One Life: Bears

One Life

World Bear Day

By David Neale, Animals Asia's Animal Welfare Director

Bears belong to the family Ursidae. They can be as small as four feet and 60 pounds (the sun bear) to as big as eight feet and more than a thousand pounds (the polar bear) and they’re found throughout North America, South America, Europe, and Asia.

There are eight species: Asiatic black bears, brown bears (which include grizzly bears), giant pandas, North American black bears, polar bears, sloth bears, spectacled bears (also called Andean bears), and sun bears.

Bears demonstrate complex emotional and cognitive abilities. They are excellent communicators, have great memories, problem solve, learn from each other and they are capable of performing cognitively complex tasks.

Bear communication

The ability to communicate effectively with others plays a critical role in the lives of all animals. By doing so they can infer intentions and emotional states, and adjust their behaviour accordingly. Bears are visual, vocal and chemical communicators.

Visually they communicate by the way in which they behave in the presence of each other, a bear moving away, sitting or lying down is likely to convey a level of subordination, whilst walking or running towards a rival conveys more dominant behaviour. Adult polar bears wag their heads from side to side to indicate they intend to interact playfully rather than aggressively, and at times of food scarcity a grown polar bear offspring may approach their mum to ask for food, approaching slowly, circling the food, and gently touching the feeding bear’s nose to say that “I come in peace”.

Sun bears use facial expressions to communicate their desire to play with another bear, often mimicking the facial expressions of other bears during periods of social play in a similar way to humans and apes.

Vocally, bears use growls, huffs, barks, and roars to tell other bears what they are doing and how they are feeling, and other bears understand the meaning of these sounds. If a bear is not receptive to the approach of another they may roar loudly, growl, hiss, or snort to show their anger and aggressive intentions. If these warning signs do not work, they may charge forwards with their head down and their ears laid back.

Polar bears cubs have a wide range of vocalisations to convey their intentions, emotions and needs to their mums. If a cub cannot find its mum, or simply does not get its own way, it produces a distress cry. If a cub is simply not in a good mood, it produces a series of moans and groans to convey its discomfort. If it is hungry it produces a gulping sound to let its mum know it is ready to eat, and when a cub is content, during or following a feed or when dozing or sleeping, it produces a contented hum.

The cubs chatter instigates a response from mum, if she feels stressed due to the moans and groans of her cubs she is likely to produce her own chuffing sound in response, and when she is engaged in a grooming session with her cubs she will also produce her own contented vocalisation.

Bear senses

Chemically, bears urinate, defecate and rub themselves against trees to leave their scent for other bears to detect. Brown bears twist their feet into the ground as they are walking, leaving a scent made up of a variety of chemical compounds, produced from the foot glands, that inform other bears about them as individuals, who is around, who they have to avoid and who they would love to meet. This is repeated by others, which step exactly in the same places, leaving a trail of smelly holes in the ground full of information for other bears to explore.

Fortunately, bears have an excellent sense of smell and use this as a key sense to collect such information about others within their environment. A heightened sense of smell is particularly important for polar bears who need to be able to locate their prey over very large distances. Polar bears can reportedly smell seals and other animals up to 9 km (5.6 miles) away. They can even smell the breathing holes seals create in the ice from almost one km (.6 miles) away.

Bears also have good memories. Throughout the year, bears may eat many different types of food, and they have to remember where to find these foods and when they are ready to eat. A bear can remember where they found a certain type of food that it ate over ten years ago.

Bear play

Bears also share their living area with many other individuals, they interact with each other, and need to remember familiar individuals throughout their lives, recognizing them and understanding their social status and their previous encounters.

And of course, bears like to have fun and play with each other, with play bouts helping them develop socially whilst also helping learn essential survival skills. Cubs are particularly playful and they enjoy chasing after and tackling their siblings and also fight with their mother too. This play has very distinct ‘unwritten’ rules that bears learn to understand; a more dominant, stronger individual must be able to adjust his or her actions to meet the needs of the other individuals involved. Making a moral decision not to harm others to ensure continuation of the game.

Bears as part of the ecosystem

Asiatic Black bears also indirectly provide food for other animals on the forest floor by dropping oak acorns and pine nuts as they forage in the trees. Wild boars have even been observed to follow the acoustic and olfactory signals produced by the bears to find them in the trees and subsequently benefit from the windfall.

As grazers, bears are very good for the forest ecosystem, they eat fruits, and the seeds of the fruits are planted back into the soil when the bears poo. The seeds then grow in the new area they are deposited within, helping to maintain a healthy natural environment.

And finally, bears also play an important role in the lives of other animals. Black bears in North America play a significant role in protecting grey foxes from coyotes, who compete with the fox for food and space. During the summer the grey fox stays close to areas populated by black bears, and in doing so they gain protection from the coyotes. But in the winter, when bears hibernate, coyotes are three times more likely to move into the now vacant bear territories and the grey fox, no longer secure by the presence of the black bear, often is forced to move out.

Bear cognition

Asiatic black bears, black bears, spectacled bears and sun bears have impressive ‘bed-making’ skills, making ‘beds’ and resting areas in trees by bending tree branches together. Some individuals have also demonstrated impressive tool use and problem solving abilities. Brown bears have been observed moving tree stump’s and boxes in order to stand upon them and grab a food item that has been placed out of their reach. Brown bears have also been seen using barnacle-covered rocks to scratch irritated skin or remove food from their fur while moulting.

Bears can also outsmart us in their efforts to avoid capture, with individuals known to roll rocks into bear traps to set off the trap and eat the bait in safety, and a bear in Montana seen to dismantle an electric charge used to protect a dead deer before being able to steal the quarry.

Bears have other cognitive abilities too, in behavioural experiments, captive american black bears have shown that they canperform numerical tasks, distinguishing the number of dots on an image, demonstrating a counting ability. Bears have also demonstrated an ability to recognize things they know in real life, such as pieces of food or humans, when looking at a photograph of the same thing, transferring learning with real objects to photographs of those objects presented on computer screens. This ability has also been demonstrated in captive sloth bears.

American black bears are also known to perceive the risks of crossing roads, demonstrating an increase in their heart rates as they approach roads, with larger increases when individuals cross busier roads. A bears’ recognition and alertness to human-related threats being adaptive for living in human-altered landscapes.

Bear emotion

In addition to being cognitively complex, bears are emotionally complex too.

Mother bears are affectionate, protective and attentive toward their cubs, raising them to an age where they can survive on their own. Depending on food abundance, some mothers may keep their yearlings a second and in some cases a third year, denning together again and breaking up in the third or fourth year. Bear mums care deeply about their family and they will risk their lives and even fight to the death to save a cub or sibling from danger.

Mums teach their cubs how to hunt and protect them from danger, and they ‘talk’ to each other and understand how each other is feeling through their vocalisations and understanding of their behaviours.

In the winter, polar bear mums give birth to 2 or 3 cubs, in dug-out overwinter dens. Mums may go without eating for up to 8 months, surviving only on their body fat while over-wintering and feeding their newborn young. The cubs and mum remain in the den until the early spring when they emerge to see the outside world for the first time.

Polar bear mums have been observed carrying cubs on their backs when navigating through icy waters hunting for seals. The cubs are not adapted to cope with the cold water as they do not yet have a fat layer sufficient to avoid chilling if swimming for any prolonged period of time. By carrying the cubs on her back, mum helps to minimise her cubs exposure to the cold, and helps to transfer cubs not yet able or willing to swim.

Bear cubs learn from their mothers how to find food and how to stay safe, and by the time a juvenile bear leaves its mum, it knows what foods are available at each time of the season, and what habitats are likely to have those foods over a very large area. That knowledge serves them well as they move into new areas, learning and remembering where new food sources are found in a new environment. This knowledge is also critical to finding food when food sources change drastically from year to year depending upon weather and climate.

Bear conservation

Six species, including the polar bear and the giant panda, are included on the IUCN Red List as threatened or vulnerable.

Polar bears are listed as a vulnerable species, there are thought to be around 26,000 polar bears worldwide and this number could drop dramatically in the next few decades. Polar bears need ice to hunt, travel, and raise their cubs. Global warming is causing their ice to melt and this is threatening their survival. As the Arctic warms polar bears are becoming increasingly cut-off from their main hunting grounds. This is particularly challenging for females with cubs, as cubs do not have the thick layer of fat they need to survive the cold water. Mother bears are therefore reluctant to swim with young cubs, restricting their access to food considerably.

Human activity in the Arctic has also dramatically increased with further oil and gas extraction, increased shipping, mining and tourism. All of these activities present a threat to the polar bears and their way of life.

The Asiatic black bear has been hunted for centuries for its skin, paws and for the gallbladder, which is used in Oriental medicine. Recent deforestation across the Asian Continent is a major threat to the survival of the species. Habitat is cleared by logging practices, development and an encroaching human population. These bears may also be labelled as a pest and consequently persecuted in some areas as they can destroy crops.

The majority of the Sun Bears’ forest habitat has also been destroyed by logging and conversion to agriculture. In addition to levelling the forest, logging roads create convenient access for poachers. The demand for bear products is a major threat to all bears. Traditional Asian medicine prescribes bear bile, spinal cord, blood, and bones for complaints ranging from baldness to rheumatism. In addition, Sun Bears are at times illegally kept as ‘pets’, the mother bears being killed in order to obtain the cubs.