The Science Behind Algonquin's Animals - Seasonal Movement Patterns and Feeding Habits of Adult Black Bears in Algonquin Provincial Park
  Research Projects Seasonal Movement Patterns and Feeding Habits of Adult Black Bears in Algonquin Provincial Park

Common Name American Black Bear
Scientific Name Ursus americanus
Other Names Black Bear

General Appearance: Next to the Moose the Black Bear is the largest mammal in Algonquin Park and the only bear species in the Park. There are approximately 2,000 bears in Algonquin which is about one for every three to four square kilometres. Despite the size of the population, Black Bears are reclusive and tend to avoid contact with people unless, through human carelessness, they begin to associate humans with food.

Most people are familiar with the appearance of Black Bears from television, zoos or a quick glimpse of a bear in a summertime berry patch. Black Bears stand about one metre high at the shoulder and are about 2 metres in length including a short stubby tail. The face of a Black Bear shows a snout tapering into a broad head with small, rounded ears. The head, neck, and shoulders are in a straight line and lack the prominent shoulder hump of Grizzly Bears (Ursus arctos) living in western North America. A Black Bear's fur is dark black or brown in colour, sometimes showing a slight white patch on the chest.

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Weight: The Black Bear is Algonquin's second largest mammal, next to the Moose. Despite this, the size of a bear is often deceiving, with most observers over estimating the size. Female Black Bears in Algonquin Park weigh between 45 and 70 kilograms. Males are usually larger, weighing between 70 and 150 kilograms. A bear's weight is dependent upon the age of the animal (usually older bears are heavier) and, more importantly, the time of the year. For example, a Black Bear entering hibernation in the fall may weigh 60% more than it did when it left hibernation the previous spring. The largest bear ever recorded in Algonquin Park weighed 228 kilograms.

Migration: Black Bears do not migrate, however, bears (especially males) do have very large territories which they cover in order to find seasonally-abundant food sources. Male bears may have territories that are up to 140 square kilometres in size, with females having territories of only 10 to 50 square kilometres

Food Sources: Black Bears are omnivores, meaning they will eat anything they can obtain, whether it is plants or animals. Plant matter makes up 95% of a bear's diet. In the early spring they feed heavily on grasses and also utilize White Suckers found in shallow creeks and streams. As leaves start to appear on the hardwoods in early June, Black Bears begin to feed on aspen leaves. By mid-summer their attention turns towards different types of berries and seeds. As fall approaches, bears will feed heavily on beech nuts, acorns, and cherries. Throughout the year, bears also utilize any other available food source, consuming insect larvae, insects, and salamanders, all of which may be found inside or under rotting logs and stumps. During the early summer, adult male Black Bears will prey on deer fawns and Moose calves if the opportunity arises. Being very opportunistic, adult male bears will also prey on bear cubs and, rarely, other adult bears and carrion. They will feed on human garbage if readily available. This only occurs when campers do not store their food and garbage properly, and with bears that wander outside of Algonquin Park where there are open garbage facilities.

Bear Feeding on Beech Nuts in tree (No Audio)

Bear Feeding on White Suckers in stream

Sounds: Black Bears typically do not vocalize. The most common bear sounds are grunts, used when playing, and loud blowing, indicating the Black Bear is nervous or afraid. The Black Bear uses a resonant voice to exhibit strong emotions and most often used by cubs. Adults will use their resonant voice when they are in pain or are frightened.

Listen to the sounds of a black bear sniffing

Major Predators: Adult Black Bears have few predators - these include humans and adult male bears. Bear cubs may be killed by adult male bears.

Breeding: Male Black Bears will compete for, and mate with, as many females as possible. Mating takes place from late May to early July but fertilized eggs do not start to develop until late fall. At the end of January, while asleep, a female generally will give birth to two cubs, and nurses them until she awakes in the spring. A cub stays with its mother throughout the next year, therefore, female bears mate only every other year.

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Research Procedures: Large adult male Black Bears were studied during a five-year period in Algonquin Park from 1992 through 1997. This study provided information on the seasonal movement patterns and feeding habits of bears.

During the study, 18 adult males weighing more than 120 kilograms each were fitted with radio-telemetry collars.

Trapping efforts were concentrated during the fall and spring throughout the study period. Bears were caught in trailer-drawn culvert traps and injected with an immobilizing drug using a jab stick or rifle. Once a bear was immobilized, it was weighed, sexed, and any physical markings and abnormalities were recorded. A premolar was extracted to age the animal accurately. In 1995, hair samples began to be collected for DNA analysis. Every captured bear was given an two ear tags with an identifying number. Upon completion of collection of data, the bear was given an injection to reverse the effects of the tranquilizer.

Radio-tracking of collared bears was undertaken three times per week from den emergence in the spring to den entry in the fall. Tracking was done randomly during the day and night. Aerial telemetry was done in either a fixed-wing aircraft or a helicopter and ground readings were taken for locating individuals through triangulation on 1:10,000 Ontario Base Maps or 1:50,000 topographic maps. Using the minimum convex polygon method, breeding ranges were established. Food sources were determined by walking into areas which had been frequented by a bear for two or more days. Transects were walked by researchers to look for obvious bear signs such as tracks, scat, beds and sources of food. The locations of dens were confirmed by entering them to determine its use by a bear.

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Research Habitat: Black Bears live throughout the deciduous and coniferous forests of much of North America, from the Atlantic to the Pacific Ocean, and as far south as Mexico to as far north as the tree line.

Black Bears use all the five major habitats in Algonquin Park.

When camping in bear country, which includes Algonquin Park, remember the three simple bear safety rules.

1. Never feed or approach a bear.
2. Store all your food and garbage in the trunk of your car (or suspended high up between two trees if you are camping in Algonquin's Interior).
3. Keep a clean campsite and pack out all garbage.

To find out more about coexisting with bears and the Ontario Government's detailed Bear Wise program check

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Research Questions

How many Black Bears are there in Algonquin Provincial Park?

The number of Black Bears in Algonquin Park is difficult to determine. Bears are not active in the winter, therefore they do not leave tracks in the snow. This lack of tracks means they can not be censused like other animals such as wolves and Moose. A study of bear numbers in habitat similar to Algonquin Park near North Bay suggested a density of one bear per 2.4 square kilometres. If it is assumed conditions in Algonquin Park are similar, the above figure may be logical. A study done in the north part of the Park that trapped and tagged bears proposed there was one bear in every 3 or 4 square kilometres. Based on the results of this study, there may be around 2000 Black Bears in Algonquin Provincial Park.

What are the seasonal movements and feeding patterns of Black Bears in Algonquin Provincial Park?

In Algonquin Provincial Park Black Bears typically emerge from the den from late March to early April and begin to wander within their breeding ranges. The breeding territories of adult male bears in the Park were found to be between 19.3 km and 87.6 km, with an average of 40 km. However, ranges after the breeding season, which include post-breeding movements, were shown to exceed 1000 km_ for several males. These post-breeding movements usually occur between early July and the middle of August and last between 15 and 251 days. During the study, of all the collared bears, only two did not move outside Park boundaries after breeding.

Upon emerging from the den in the early spring, bears will move to clearings where they can feed upon grasses. They also feed on poplar catkins and leaves before more abundant food sources become available. In the early spring, White Suckers, which are spawning in shallow creeks, are an important food source for Black Bears. During the study, several bears were observed feeding on suckers and two collared bears spent between two and ten days at creeks with suckers.

Soft mast, such as elderberries and strawberries, are consumed by bears when they become available in June. As the summer progresses other food sources such as Pin and Choke cherries, raspberries, Juneberries, and blueberries become available and are an important food source until the fall. It is believed that the movements of bears after breeding are related to the availability of these soft mast species. Radio-collared bears typically moved from higher elevations to lower elevations where abundant soft mast crops were located. These movements were to the southeast and east, to areas where Juneberry and blueberry were abundant.

By September, hard mast such as beech nuts and Red Oak acorns become an important food source for Black Bears. The consumption of these hard mast species result in rapid weight gain. As with soft mast crops, bears will move to areas, often outside of Park boundaries, to where there are suitable hard mast crops. In the western part of Algonquin, where there are very limited stands of Red Oak, bears often have to move to lower, drier elevations to find an abundance of acorns. If there is a beech nut crop failure, as happened in 1993, bears will also be forced to move to areas where there is an abundant hard mast crop. Upon returning from summer feeding ventures, male Black Bears will feed in beech stands which are close or in home ranges for a further two weeks to a month when beech nuts are readily available.

Weight gain is critical in the fall for survival during the winter and bears will forage over large areas to ensure the adequate consumption of hard mast species before the denning period.

From mid-May to mid-June, predation of moose calves is assumed to be important to bears. During the study period, predation of moose calves by Black Bears was observed in five instances along with six other accounts of bears chasing cow-calf groups.

It is speculated that within Algonquin Park, where a significant number of adult male bears exist, intra-specific predation of smaller bears may occur. Two instances of cannibalism were observed during the study period. The first involved an adult male who pursued another adult male up a tree, dragged it down, killed it, and partially consumed it. The other instance involved an eyewitness account of a bear eating another bear. Investigation of the carcass failed to reveal whether or not it was a case of predation or scavenging.

Apart from natural sources of food, 54% of the radio-collared Black Bears ventured outside Park boundaries to utilize garbage dumps. For most of these bears dumps provided a large and sometimes main source of food. Most of the feeding activity by the large adult males occurred during twilight or nighttime hours with daylight hours spent bedded down away from the dump.

Suggested Reading
Educators: Learn more about Algonquin’s habitats, download readings and worksheets from the Educator Resources section of the Web Site, or you may also learn more through the following publications:

Mammals of Algonquin Provincial Park
Fifty-three species of mammals have been found in Algonquin Provincial Park. This book explains the life history of these mammals. The many illustrations help to make it easier to identify them, and the book also contains a useful reference chart for distinguishing tracks and scats.

more info

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