Mature Forest Key To Virginia Black Bear’s Success

It’s the time of year when human thoughts, especially mine, turn to spring. Looking out at the snow-silhouetted trees, the birds and their fluffed feathers, the glassy knives of icicles dangling from the eaves, it is difficult to imagine that green, growing things exist. But change has already begun. Since the winter solstice, the days have lengthened. The earth is tilting our hemisphere toward the sun; snowdrops dangle white earrings above the snow. And in the depths of the Southern Appalachian forests, female American black bears have given birth.

I confirm such knowledge, not through textbooks or the Discovery Channel, but through the cries of five-day old black bear cubs as they are brought squalling into the Center for Ursid Research laboratory at Virginia Tech. The cubs are invisible at first, swaddled as they are in volunteers’ coats and sweatshirts, but their voices announce what their wrappings conceal. They howl like angry teakettles, demanding to be returned to the warmth of their mother.

At birth, American black bears look like giant moles, covered with a smooth, grayish pelt of hair. Their ears are tiny, black shells. Their eyes are squeezed shut and do not open for about five weeks, during which time they grope through the dark world, using only smell, touch, and vocalization to locate their mothers. Their heads seem disproportionately large, especially in the mouth region. When one yawns here in the lab, a huge, grooved palate opens into a pink-tongued cave. These cubs are made to do only one thing right now—guzzle as much milk from their mothers as they can get.

Considering their current size of about 8 ounces and only 6 inches long, the fact that males can reach up to 500 pounds and 6 feet in length seems astronomical, especially when compared with human growth potential. Yet, this strategy has worked for over 2 million years, allowing bear mothers to make efficient use of resources throughout the year. Virginia black bears mate in mid-summer, usually from late June to August.

But through an elegant process scientists are still trying to understand, females delay implantation of fertilized eggs until early December when they enter their dens. After a gestation period of about 55 days, cubs are born in late January or early February. The new family emerges usually in late March to mid-April, joining the rest of the population in the quest for food.

The Cooperative Alleghany Bear Study (CABS) at Virginia Tech has been studying such fascinating issues for the past ten years. The study was initiated in 1994 through a contract with the Virginia Department of Game and Inland Fisheries.

In particular, the project aims to discover the population growth rate and density of Virginia’s managed population, to assess the factors that affect the population, and to determine habitat use in relation to forest management practices. All of these objectives will aid CABS in recommending a long-term management strategy for Virginia’s black bears. In addition, captive studies are helping wildlife scientists and other researchers to understand issues ranging from nutritional requirements of mother bears to human depression.

This year marks the final data collection season for the study. Over the past summer, the project’s technicians, wildlife biologists, and volunteers trapped 335 bears along Virginia’s Blue Ridge Mountains. Some of the bears were fitted with radio collars or ear-tag transmitters that allow CABS members to monitor the bears’ movements. Now, as winter lumbers toward spring, the CABS team is locating the bears in their dens. They are particularly interested in finding females and new cubs, as this information will further their efforts at correctly estimating the population, and add to their knowledge about recruitment and successful bear reproduction.

Though all the data have not yet been analyzed, preliminary results of the study suggest a stable, perhaps even increasing, population. Dr. Michael Vaughan notes that the bears are exhibiting “good reproductive rates and high survival, and are moving into areas where they have not been seen for many years.” Currently, the Virginia bear population is believed to be around 3,500 to 4,000, but Dr. Vaughan and his collaborators suspect the number may be even higher.

The presence of mature forests is a key factor in the growth of the bear population. Bears rely heavily on hard mast, especially acorns and hickory nuts, to provide the fat reserves crucial for surviving winter. Hardwoods are also important sources of den sites, particularly for adult females. CABS has found that in the southern Appalachians, 70% of bears den in trees with large cavities. Red oak, chestnut oak, and poplar are the most frequently used tree species.

Large tracts of mature forests also provide enough habitat area for established home ranges and dispersal. Females usually need 12 to 15 square miles of habitat, and these ranges often overlap with their female offspring. Males, however, are forced to disperse, either by their mothers or other males, usually from five to 40 miles away. Eventually, their home range may cover an area from 50 to 75 square miles. Forest management that is sensitive to the bear population’s need for mature forests is extremely important, and the U.S. Forest Service has played a significant role in supporting CABS and providing the study with pertinent forest information.

Human-bear interactions are another crucial piece of the bear management puzzle. As the bear and human populations grow, they often come into conflict. As has been seen around the U.S., a keen sense of smell and a need to store as much energy as possible often leads bears to some odd places: birdfeeders, garbage dumps, and beehives, among others.

Since adult black bears are Virginia’s largest mammal, humans and other bears are their only predators. Like many U.S. populations, Virginia black bears are managed partially through hunting. The Virginia Bear Hunter’s Association has cooperated extensively with CABS, supplying funding and vital information about hunted bears. Last year, around 1,000 bears were harvested in Virginia, a number consistent with the growing population trend.

Education is still needed to aid people in understanding how they can best live with bears. People in rural areas, in particular, must learn to pay closer attention to how they store food and dispose of garbage. As more urban people seek the country life, they must also learn that deliberately feeding bears only exacerbates the problems that bears already face. The bear management plan may help meet these challenges because it was developed, as Dr. Vaughan notes, “in conjunction with all public stakeholders, including focus and interest groups from all walks of life in the region who have an interest in bears.” It is to be hoped, therefore, that as more people become interested in bear management, we will reach a consensus on how best to share the beautiful mountains we inhabit together.

Thinking of all these things, I cradle one of the cubs to my chest. As he is subjected to the dubious distinction of being photographed, measured, and weighed, I know I am holding the promise of spring, and the future of Virginia’s black bears, in my hands.

Tiffany Trent works with the Center for Ursid Research laboratory in Blacksburg. The author would like to thank Dr. Michael Vaughan, Colleen Olfenbuttel, Jen Hebert, John Chelko, and Andrew Trent of CABS for help with this piece.


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