love termites and are what the menu of a sloth bear primarily consists of. In fact, they have smaller molars than other bears and lack upper incisors which allow them to basically hoover up termites. They have a very keen sense of smell and can detect grubs that are 3ft below ground.
They also supplement their diet with fruit and plant matter including the petals of flowering Mowha trees. Although it’s rare they have been documented to have hunted other mammals too.
They can coexist with other bear species in national parks like the Asiatic Black Bear and Sun Bear but can be predated upon by big cats. Some tigers have been noted to take to hunting the sloth bear whilst others avoid them, the same goes for jaguars.
Sun Bear (Helarctos malayanus)
Sun Bears, also known as Honey Bears, have jet black, sleek and short fur with a typically paler crescent-shaped marking just above their chest. They are the smallest species of bears and inhabit the tropical forests of South East Asia, like the Panda Bear, are also threatened by Human activity.
They have very varied diets which are particular to the season. It’s mainly composed of shoots, tree bark and fruit whilst honey, bees, grubs and other insects playing an important role for their dietary needs.
These bears are quite social with members of the same species and even though they can be seen as docile and friendly, if they are taken by surprise they are fiercely defensive. They can be hunted by large cats much like the sloth bear which inhabits similar territories are but by far their most prominent predators are poachers!
Asian black bear (Ursus thibetanus)
This species of bear is also known as the moon bear as a reference to its crescent-shaped white marking on its chest. It’s native to Asia and takes to a largely arboreal lifestyle, living in trees to feed, rest, seek shade and evade danger.
The Asian Black Bear species is quite diverse within itself compared to other bears with 7 subspecies recorded that all have small differences form each other and are found to live in different locations.
They live in an array of environments ranging from forests and deserts to the snowy altitudes of the Himalayas and are even found in Russia. They’re quite large bears with shaggy fur and play some roles in folklore, particularly in Japan where they are associated with yamotoko or the “Mountain Man”
These bears are not picky eaters either, they will eat most insects they come across, preferring grubs but will also go for fruit, mushrooms, carrion, nuts, seeds, honey, herbs, garbage, and grain! They are indeed opportunist in their strategies for obtaining nutrition.
American black bear (Ursus americanus)
A medium sized bear that resides in North America; the black bear is fairly common in rural areas and woodlands. It’s the smallest species of bear on the American continent and has a whopping 16 recognized subspecies.
They like to live in areas that are mostly inaccessible to people with thick vegetation, high altitude and is heavily forested, but they are known to venture out from their homes to scavenge food from human habitation, they can be particularly pesky to hunters, fisherman, and campers.
Females can be distinguished from males as their faces are more slender and pointy. The Black Bears are smaller in size and have less concave heads than American Brown Bears, they also have shorter, greyish brown claws and do not have a bunch of fur on their shoulders.
They have been known to product hybridized offspring with other species of bear, although this is rare it can occur. For example, an Asian Black Bear escaped from captivity in Florida and bred with an American Black Bear.
Brown Bear (Ursus arctos)
The Brown Bear also called the Grizzly Bear, is the quintessential bear and one which is thought of immediately whenever bears are mentioned. They are dispersed throughout North America, Eurasia, and Europe and are the second largest bear, being beaten in size and weight by the Polar Bear.
Much like the American Black Bear, the Brown Bear also has 16 subspecies and would have been more but unfortunately, even though the bear is of least concern on a global scale, many subspecies have been the victim of local extinctions, as a result, human activity.
Their claws are very large and curved which is very useful in many of their activities, from gather food to marking territory by scratching bark from trees. They congregate in large groups annually by fast-moving waters, in salmon spawning as salmon are a nutrient-rich food source for bears at this time of year but their diets are omnivorous overall.
What’s quite interesting about the Brown Bear is that it has the largest relative brain size compared to other animals classified as Carnivoran and have been seen using tools. The use of the jagged rocks to scratch their backs shows some high cognitive function.
Polar Bear (Ursus maritimus)
Polar bears, as mentioned throughout this article, are the largest species of bear and the only species which has completely white fur. After all, white fur is a great adaptation to the snowy habitats in which they live; the Arctic Circle.
Another adaptation to their environment that they possess is their great ability to swim, this they use as a hunting strategy to catch their favorite prey which is seals. They are also known to locate seals that bury themselves within snow using their acute sense of smell and then pounding down onto the burrow to free the seal and catch it.
When compared to a brown bear, their legs are stockier, paws are larger, the claws are shorter, their body is more elongated their ears are smaller and their fur is layered and thicker; all of which give them a greater chance of survival in the frozen wastes when it comes to warmth, swimming speed and gripping their prey and on ice.
Due to global warming, polar bears are suffering greatly from habitat loss, as the frozen place that they call home is melting and creating more oceans. This is resulting in stray polar bears venturing into rural towns in northern Canada to find food which is a danger to the residents.