Animal Behaviors that Affect the Probability of Successful Reproduction in Black Bears (NGSS 6-8 Grade)

Black bear females give birth to their young while in their dens in a deep sleep – called torpor. The cubs stay snuggled up to their mother for warmth, nursing on her protein-rich milk until spring. When spring arrives, the female leads her small cubs out of the den and introduces them to the outside world. They will learn about foods they can eat, how to locate them and, in the case of fish, catch them. She will keep nursing them for almost eight months while they are learning. They will learn about predators, such as coyotes, mountain lions, and male bears, and other things that can hurt them. She will teach them to climb large trees to escape danger and they will practice staying up in the branches while she feeds on the ground nearby. They will learn to note these babysitter trees and will climb them when they feel threatened. The female bear will groom her cubs, licking off burrs and cleaning cuts and injuries. A mother bear knows the sounds her cubs make when they are hungry or frightened and will lead them to a safe place to nurse. If her cubs call out in fear or distress she will come running to protect them. This is why it’s important to never get between a female bear and her cubs.

The female bear will wean (stop nursing) her cubs in their first fall. By then, the cubs have learned the foods they need to eat to fatten themselves up for winter. They will stay with her in her den that second winter, but in the spring, when they are about a year and a half old, she will chase them away to start lives of their own.

Each of these behaviors of the female bear affect the probability of keeping her young alive – so increase the chances of successful reproduction.

Mammals generally have fewer young over their lifetime than other kinds of animals, but spend the most amount of time and effort protecting and training them until they can survive on their own. Think about each of the things the female black bear does to increase the probability of her young surviving. Compare her behaviors to other mammals, such as a squirrel, deer, or even a human.

Performance Expectations - Students who demonstrate understanding can:
MS-LS1-4. Use argument based on empirical evidence and scientific reasoning to support an explanation for how characteristic animal behaviors and specialized plant structures affect the probability of successful reproduction of animals and plants respectively.