Black Bear Ecology

Black Bear


Black Bears are large, heavily boned mammals. Adult males weigh from 250 - 650 lbs. and are 4-6 feet in length from the tip of their nose to the tip of the tail. Adult females are smaller, weighing from 100 - 400 lbs. and measuring 3½ - 5½ feet in length. Adult females reach maximum height and length at about 5 years of age. Adult males reach their maximum height and length when they are 7 or 8 years old. Most Black Bears in Ontario have a black coat colour although a small proportion ( less than 5% ) are dark brown to light brown.

Body weights of adult bears vary dramatically throughout the year, and from one year to the next, depending on food availability. In Ontario, adult Bears lose weight from the time they enter the den in the fall until well after they emerge from the den in the spring. In early July, berries and other soft fruits start to become available and adult Bears begin to gain weight. When food is abundant, Bears can gain up to 1 kg per day and can double their weight by Fall.

Distinguishing Age and Sex Classes

Adult Males have heavily muscled necks, shoulders and forelimbs, and have well developed muscle masses on top of their heads. Males also have broad snouts and their ears appear to be small because of the size of the head. If a male Bear stands up and faces an observer, it is generally easy to see the penis. If a male Bear is observed in a side view, long hairs hanging down from the penis can be seen in front of the thigh as it walks.

Adult females are more slightly guilt than males; they have small necks and have smaller frames. If a female bear stands up and faces an observer, it is generally easy to see the nipples. The long hairs that hang down from the vulva can be seen from behind as she walks.

Cubs of the year weigh about 5kg by late June ( the size of a small cat). They grow to 35 - 65 lbs by fall.

Yearlings weigh 45 - 65 lbs by late June, and by fall may be 40 - 45kg. Body growth in Bears is highly dependent on the available food supply.

1 kg = 2.21 pounds